Chemistry Form 4 A+ Notes

7/29/2019 Chemistry Form 4 A+ Notes

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SEPT 2013

PREPARED BY:


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CHAPTER 2: STRUCTURE OF THE ATOM

2.1 MATTER

1.

Matter : Any substance or material that occupies space and has mass. Exists as a solid, liquid or gas (3 states of matter). Made up of particles. 3 kinds of particlesatoms, molecules, ions Can be divided into elements and compound.Particles Description

Atoms Smallest particles of an element that retain the chemicalproperties of the element.

Examples : Sodium atom (Na)Zinc atom (Zn)

Helium atom (He)

Molecules Particles composed of two or more atoms. Can be with the same or different atoms Examples : Same atomsOxygen gas (O2)

Different atomsAmmonia (NH3)

Ions Charged particlespositive or negative Positive charged ion (Cation)Zinc ion (Zn2+)Negative charged ion (Anion)Chloride ion(Cl-)

Matter Descriptions

Elements Particles made up of the same atoms only. Can be in the form of atom or molecules. Cannot be split into two or more simpler substance by

chemical means.

Examples:- Metallic Copper(Cu), Iron(Fe), Gold(Au)- Non-metallic Oxygen(O2), Sulphur(S8)

Compounds Particles made up of two or more elements. Can be molecules or ions. Examples:

- MoleculesWater (H2O)Sulphur trioxide (SO3)

Tetrachloromethane (CCl4)- Ions Sodium chloride (Na+, Cl-)


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Iron(III) oxide (Fe3+

, O2-

)

Calcium chloride (Ca2+

, Cl-)

2.

Changes in states of matter Matter can change its state. Reversible changes. Exists in 3 states, solid, liquid and gas.

During the changes, the following do not change:- Mass of particles

- Size of particles

- Type of particles

Velocity of the particle increases when- Temperature increases- Kinetic energy increases

Melting pointBoiling point

SOLID LIQUID GAS


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Sublimation can only happen to :- Ammonium chloride (NH4Cl)

- Solid carbon dioxide / Dry ice (CO2)

- Iodine (I2)

Differences between solid, liquid and gas (Kinetic Theory Of Matter):(Essay)

States of matter Solid Liquid Gas

Arrangement of

particlescompact, orderly

manner

Loosely packed,

disorderly manner

very far apart,

random motion

Particles motionVibrate, rotate in

a fixed position

Move freely Move freely and

randomly

Particles Kinetic

energy

Very low Moderate High

Shape Fixed Not fixed (follow

the shape of

container)

Not fixed (follow

the shape of

container)

Volume Fixed Fixed Not fixed

Rate of diffusion Low Average High

Attractive forcesbetween particles

Very strong Medium Very weak


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3. Experiment (PeKa)a. Heating curve of naphthalene/acetamide Diagram:

Graph:

AB: Solid DE: Liquid + Gas

BC: Solid + Liquid EF: Gas

CD: Liquid


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Explanation:AB: When the solid is heated, heat energy is absorbed. This causes the

particles to gain kinetic energy and vibrate faster.

BC: The temperature remains constant because the heat energy absorbed by

the particles is used to overcome the forces between particles so that the

solid can turn into a liquid. At this temperature, both solid and liquid are

present.

CD: The particles in liquid naphthalene absorb heat energy and move faster.

During the heating of naphthalene:- Water bath is used (ensure uniform heating, naphthalene is flammable)

- Naphthalene is stirred continuously (ensure an even heating)

Water bath: For heating a substance which is less than 100C. Oil bath: For heating a substance which is more than 100C. Latent heat of fusion: heat required to convert solid to liquid without a

change in temperature.

b. Cooling curve of naphthalene/acetamide Diagram:


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Graph:

Explanation:RS: When the liquid is cooled, the particles in the liquid lose their

kinetic energy. They move slower as the temperature decreases.

ST: The temperature of naphthalene remains constant because the

heat loss to the surroundings is balanced by the heat energy given off

during freezing.

TU: The particles in solid naphthalene release heat energy and vibrate

slower.

During the cooling of naphthalene: Boiling tube containing naphthalene is placed in a conical flask. (to

minimize heat loss which may affect the accuracy of freezing point

air trapped in conical flask is poor conductor of heat)

Stirred by using thermometer (to ensure even cooling)

PQ: Gas ST: Solid + Liquid

QR: Liquid + Gas TU: Solid

RS: Liquid


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Super cooling

i. Condition in which the temperature of a cooling liquid drops below thenormal freezing point.

ii.

Occurs when conical flask is not used in the experiment.

2.2 ATOMIC STRUCTURES

1. Historical development of the structure of atoma) John Dalton

- All elements made up of small indivisible particles called atoms.

- Atoms made up of tiny particles which cannot be created or destroyed.

- Atoms of same elementsame mass

- Atoms of different elementsdifferent mass

- Atoms join together to form larger molecules or compounds (in simple

ratio)

- Weakness:

Atoms are not the simplest particles bigger than proton, neutronsand electron

Atoms can be destroyed or breakdownradioisotopes Atoms of same element have different massisotopes


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b) J.J. Thomson

- Plum pudding model.

- Electron embedded in a sphere of positive charge.

- Electron spreads randomly throughout the positive charge.

c) Ernest Rutherford

- All positive charge of an atom is concentrated in the nucleuscontainprotons.

- Mass of atom is located in a small area (nucleus).

- Number of protons = number of electron

d)Neils Bohr

- Electrons of atom are arranged and move around the nucleus in orbital

called electron shells.

- Nucleus contains protons.- The orbital has various radius form the nucleus.


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e) Sir James Chadwick

- Discovered neutrons which are located in the nucleus.

- The neutral particle has the same mass as protons.

2. Atomic Structure Made up of subatomic particles; protons, electrons and neutron. Nucleus situated at the centre of atom.

has positive charge, protons. Neutrons may also present.

Electrically neutral. (Number of proton = Number of electrons) Have electrons which move around the nucleus in its shells.

Mass of proton = mass of neutron Nucleus contributes a lot of mass in an atom.

Subatomicparticles

Symbol Relative atomicmass (RAM)

Charge

Proton p 1 +

Neutron n 1 neutral

Electron e

3. Electron Configuration Maximum number for each shell: First shell : 2 electrons Second shell : 8 electrons Third shell : 8 electrons Forth shell : 2 electrons

Valence electron = electrons found in the outermost shell of an atom.


