* Determine how many moles are in 435 grams of NaCl. Significant figures matter so make sure you...

*Determine how many moles are in 435 grams of NaCl. Significant figures matter so make sure you have the correct amount.

*Do Now…

Mr. BerlinLuskin Academy

*Chemical Reactions Test Review

*Objective

*Objective: I will be able to identify the difference between ionic and covalent bonds and determine which atoms will form these bonds.

LecturePLUS Timberlake 99

*New Vocabulary

*Molecule: Two or more atoms bonded together to form a compound.*Ionic bond: when atoms are attracted to each other due to

ionic states of the atom.*Covalent bond: when a bond is formed by sharing of

electrons between atoms.*Single Bond: Shares one pair of electrons in a covalent bond.*Double Bond: Shares two pairs of electrons in a covalent

bond.*Triple Bond: Shares three pairs of electrons in a covalent

bond.*Mole: The measurement of grams in a formula or atom.

(same as atomic mass. Also, 1 mole = 6.022 x 1023 atoms).*Chemical Formula: The correct expression for the number of

atoms in a compound.


*Ionic Compounds

Attraction between + ions (cations) and – ions (anions)

Electrons go from metals to nonmetals

electron transfer metal nonmetal ion+ ion–

Electrons lost = Electrons gain

*Formulas of Ionic Compounds

Formulas of ionic compounds are determined from the charges on the ions

atoms ions

–

Na + F : Na+ : F : NaF

sodium fluorine sodium fluoride formula

Charge balance: 1+ 1- = 0

*Writing a Formula Write the formula for the ionic compound that will form between Ba2+ and Cl.Solution:1. Balance charge with + and – ions 2. Write the positive ion of metal first, and the

negative ion Ba2+ Cl Cl3. Write the number of ions needed as

subscripts BaCl2

*Naming Binary Ionic Compounds

Contain 2 different elementsName the metal first, then the nonmetal as -ide.

Use name of a metal with a fixed chargeGroups 1, 2, 3and Ag, Zn, and Cd Examples:

NaCl sodium chlorideZnI2 zinc iodideAl2O3 aluminum oxide

*Solution

Complete the names of the following binary compounds:Na3N sodium nitride

KBr potassium bromide

Al2O3 aluminum oxide

MgS magnesium sulfide

Transition Metals

Many form 2 or more positive ions

1+ 2+ 1+ or 2+ 2+ or 3+

Ag+ Cd2+ Cu+, Cu2+ Fe2+, Fe3+

silver cadmium copper(I) ion

iron(II) ion ion ion copper (II) ion iron(III) ion

Zn2+ zinc ion

*Names of Variable Ions

Use a roman number after the name of a metal that forms two or more ions

Transition metals and the metals in groups 4A and 5A

FeCl3 (Fe3+) iron (III) chlorideCuCl (Cu+ ) copper (I) chlorideSnF4 (Sn4+) tin (IV) fluoridePbCl2 (Pb2+) lead (II) chloride

Fe2S3 (Fe3+) iron (III) sulfide

*Learning Check

Complete the names of the following binary compounds with variable metal ions:

FeBr2 iron (_____) bromide

Cu2O copper (_____) oxide

SnCl4 ___( IV ) ________________

Fe2O3 ________________________

CuS ________________________

*Solution

Complete the names of the following binary compounds with variable metal ions:

FeBr2 iron ( II ) bromide

Cu2O copper ( I ) oxide

SnCl4 tin (IV) chloride

Fe2O3 iron (III) oxide

CuS copper (II) sulfide


*Covalent Bonds

Formed between two nonmetals in 4, 5, 6, and 7

Nonmetals have high electronegativity values

Electrons are shared

single bond shares one pair electrons

double bond shares two pairs electrons

triple bond shares three pairs electrons


*Learning Check

Indicate whether a bond between the following would be 1) Ionic 2) covalent

____ A. sodium and oxygen____ B. nitrogen and oxygen

____ C. phosphorus and chlorine____ D. calcium and sulfur

____ E. chlorine and bromine


*Solution

Indicate whether a bond between the following would be 1) Ionic 2) covalent

1 A. sodium and oxygen2 B. nitrogen and oxygen

2 C. phosphorus and chlorine1 D. calcium and sulfur

2 E. chlorine and bromine

*Comparison of bondsCovalent Bonds

*Share electrons*Held together by actual sharing of the electrons*Low boiling/melting points*Do not dissolve in water*Not brittle*Not conductive

Ionic bonds

*Loss or gain electrons*Held together by +/- forces.*High boiling/melting points*Dissolve in water*Brittle compounds *Salts*conductive


*Diatomic Molecules

Gases that exist as diatomic moleculesare H2, F2, N2, O2, Cl2, Br2, and I2. These molecules just keep their original names.

octets

N + N N:::N Triple bond

Example: O2 is just oxygen


*Learning Check

Use the name of the element to name the following diatomic molecules.H2 hydrogenN2 nitrogen

Cl2 _______________

O2 _______________

I2 _______________


*Solution

Use the name of the element to name the following diatomic molecules.H2 hydrogenN2 nitrogen

Cl2 chlorine

O2 oxygen

I2 iodine


*Naming Binary Covalent Compounds

Two nonmetalsName each element End the last element in -ideAdd prefixes to show more than 1 atomPrefixesmon 1 penta 5di 2 hexa 6tri 3 hepta 7tetra 4 octa 8


*Learning Check

Fill in the blanks to complete the following names of covalent compounds.