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4. Atomic number & Mass number Atomic number = proton number Nucleon number = proton number + number of neutrons Mass number = Nucleon number

2.3 KINETIC THEORY OF MATTER

1. According to the Kinetic Theory Of Matter, Matter consists of tiny and discrete particles. Particles always move randomly. There are forces of attraction between the particles.

Particles gain kinetic energy and move faster when heated. Particles lose kinetic energy and move slower when cooled. Can be proven by using 2 experiments: Diffusion and Brownian

movement.

2. Diffusion Occurs when particles of a substance move in between the particles of

another substance.

Random movement of particles from a high concentration region to alower concentration region.

Happens in three states of matter; solid, liquid and gas. Occurs most rapidly in gases, followed by liquid and solid. Particles diffuse from one medium to another. Rate of diffusion increases with the temperature. Rate of diffusion decreases when the mass of matter increases. Diffusion in gases:


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Diffusion of liquid:

(Blue)

Diffusion of solid:

3. Brownian movement

Random movement that is shown when colliding with other particle. Can only be observed under a light microscope. Supports the Kinetic Theory Of Matter.

Jelly


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2.4 ISOTOPES

1. Atoms of same element with the same number of protons but differentnumber of neutrons.

IsotopesUses

Carbon-14 determination of age of carbon-containing artifacts as a biological tracer, for example, in studies of

photosynthesis

Oxygen-18 biological tracer, for example, in studies of photosynthesisSodium-24 Detect location of leaks in water pipes,

studies of body electrolytesMagnesium-

27 location of leaks in water pipes

Cobalt-60 cancer treatment as tumour cells tend to be moresusceptible to radiation than other cells

Krypton-81 lung ventilation studies

Technetium-

99 Medical tracer used to locate brain tumours and problems

with the lungs, thyroid, liver, spleen, kidney, gall bladder,

skeleton, blood pool, bone marrow, salivary

to detect infectionIodine-131 Medical tracer

treat the thyroid gland &amp used in the diagnosis of adrenal medulla for imaging suspected neural crest and other endocrine

tumours

Iodine-123 used in imaging to monitor thyroid function detect adrenal dysfunction

Uranium-235 Enriched as a fuel for most nuclear reactors
http://www.ausetute.com.au/carbon14.htmlhttp://www.ausetute.com.au/carbon14.html


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Americium-

241 Domestic smoke alarms

Phosphorus-

32 Treatment of excess red blood cells
http://www.ausetute.com.au/smokedet.htmlhttp://www.ausetute.com.au/smokedet.htmlhttp://www.ausetute.com.au/smokedet.htmlhttp://www.ausetute.com.au/smokedet.html


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CHAPTER 3: CHEMICAL FORMULAE AND EQUATIONS

3.1 Formula and Chemical Equations

1.

Reasons of comparing relative atomic mass(R.A.M, Ar) with one carbon-12atom:

Solid and easily handled. Most abundant carbon isotope. Easily available. Used as a reference standard in spectrometer.

2. Formulae:

3.2 The Mole and the Volume of Gas

1. Avogadros Constant, NA Number of particles in one mole of substance. 6.02 10232. Standard Temperature and Pressure (S. T. P.) Temperature = 0C

MASS OFSUBSTANCE, g

NO. OF MOLES, mol

VOLUME OFSOLUTION, cm

3

NO. OF

PARTICLES, atoms

M.V.

M.V.

NA

NA

M.M. M.M.


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Pressure = 1 atmosphere / atm Molar volume of 1 mole of gas = 22.4dm3 or 22400cm33. Room condition (R. T. P.) Room temperature = 25C Pressure = 1 atmosphere / atm Molar volume of 1 mole of gas = 24dm3 or 24000cm3

3.3 Molecular Formula and Empirical Formula

1. Molecular formula: actual number of atoms in each element that presentin a molecule of the compound.

2. Empirical formula: simplest whole number ratio of atoms of each elementin the compound.

3. Empirical formula =

4. Example : GlucoseM.F.: C6H12O6E.F.: CH2O

5. Determining empirical formula by using table form:Element -

Mass/Percentage xNo. of mole y(

Ratio

Empirical formula

4. Experiment for empirical formula:For higher reactivity of metal (Mg, Zn, Ca, Al)

Metal tapeCrucible with lid


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Precaution:

- Lift the lid at intervals to allow oxygen gas to enter for

combustion of metal.

- Lid is closed immediately after it is lifted to prevent white fume

from escaping to the surroundings.

- Stop heating the metal when it is started to glow.

Reactive metal: both reactant and products are solid and thus, the

individual mass of metal and oxygen cannot be determined.

For lower reactivity of metal (Cu, Sn, Pb, Ag)

Chemical used to dry hydrogen gas: Anhydrous cobalt chloride /

anhydrous calcium chloride.

Hydrogen gas is flowed through the apparatus throughout the

experiment to prevent the air for entering it.


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CHAPTER 4: PERIODIC TABLE OF ELEMENTS

4.1 INTRODUCTION TO PERIODIC TABLE

1. Classifications of elements with the same chemical properties are placed inthe same group.

2. Elements in: Group 1Alkali metals Group 2Alkali earth metals Group 312transition elements Group 17Halogens Group 18Noble gases Group 1, 2, transition elements and 13metals Group 15, 16 and 17non metals Same groupsame chemical properties and valence electronsNo. ofvalence

electrons

1 2 3 4 5 6 7 8 / 2

Group 1 2 13 14 15 16 17 18

3. Historical Development of the Periodic Tablei. Antoine Lavoisier


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Classify elements into 4 groups which are gases, metals, non-metals andmetal oxide.

Not accurateheat and light are included as gases.ii. Johann W. Dobereiner Classify elements with the same chemical properties into groups of three

(triads).

Discover relationship between R.A.M. in each triad. (Middle R.A.M. =average R.A.M.)

iii. John Newlands Arrange elements in order of increasing nucleon number (mass number)

in horizontal rows. Each row has 7 elements.

Law of Octavesevery eighth element have similar chemical properties.Only accurate for the first 16 elements.

Discover the existence of periodic pattern.iv. Lothar Meyer Volume of an atom =

of an element

Graph of volume of atoms against their R.A.M. Show the properties of elements recur periodically.v. Dmitri Mendeleev Arrange element in order of increasing atomic mass. Left gaps for elements yet to be discovered.

vi.Henry G. J. Moseleyi. Different element with high energy electrons & measured the frequency of

the X-ray emitted by inert gases elements.

ii. Graph of square root of frequency against proton number.a) Group 18 elementsNoble GasesMade up of Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon

(Xe), Radon (Rn).

Exist in monoatomic form.Has stable electron arrangement (outermost shell filled with the maximum

number of electrons).

Chemically unreactive (do not share, donate or accept electrons).DupletHelium, Octetother noble gases.Physical properties:

Colourless gaseous state at room temperature.


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Low boiling and melting point (weak Van der Waals forces /intermolecular forces of attraction.

Do not conduct electricity. Low density (atoms are far apart). Going down the group,

Melting & Boiling point

Atomic size

Forces of attraction between atoms

Heat energy

Density

Atomic mass

Uses:Helium Fill airship, bicycle tyres of Olympic cyclist &

meteorological balloons.

Exist in the gas in divers oxygen tank.Neon Advertising boards / lights.

Electric discharge through glass tubes produces a redlight.

Argon Electric light bulb. Carrier gas in gas-liquid chromatography.

Krypton Laser light Flash lamps of a light house

Radon For cancer treatment.Xenon For flash lamp.

b) Group 1 elementsAlkali metals Made up of Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb),

Cesium (Cs), and Francium (Fr).

Has 1 valence electron. Very reactive to become positive ions (easily to donate valence electron). Physical properties: Soft metal with shiny and silvery surfaces (can be cut by knife). Good electric and heat conductor. Less dense than water.


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When going down the group,Melting and boiling point

Metallic bond

Forces of attraction

Atomic size

Density

Number of occupied shell

Chemical properties: Have same chemical properties. Electropositivity: measurement of ability of an element to lose an

electron and form a positive ion.

Good reducing agent. Can be oxidised easily. Going down the group, reactivity / electropositivity increases.

Safety precautions when handling Group 1 elements: Kept in paraffin oil. Use forceps to take them. Wear safety goggles & gloves.

Reactions:a) Alkali metal + water Hydroxide solution produced will turn red litmus paper red. Products: metal hydroxide + hydrogen gas

Lithium 2Li + 2H2O 2LiOH + H2

Moves slowly with hiss sound.

Sodium 2Na + 2H2O 2NaOH + H2Moves quickly and randomly with loud hiss sound.

Potassium 2K + 2H2O 2KOH + H2

Burns with reddish-purple light, jumps, hiss and pop sound.

Increases

Decreases

Alkali metal

Cold water


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b) Alkali metal + oxygen Products: metal oxide (white powder). When metal oxide dissolves in water, it turns phenolphthalein

indicator red (presence of OH-ionsalkaline)

Lithium 4Li + O2 2Li2O

Burns slowly with red light.

Sodium 4Na + O2 2Na2OBurns quickly and brightly with yellow light.

Potassium 4K + O2 2K

2O

Burns very quickly and brightly with reddish-purple light.

c) Alkali metal + halogen gas (Chlorine & Bromine) Products: metal halides (metal bromide / chloridewhite powder)

Halogen


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Lithium 2Li + Cl2 2LiCl / 2Li + Br2 2LiBr

Burns slowly with reddish flame. A white solid is obtained.

Sodium 2Na + Cl2 2NaCl / 2Na + Br2 2NaBr

Burns brightly with a yellowish flame. A white solid is obtained.

Potassium 2K + Cl2 2KCl / 2K + Br2 2KBrBurns very brightly with a purplish flame. A white solid is

obtained.

4.2 HALOGEN

1. Group 17 elements (Halogens) Made up of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and

astatine (At). Exist in diatomic molecules. Nonmetal. Physical properties: Heat and electrical insulator. Low melting and boiling point (weak forces between the molecules). When going down the group, Atomic size Van der Waals forces Heat energy used to overcome forces Boiling and melting point Colour of halogen darker.

2. Chemical properties: Same chemical properties (same valence electrons7) High electronegativity When going down the group, Reactivity/electronegativity Van der Waals forces Tendency to accept electron Solubility Atomic size Distance between the nucleus and outermost shell

Reaction: Halogen + water Product: two acids.


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Halogens act as bleaching agent, except iodine water. In general, X2 + H2O HX + HXO, where X is halogen. Chlorine water Turn blue litmus paper red then decolourise it. Prepared from the reaction between potassium manganate

(VII) chips with concentrated hydrochloric acid.

16HCl + 2KMnO4 2MnCl + 8H2O + 5Cl2

Chlorine (gas) Cl2 + H2O HCl + HClO Products: Hydrochloric acid + Hypochlorous acid

(bleaching agent).

Greenishyellow gas dissolves quickly to form a lightyellow solution.

Bromine (liquid) Br2 + H2O HBr + HBrO Products: Hydrobromic acid + hypobromous acid

(bleaching agent).

Reddishbrown liquid dissolves slowly, forming abrownishyellow solution.

Iodine (solid) I2 + H2O HI + HIO Products: Hydroiodic acid + hypoiodous acid (bleaching

agent).

Very little purplishblack solid dissolves, forming a lightyellow solution. Halogen + Sodium hydroxide solution, NaOH. Products: Sodium halide + Sodium halite(I) + Water In general, X2 + 2NaOH NaX + NaOX + H2O, where X is

halogen.

Chlorine Cl2 + 2NaOH NaCl + NaOCl(sodium chlorate) + H2O

Greenish-yellow gas dissolves quickly to form a colourless solution.

Bromine Br2 + 2NaOH NaBr + NaOBr(sodium bromate) + H2OReddish-brown liquid dissolve averagely to form a colourless

solution.

Iodine I2 + 2NaOH NaI+ NaOI(sodium Iodate) + H2O

Purplish-black solid dissolves slowly to form a colourless solution.

Halogen + Iron (Fe) Product: iron(III) halides (brown solid) Apparatus set up:


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Soda lime: mixture of calcium hydroxide and sodium hydroxide(absorb excess halogen gas)

Iron wool is heated strongly until red hot. Concentrated hydrochloric acid is added to potassium manganate

(VII) through a thistle funnel (to produce chlorine gas).

In general, 3X2 + 2Fe 2FeX3, where X is a halogen.Chlorine 3Cl2 + 2Fe 2FeCl3

Iron wool burns lights up strong and bright. Brown solid is formed.

Bromine 3Br2 + 2Fe 2FeBr3Iron wool glows moderately bright and less vigorously. Brown solid

is formed.

Iodine 3I2 + 2Fe 2FeI3

Iron wool glows dimly and slowly. Brown solid is formed.

3. Precaution: Halogens are poisonous gas. Must be handled in fume chamber.

When handling halogens. Safety goggles and gloves must be used. Fluorine is a radioactive substance, astatine is radioactive.

/ Lime soda


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4.3 Elements in a Period

1. Period: horizontal row in the Periodic Table.2. There are 7 periods in the modern periodic table.3. When it goes across the period from left to right: Electronegativity Proton number Valence electronsNon-metallic propertiesNuclei attraction on valence electrons Atomic size Electropositivity Metallic properties (Metallicity)Element Na2O MgO Al2O3 SiO2 P4O10 SO2 Cl2O7

Characteristics Basic oxides

(Alkali)

Amphoteric

oxides

Acidic oxides

4. Amphoteric oxides: react with both acids and alkalis, have base and acidicproperties. (

acid,

alkali)

5. Sodium, Magnesium and Aluminium : Metal Strong metallic bonds High melting and boiling points High strength of metallic bond

6. Silicon High melting and boiling points Has strong covalent bond, forming a 3-dimensional gigantic network.

7. Uses of semi-metals/metalloids(element with properties intermediatebetween those of metals and non-metals)

Silicon and Germaniummakes diodes and transistor/switch Conductivity increases with temperature. Important in microelectronic industry

Decreases

Increases


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8. Transition Element Elements between Group 3 until Group 12. Metals Show metallic properties: Shiny surface Ductile Malleable Can withstand high tension High melting and boiling point High density (big atomic mass despite small radius) Electric and heat conductor

Form coloured compounds or ionsTransition elements Colour

Chromium ion, Cr3+

Green

Iron(II) ion, Fe + Green

Iron(III) ion, Fe + Brown

Copper(II) ion, Cu2+

Blue

Chromate ion, CrO-4 Yellow

Manganese ion, Mn+ Pink

Cobalt ion, Co2+ PinkNickel ion, Ni

2+ Green

Manganate ion, MnO2-

4 Purple

Dichromate ion, Cr2O2-

7 Orange

Act as catalyst to speed up the reaction. Iron, FeHaber process (producing ammonia, NH3). Platinum, PtOstwald process (producing nitric acid, HNO3).Nickel, Nimanufacture of margarine. Vanadium (V) oxide, V2O5 Contact process (producing sulphuric

acid, H2SO4).

Form complex ions. Polyatomic anion/cation consisting of more than 2 metal ions with

other group bonded to it.

Exampleshexacyanoferrate (II)[Fe(CN)6]4-Tetramine copper (II)[Cu(NH3)4]

2+


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Have different oxidation number. Iron, Fe - +2, +3, +1 Manganese - +1, +2, +3, +6, +7 Nickel - +2, +3 Chromium - +2, +3, +6

Give colour to precious stone. Presence of ions in a solution can be confirmed by using sodium

hydroxide solution, NaOH / ammonia solution, NH3.

The ions of transition elements will react with hydroxide ion, OH - toform coloured solution / precipitate.

Precious stone Colour Transition elements

Emerald Green Nickel, IronRuby Red Chromium

Sapphire Blue Iron, Titanium

Amethyst Purple Iron, Manganese


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CHAPTER 5: CHEMICAL BONDS

5.1 Formation of Chemical Bonds

1.

Ionic bond Metal element reacts with non-metal element. Metal element (Group 1, 2, and 13) Non-metal element (Group 16 and 17) Metal elements donate electrons and produce positive ions. Non-metal elements will accept electrons to achieve a stable electron

configuration and produce negative ions.

These ions will attract each other by a strong electrostatic force ofattraction (ionic bond).

Examples: sodium chloride, magnesium oxide, lithium oxide.Elements which are reacting Formula of ionic

compoundMetal M Non-metal X

Group 1, M+

Group 15, M3-

M3X

Group 1, M+ Group 16, M - M2X

Group 1, M+

Group 17, M-

MX

Group 2, M + Group 15, M - M3X2

Group 2, M+

Group 16, M-

MXGroup 2, M2+ Group 17, M- MX2

Group 13, M3+

Group 15, M3-

MX

Group 13, M+

Group 16, M-

M2X3

Group 13, M + Group 17, M- MX3

Sodium chloride, NaCl


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4.2 Covalent Bonds

1. Formed by non-metal elements form Group 14, 15, 16, and 17.2. Atoms of non-metals will combine to donate one, two or three valence

electrons to be shared.3. 3 types of covalent bonds: Singlesharing one pair of electrons Doublesharing two pair of electrons Triplesharing three pair of electrons

4. These will form covalent compound.5. Examples:

Chlorine molecule, Cl2 (Single)

Water molecule, H2O (Single)

Carbon dioxide molecule, CO2 (Double)

Nitrogen molecule, N2 (Triple)


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Non-metal elements which combined Molecular

FormulaElement P Element Q

Group 14, P+

Group 17, Q-

PQ4

Group 14, P + Group 16, Q - P2Q4 / PQ2

Group 15, P+

Group 17, Q-

PQ3Group 16, P2+ Group 17, Q- PQ2

6. Physical properties of ionic compounds: High melting and boiling point Conducts electricity

Soluble in water, insoluble in organic solvents Able to ionize in water. Has strong electrostatic force of attraction Need a lot of heat energy to overcome the forces Arranged in lattice structure in solid state Contain free-moving ions that carry charges

7. Physical properties of covalent compounds: Low melting and boiling points Has weak Van der Waals forcesless heat energy is needed. Insoluble in water, soluble in organic solvent Cannot conduct electricity Do not contain free-moving ions that carry charges


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8. Giant molecules covalent compounds: Strong covalent bonds combine all atoms in a three-dimensional lattice

structure.

Have high melting and boiling point Unable to conduct electricity. Examples: silicon, graphite, silicon oxide, diamond, protein

9. Covalent compound as organic solvents Water

Dissolves all types of foodsugar and salt Dissolves food substances in the body Cleanses or gets rid of dirt

Organic solvent Ethanolpreparation of shellac, lacquer, paint, cosmetic and

perfumes

Petrol / kerosenecleans greasy and oily dirt stains Propanonenail varnish Chlorofluorocarboncleans circuit board of computer

5.4 Comparisons between ionic and covalent bond

Ionic compound Properties Covalent compoundNaCl, MgO, ZnCl2, CuO Examples O2, CO2, H2O, N2, Cl2

High has strong

electrostatic forces ofattraction (A lot of heat

energy is needed)

Melting and boiling

points

Low has weak

intermolecular forces ofattraction (Little heat is

needed)

Soluble in water,

insoluble in organicsolvent.

Solubility Soluble in organic

solvent, insoluble inwater.

Conduct electricity inboth molten and aqueousstate contain free

moving charged ions.

Electrical conductivity Do not conductelectricity.

Nonvolatile Volatility Volatile


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Ionic compound Covalent compound Metal

Simple Giant

Examples Cu, Zn, Na,

Ca, Pt, Ni,

MgM/P & B/P High Low High High

Solubility Soluble in

water, insoluble

in organic

solvents

Insoluble in

organic

solvent,

soluble in

water

Insoluble in

both

Insoluble in

both

Electrical

conductivity

Conduct in

molten state or

aqueoussolution

Does not Does not Conduct in

solid or liquid

Volatility No Yes No No


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CHAPTER 6: ELECTROCHEMISTRY

6.1 Electrochemistry

1.

Electrochemistry: study of the interconversion of chemical energy andelectrical energy.

2. Electrolyte: chemical substances that can conduct electricity in molten oraqueous form.

Examples:

Molten potassium iodide, KI Molten lead(II) chloride, PbCl2 Molten aluminium oxide, Al2O3 Sulphuric acid solution, H2SO4 Copper sulphate solution, CuSO4 Sodium chloride solution, NaCl

3.Non-electrolyte: chemical substances that cannot conduct electricity either inmolten or aqueous form as they have no free-moving ions.

Examples:

Sulphur Wood Molten sugar Naphthalene Covalent compounds except ammonia and hydrogen chloride

4. Conductor: substances that can conduct electricity in liquid or solid state (notregarded as electrolyte as they are not decomposed)

Copper Iron Platinum Silver

5. Electrolysis: process whereby a compound is separated into its constituentelements when an electric current passes through an electrolyte.

Electrical energy chemical energy


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Set up of apparatus:

Electrolysis of molten compound Electrolysis of aqueous solution

6. 2 types of electrodes:a) Active electrode- do not react with electrolytes

- do not involve in chemical reactions

- Carbon, platinum and graphite electrodes

b) Inert electrode- react with electrolytes

- involves in chemical reactions

- Copper, silver, or mercury electrodes7. Anode: electrode that connect to the positive terminal of battery.8. Cathode: electrode that connect to the negative terminal of battery.9. Anion: negatively charged ions and attracted to anode.10.Cation: positively charged ions and attracted to cathode.11.Half equation:

Positive ions (Cations) Negative ions (Anions)

K+

+ e K 2F-- 2e F2

2F- F2 + 2eNa

+ + e Na

Ca+

+ 2e Ca 2Cl- Cl2 + 2e

Mg + + 2eMg 2I- I2 + 2e

Al3+

+ 3e Al 4OH- 2H2O + O2 + 4e

Zn2+ + 2e Zn 2O2- O2 + 4e

Fe2+

+ 2e Fe 2Br- Br2 + 2e

Sn + + 2e Sn

Pb+

+ 2e Pb

2H+ + 2e H2

Cu

+

+ 2e

CuAg+

+ e Ag


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12.Electrolysis of molten compoundsMetal Observation

Sodium Shiny grey solid is formed.

Lead Shiny grey solid is deposited.Nickel Shiny grey solid is formed.

Copper Brown deposit is formed.

Gas Observation

Bromine Brown gas is produced. (pungent smell)

Iodine Purple gas is produced.

Chlorine Yellowish-green gas is produced.

Oxygen Colourless gas bubbles are formed. (effervescence)

Hydrogen Colourless gas bubbles are formed. (effervescence)

6.2 Electrolysis of Aqueous Solution

1. Aqueous solution: Produced when solute is dissolved in water. Electrolyte containing cations, anions, H+ and OH- ions.

2. During electrolysis of aqueous solution: 2 cations are attracted to cathode (-). 2 anions are attracted to anode (+). Only one of the four ions will be chosen to be discharged at anode and

cathode.

3. Factors affecting which ions are chosen to be discharged: Position of ions in the electrochemical series (ECS) Concentration of ions in the solution Type of electrodes used

Test for Oxygen gas, O2

A glowing splinter is placed near the

mouth of the test tube containing

oxygen gas. It will light up.

Test for Hydrogen gas, H2

A lighted splinter is placed near the

mouth of the test tube containing

oxygen gas. A pop sound is

produced.


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4. Position of ions in the electrochemical series (ECS)Cations Anions

K

NaCa

Mg

Al

Zn

Fe

Sn

Pb

H

Cu

Ag

Kalau

NakCari

Minum

Air

Zappel

Free

Sila

Pergi

Hotel

Curi

Agar

F-

SO42-

NO3-

Cl-

Br-

I-

OH-

Father

SayNothing

Can

Buy

Indian

Oranges

The lower the position of the ion, the higher the tendency of the ions to bedischarged.

Sulphate ion, SO42- and nitrate ion, NO3- cannot be discharged.5. Concentration of ions The anions in a lower concentration solution will be chosen to be

discharged. (diluted)

The cations in a higher concentration solution will be chosen to bedischarged.

Diluted 0.0001, 0.001, 0.01 dm-3 Concentrated0.1, 1.0, 2.0 dm-3 K+ and Na+ cannot be discharged even if their concentration of the

solution is high.

6. Types of electrodes used Inert electrodes: Carbon, graphite and platinum (Both of these electrodes

do not react with the electrolytes or products of electrolysis) Active electrodes: Silver, copper and nickel (Active anode ionises and

concentration of cations in the electrolyte does not change)

6.4 Application of Electrolysis

1. Electroplating of metals Objectives: to prevent corrosion / to improve appearance. Plating metals: gold (Au), Platinum (Pt), Chromium (Cr), copper (Cu),

Silver (Ag), & Nickel (Ni).


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Conditions: Object to be plated cathode Electroplating metal anode Electrolyte used must contain the metal ions. Surface of electroplating metal must be cleaned.

Set-up apparatus:

2. Extraction of metals Reactive metals (Na, Ca, Mg, Al) are extracted from their ores

compounds using electrolysis.

These metals cannot be extracted by reduction using carbon.a) Extraction of aluminium metal from bauxite (aluminium oxide)

Cryolite is added to bauxite to lower the temperature of bauxite from2000C to 950C.

Bauxite dissociates.Al2O3

2Al

3+

+ 3O

2-

Half equation at cathode : Al3+ +3e Al


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Half equation at anode : 2O2- O2 + 4e Overall equation : 4Al3+ + 6O2- 4Al + 3O2 Carbon electrodes react with the oxygen gas to produce carbon

dioxide.

Hall Heroults Process.b) Extraction of sodium metal from sodium chloride

Iron : cathode Carbon : anode Setup apparatus:

Calcium chloride is added to lower the melting point of sodiumchloride.

Half equation at cathode : Na+ + e Na Half equation at anode : 2Cl- Cl2 + 2e Overall equation : 2Na+ + 2Cl- 2Na + Cl2 Downs Process

3. Purification of metals Impure metal containing impurities can be purified. Conditions: Impure metal : anode Pure metal : cathode Electrolyte used must contain the metal ions.


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Set-up apparatus:

Observation: Copper anode becomes thinner and the impurities are deposited below

it.

Copper cathode becomes thicker. Intensity of blue solution remains the same. Rate of formation of

copper(II) ions of anode = rate of discharge of copper(II) ions of

cathode. Concentration remains the same.

Half equation at anode : Cu Cu2+ +2e Half equation at cathode : Cu2+ + 2e Cu

6.5 Voltaic Cell

1. Simple voltaic cell Uses two metal plates being immersed in an electrolyte (must contain

one of the metal ions).

Two different metals used must have different positions in theelectrochemical series.

Voltage can be measured by using voltmeter. The further the distance between those two metals in electrochemical

series, the higher the voltage produced.

Higher position of metal will donate electrons more easily to formpositive ion and become a negative terminal (anode).

Lower position of metal will accept electrons from the electrolyte toform metal and become a positive terminal (cathode).

This results in the thinning and thickening of the plates. Unstable and will decrease rapidly.


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2. Daniell cell Produces more stable cell voltage. Cell built with two pieces of different metal immersed in a salt solution

of their respective metals.

Porous pot: to complete the circuit by allowing the transition of ions andseparate both solutions.

Porous pot can be replaced by salt bridge. Salt bridge: consists of filter paper soaked with a concentrated salt

solution such as sodium chloride, potassium chloride, potassium nitrate,

ammonium chloride and dilute sulphuric acid.

Weaknesses: Electrolyte can spill out easily. Difficult to carry around. Voltage produced decreases quickly due to the polarity of the

cell(formation of gas bubbles around the electrodes)


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3. Examples of voltaic cells:


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4. Advantages and disadvantages of voltaic cells:

5. Comparison between electrolytic cell and voltaic cell:


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6.6 Construction of Electrochemical Series through Cell Potential

Difference

1. Procedure: 30cm3 of 1 moldm-3 copper(II) sulphate solution is added into a beaker. A piece of magnesium tape and copper metal are cleansed with sand

paper and immersed into copper(II) sulphate solution.

Both pieces of metals are connected to a voltmeter using wires as shownin the diagram.

The voltmeter reading is recorded. The positive and negative terminalsare determined.

The procedure is repeated by using zinc, iron, lead, aluminium andcopper metal.

2. More electropositive metal : negative terminal3. The further apart two metals are in the ECS, the higher the voltage of the

cell.

6.7 Construction of Electrochemical Series through Displacement

Reaction

1.

Metal which is more electropositive (placed higher) in the ECS will displaceother metals less electropositive (below it) from its salt solutions.

2. Summary:Solution

Metal

Copper(II)

salts

(Cu2+

)

Lead(II)

salts

(Pb2+

)

Iron(II)

salts

(Fe2+

)

Zinc salts

(Zn2+

)

Magnesium

salts

(Mg2+

)

Copper ~ No No No No

Lead Yes ~ No No No

Iron Yes Yes ~ No NoZinc Yes Yes Yes ~ No

Magnesium Yes Yes Yes yes ~


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Chapter 7: Acids and Bases

7.1 Acids and Bases

1.

Acid Chemical substance that dissociate in water to produce hydrogen ions, H+

or hydroxonium ions, H3O+.

Depicted as proton donors (H+). Strength of acid depends on the degree of dissociation/ionization. 3 types of acids: Monoprotic acid (HCl, HNO3) Diprotic acid (H2SO4) Triprotic acid (H3PO4)

Physical properties: Sour in taste pH value: less than 7 Turns blue litmus paper red. Conducts electricity (has free-moving ions).

Chemical properties: Acid + metal salt + hydrogen gas Hydrogen gas can be tested by using a glowing splinter. Less reactive metals (Pb and Cu) are not suitable for the reaction.

Acid + carbonate salt salt + water + CO2 gas CO2 gas turns lime water chalky/milky/cloudy.

Acid + alkali (base) salt + water Neutralisation reaction.

Non-organic/mineral acid (strong acid) Organic acid (weak acid)

a. Sulphuric acid, H2SO4b. Hydrochloric acid, HClc.Nitric acid, HNO3d. Carbonic acid, H2CO3e. Phosphoric acid, H3PO4f. Sulphurous acid, H2So3

a. Methanoic acid, HCOOHb. Ethanoic acid, CH3COOHc. Lactic acid (sour milk)d. Citric acid (citrus fruit)e. Ascorbic acid (vit. C)f. Ethanediodic acid, H2C2O4g. Formic acid (insect bites)


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Strong acid Weak acid

Dissociate completely intohydrogen ions in water.

Degree of dissociation is 100%. Produces higher concentration of

hydrogen ions and lower pHvalue.

Eg: Hydrochloric acid Sulphuric acid Nitric acid

Dissociate partially into hydrogenions in water.

Degree of dissociation is


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4. Alkali Chemical substance that dissociate in water to produce hydroxide ion,

OH-).

Have alkaline properties as the formation of freely moving hydroxideions in water.

Eg: Sodium hydroxide, NaOH Aqueous ammonia, NH3 Potassium hydroxide, KOH Calcium hydroxide, Ca(OH)2

Physical properties: Feel soapy when in touch Bitter in taste Turns red litmus paper blue Has a pH >7 Conducts electricity

Chemical properties: Acid + Alkali Salt + Water (neutralization) Alkali + ammonium salt salt + water + ammonia gas

5. Water and alkaline properties Alkaline properties only can be shown in the presence of H2O (presence

of free-moving ions).

Ionic compoundNaOH, KOH, Ca(OH)2 Cannot show their properties in organic solvent. Ionisation of alkali produces hydroxide ions in water.

Covalent compoundNH3 Can dissolve in both water and organic solvent (trichloromethane). Only show its properties in water. Conduct electricity only in water. There is no mobile ion in organic solvents.


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7.2 The Strength of Acids and Alkalis

Strong alkali Weak acid

Dissociate completely intohydroxide ions in water.

Degree of dissociation is 100%. Produces higher concentration of

hydrogen ions and higher pH

value (pH 14).

Eg: Sodium hydroxide, NaOH Potassium hydroxide, KOH

Dissociate partially into hydrogenions in water.

Degree of dissociation is


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3. Concentration / molarity No. of moles =

/

1000cm3 = 1dm3 Concentration = /

4. Standard solution: solution which has a known concentration. Prepared by using volumetric flask. Dilution method:

7.4 Neutralisation

1.Neutralisation

Titration method

Reaction between an acid and a base to produce salt and water. Acid + Base Salt + Water H+ ions from acid will react with OH- ions from the alkali to produce

water molecules.

H+ + OH- H2O (ionic equation)

Neutral solution produced pH 7. Titration: method used to determine the molarity of a solution by using

another solution with a known molarity.


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End point: all the ions dissociated from acid and alkalis have reactedcompletely to form water molecules. (neutral, pH 7)

The water molecules dissociated into ions and thus do not conductelectricity.

Formula:

=

(ratio of acid and alkali)

Graph:


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CHAPTER 8: SALTS

8.1 Salts

1. Salts

Ionic compound that is formed when H

+

ions in an acid is replaced by ametal ion or ammonium ion.

Neutral [ pH 7phenolphthalein (colourless)] Neutral in term of electrical charges. Can be produced through neutralisation process. Examples:

Acids

Hydrochloric acid HCl X chloride

Nitric acid HNO3 X nitrateSulphuric acid H2SO4 X sulphate

Carbonic acid HCO3 X carbonate

Phosphoric acid H2PO4 X phosphate

Ethanoic acid CH3COOH X ethanoate

2. Solubility of saltsType of salts Solubility in water

Sodium, potassium & ammonium

salts

All are soluble except oxide,

hydroxide and carbonate

Nitrate, ethanoate salts All are solubleChloride salts All are soluble except PbCl2, AgCl,

HgCl2

Sulphate salts All are soluble exceptPbSO4,BaSO4,

CaSO4

Carbonate, oxide & hydroxide salts All are insoluble except sodium,

potassium & ammonium

Lead(II) salts All are insoluble except Pb(NO3)2

andPb(CH3COO)2

***Lead hallides such as lead(II) chloride, lead(II) bromide and lead(II)iodide are insoluble in cold water but soluble in hot water.

***Lead(II) nitrate is soluble in both cold and hot water.

3. Preparation of soluble salts except soluble salts of sodium, ammonium andpotassium

Acid + alkali salt + water Acid + metal salt + hydrogen Acid + base salt + water Acid + metal carbonate salt + water + carbon dioxide


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4. Preparation of soluble salts of sodium, ammonium and potassiumi. Titration of an acid and alkali (Neutralisation)

ii. Crystallization (Heating)iii. Recrystallization (Filtration)

5. Crystals Formed when a saturated salt solution is cooled down. Physical characteristics:

Fixed geometrical shape Flat surfaces, straight edges and sharp corners Fixed angle between two adjacent surfaces Hard and brittle

Colour of crystal depends on the ions in the crystals.Salt / metal oxide Colour

Solid Aqueous solution

Copper(II) salts

Copper(II) carbonate

Copper(II) sulphate, copper(II)

nitrate, copper(II) chloride

Copper(II) oxide

Green

Blue

Black

Insoluble

Blue

Insoluble

Iron(II) salts

Iron(II) sulphate, Iron(II)

nitrate, Iron(II) chloride

Light green Light green

Iron(III) salts


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Iron(III) sulphate, Iron(III)

nitrate, Iron(III) chloride

Brown Brown /

Greenbrownish

Zinc oxide Yellow (hot)

White (cold)

Insoluble

Lead(II) oxide Brown (hot)Yellow (cold)

Insoluble

Magnesium oxide, aluminium

oxide

White Insoluble

Potassium oxide, sodium oxide,

calcium oxide

White Colourless

6.

8.2 Qualitative Analysis of Salts


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1. Test for gases:Gases Colour Smell Effect on damp

litmus paper

Confirmation

test

Oxygen, O2 Colourless - - Light up

glowing splinterHydrogen, H2 Colourless - - Lighted splinter

is placed near

the mouth of the

test tube. A

pop sound is

produced.

Carbon

dioxide, CO2

Colourless - Damp blue litmus

paper turns red

Bubbled through

lime water. It

will turn milky.Ammonia,

NH3

Colourless Pungent Damp red litmus

paper turns blue

Forms dense

white fumes

with hydrogen

chloride gas.

Chlorine, Cl2 Greenish

yellow

Pungent Damp blue litmus

paper turns red,

then decolourises

/ bleaches it.

Tested by using

litmus paper.

Hydrogenchloride, HCl Colourless Pungent Damp blue litmuspaper turns red Forms densewhite fumes

with ammonia.

Sulphur

dioxide, SO2

Colourless Pungent Damp blue litmus

paper turns red

Decolourise

purple colour of

potassium

manganate(VII)solution /

changes orange

potassium

dichromate(VI)

solution

Nitrogen

dioxide, NO2

Brown Pungent Damp blue litmus

paper turns red

Tested by using

litmus paper.

2. Production of gases:Gases Production


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Oxygen, O2 Heating a chlorate(V) or nitrate salt

Hydrogen, H2 Acid-metal reaction

Carbon dioxide, CO2 Heating a metal carbonate or acid-carbonate reaction

Ammonia, NH3 Heating a mixture of ammonium salt and alkali

Chlorine, Cl2 Heating a mixture of manganese(IV) oxide andconcentrated hydrochloric acid

Hydrogen chloride, HCl Heating a common salt and concentrated sulphuric

acid

Sulphur dioxide, SO2 An acid-sulphite reaction

Nitrogen dioxide, NO2 Heating a nitrate salt

3. Action of heat on salts Carbonate salts


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Nitrate salts

Sulphate saltsi. Group 1 and 2 sulphate salts do not decompose when heated.

ii. The sulphates of heavy metals decompose into metal oxides andsulphur trioxide when heated except iron(II) sulphate which

release sulphur dioxide gas.

iii. Ammonium sulphate sublimates at first and decompose intoammonia and hydrogen sulphate when further heating.


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Chloride saltsi. All are stable to heat except ammonium chloride.

ii. Ammonia gas emerges first, then followed by hydrogen chloride.4. Test for anions


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5.

Confirmatory tests


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6. Tests for cations


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CHAPTER 9: MANUFACTURED SUBSTANCES IN

INDUSTRY

9.1 Sulphuric Acid

1. Uses: To manufacture fertilizers To manufacture detergent To manufacture pesticides To manufacture synthetic fibres (boat, wall) To manufacture paint To manufacture metal oxide As an electrolyte (lead-acid accumulator)

2. Contact process

Sulphur, SSulphur

dioxide, SO2Sulphur

trioxide, SO3

Oleum, H2S2O7Sulphuric acid,

H2SO4

Step I Step II

Step III

Catalyst: Vanadium(V) oxide

Temperature: 450C - 550C

Pressure: one atmosphere (atm)


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Step Ii. Production of sulphur dioxide

ii. S + O2 SO2

Step IIi. Production of sulphur trioxide

ii. 2SO2 + O2 2SO3iii. High % of SO2 is converted into SO3.

Step IIIi. SO3 + H2SO4(concentrated) H2S2O7 (oleum)

ii. H2S2O7 + H2O 2 H2SO49.2 Ammonia

1. Main uses: To manufacture fertilizers As a cooling agent in refrigerator To produce nitric acid (Ostwald process) To make explosives To prevent coagulation of latex To produce ammonium chloride

2. Haber process+Nitrogen, N2 Hydrogen, H2

Ammonia, NH3

Excess N2 and H2


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3.Nitrogen gas is obtained from fractional distillation of liquid air.4. Source of hydrogen gas: Reaction between steam and heated coke (carbon) Reaction between steam and natural gas (methane)

5. Equation: N2 + 3H2 2NH36. Ratio of nitrogen gas to hydrogen gas 1 : 39.3 Alloy

1. Advantages of alloying: Increase the hardness/strength of metal Prevent corrosion/rusting Improve appearance of metal

2. Physical properties: Ductilecan slide over when external force is applied.

Catalyst: Iron powder

Promoter: Aluminium oxide

Temperature: 450550Pressure: 200500 atm


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Malleableslide into new positions in the empty spaces of alloy. High boiling and melting points High density Good conductor of electricity

Alloy Composition Properties Uses

Carbon steel 99% iron

1% carbon

Hard For construction,

bridges, vehicles,tools, heavy machinery

Stainless steel 74% iron

18% chromium

8% nickel

Rust resistant For crockery,

kitchenware and

machine parts

Bronze 90% copper

10% tin

Hard & shiny For kitchenware, ship

propellers, decorativeornaments and art

crafts.

Brass 70% copper

30% zinc

Hard & shiny For musical

instrument, electrical

connecter, decorativeornaments

Magnalium 70% aluminium

30% magnesium

Light & hard

Duralumin 95% aluminium1% magnesium

4% copper

Light & hard

Pewter 97% tin

3% lead and

antimony

Hard & shiny For mugs,

candlesticks,

decorative ornaments

and souvenirs.

Solder 50% tin

50% lead

Hard, shiny and

low melting point

For soldering electrical

wires and metal pipes

Cupro-nickel Copper, nickel Hard, shiny andcorrosion resistant

For coins

9.4 Synthetic Polymers

1. Polymers: large long-chain molecules formed by joining together manyidentical repeating sub-units called monomer.

2. Polymerisation: chemical process by which the monomers are joinedtogether into chain-like molecule called polymer.

3.Natural polymer: polymer obtained from animals and plants.


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4. Advantages of synthetic polymers Strong and light Cheap Able to resist corrosion Inert to chemical reactions Easily moulded or shaped and be coloured Can be made to have special properties

Name(s) Monomer Properties Uses

Polyethylene

low density(LDPE)

ethylene

CH2=CH2

soft, waxy solid film wrap,

plastic bags

Polyethylene

high density

(HDPE)

ethylene

CH2=CH2

rigid, translucent

solid

electrical

insulation

bottles, toysPolypropylene

(PP) different

grades

propylene

CH2=CHCH3

atactic: soft, elastic

solid

isotactic: hard,

strong solid

similar to LDPE

carpet,

upholstery

Poly(vinyl

chloride)

(PVC)

vinyl chloride

CH2=CHCl

strong rigid solid pipes, siding,

flooring

Poly(vinylidene

chloride)(Saran A)

vinylidene

chlorideCH2=CCl2

dense, high-melting

solid

seat covers,

films

Polystyrene

(PS)

styrene

CH2=CHC6H5

hard, rigid, clear

solid

soluble in organic

solvents

toys, cabinets

packaging

(foamed)

Polyacrylonitrile

(PAN, Orlon,

Acrilan)

acrylonitrile

CH2=CHCN

high-melting solid

soluble in organic

solvents

rugs, blankets

clothing

Polytetrafluoroethylene

(PTFE, Teflon)

tetrafluoroethylene

CF2=CF2

resistant, smoothsolid

non-sticksurfaces

electricalinsulation

Poly(methyl

methacrylate)

(PMMA, Lucite,

Plexiglas)

methyl

methacrylate

CH2=C(CH3)CO

2CH3

hard, transparent

solid

lighting covers,

signs

skylights

Poly(vinyl acetate)

(PVAc)

vinyl acetate

CH2=CHOCOCH3

soft, sticky solid latex paints,

adhesives


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cis-Polyisoprene

natural rubber

isoprene

CH2=CH-

C(CH3)=CH2

soft, sticky solid requires

vulcanization

for practical use

Polychloroprene (c

is + trans)(Neoprene)

chloroprene

CH2=CH-CCl=CH2

tough, rubbery solid synthetic rubber

oil resistant

9.5 Glass and ceramics

1. Properties of both glass and ceramics: Main component: silica or silicon dioxide, SiO2 Hard but brittle Inert towards chemicals Insulator of heat and electricity withstand compression but not stretching Can be easily cleaned Low cost of production

2. Differences between glass and ceramics: Glasstransparent , ceramicopaque Glasscannot withstand high temperature, ceramicscan withstand

high temperature3.

Type of glass:


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4. Special purpose glass and ceramicsI. Photochromic glass

II. Conducting glass produced by adding tin(IV) oxide (conductelectricity) used to make LCD.III. Super conductor ceramics used to make light magnets, electrical

generators & electric motors

9.6 Composite Materials

1.New material produced from a complex mixture of two or more materialswith different physical properties.


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Chemistry Form 4 A+ Notes

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