CO carbon ______oxideCO2 carbon _______________PCl3 phosphorus

_______chlorideCCl4 carbon ________chlorideN2O _____nitrogen _____oxide


*Solution

CO carbon monoxideCO2 carbon dioxide

PCl3 phosphorus trichloride

CCl4 carbon tetrachloride

N2O dinitrogen monoxide


*Electronegativity

The attraction of an atom for electrons is called its electronegativity.

Fluorine has the greatest electronegativity.

The metals have low electronegativities.


*Bond Polarity: Nonpolar

Nonpolar covalent bond Electrons are shared between atoms with the same electronegativity values.

Difference = 0Examples: N2 Br2 O2


*Solution

A. P2O5 3) diphosphorus pentoxide

B. Cl2O7 1) dichlorine heptoxide

C. Cl2 1) chlorine


*Bond Polarity: Nonpolar

Nonpolar covalent bond Electrons are shared between atoms with the same electronegativity values.

Difference = 0Examples: N2 Br2 O2


*Bond Polarity: Polar

Polar covalent bondElectrons are shared between different nonmetal atoms Examples:O-Cl O-S N-Cl H2O


*Learning Check

Identify the type of bond between the following atoms A. K-N

1) nonpolar 2) polar 3) ionicB. N-O

1) nonpolar 2) polar 3) ionicC. Cl-Cl

1) nonpolar 2) polar 3) ionic


*Solution

A. K-N 3) ionic

B. N-O 2) polar

C. Cl-Cl 1) nonpolar


*Learning Check

Match each set with the correct name:A. Na2CO3 1) magnesium sulfite

MgSO3 2) magnesium sulfate

MgSO4 3) sodium carbonate

B. Ca(HCO3)2 1) calcium carbonate CaCO3 2) calcium phosphate Ca3(PO4)2 3) calcium bicarbonate


*Solution

A. Na2CO3 3) sodium carbonate MgSO3 1) magnesium

sulfite MgSO4 2) magnesium

sulfate

B. Ca(HCO3)2 3) calcium bicarbonate CaCO3 1) calcium carbonate Ca3(PO4)2 2) calcium phosphate


*Type of Reactions

Chemical reactions are classified into four general types

Combination Decomposition Single ReplacementDouble Replacement


*Combination (Synthesis)

Two or more elements or simple compounds combine to form (synthesize) one product

A + B AB2Mg + O2 2MgO2Na + Cl2 2NaClSO3 + H2O H2SO4


*Decomposition

One substance is broken down (split) into two or more simpler substances.

AB A + B2HgO 2Hg + O2

2KClO3 2KCl + 3 O2


*Learning Check R1

Classify the following reactions as 1) combination or 2) decomposition:

___A. H2 + Br2 2HBr

___B. Al2(CO3)3 Al2O3 + 3CO2

___C. 4 Al + 3C Al4C3


*Solution R1

Classify the following reactions as 1) combination or 2) decomposition:_1_A. H2 + Br2 2HBr_2_B. Al2(CO3)3 Al2O3 + 3CO2

_1_C. 4 Al + 3C Al4C3


*Single Replacement

One element takes the place of an element in a reacting compound.

A + BC AB + C

Zn + 2HCl ZnCl2 + H2

Fe + CuSO4 FeSO4 + Cu


*Double Replacement

Two elements in reactants take the place of each other

AB + CD AD + CBAgNO3 + NaCl AgCl +

NaNO3

ZnS + 2HCl ZnCl2 +H2S


*Learning Check R2

Classify the following reactions as 1) single replacement 2) double replacement

__A. 2Al + 3H2SO4 Al2(SO4)3 +

3H2

__B. Na2SO4 + 2AgNO3 Ag2SO4 +

2NaNO3

__C. 3C + Fe2O3 2Fe + 3CO


*Solution R2

Classify the following reactions as 1) single replacement 2) double replacement

1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2

2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3

1_C. 3C + Fe2O3 2Fe + 3CO


*Combustion

A reaction in which a compound (often carbon) reacts with oxygen

C + O2 CO2

CH4 + 2O2 CO2 + 2H2O

C3H8 + 5O2 3CO2 + 4H2OC6H12O6 + 6O2 6CO2 +

6H2O


*Oxidation and Reduction

¨Reactions that involve a loss or gain of electrons¨Occurs in many of the 4 types of reactions and combustion

¨Important in food metabolism, batteries, rusting of metals


*Requirements for Oxidization-Reduction

Electrons are transferred Two processes occurOxidation = Loss of electrons (LEO)

Zn Zn2+ + 2e-

Reduction = Gain of electrons (GER)Cu2+ + 2e- Cu


*Gain/Loss of Hydrogen

In organic and biological reactionsoxidation = Loss of Hreduction = Gain of H

LecturePLUS Timberlake 99 46

*Writing Mole Factors

4 Fe + 3 O2 2 Fe2O3 Fe and O2 4 mole Fe and 3 mole O2

3 mole O2 4 mole Fe

Fe and Fe2O3 4 mole Fe and 2 mole Fe2O3

2 mole Fe2O3 4 mole Fe

O2 and Fe2O3 3 mole O2 and 2 mole Fe2O3

2 mole Fe2O3 3 mole O2

LecturePLUS Timberlake 99 47*Learning Check S1

3 H2(g) + N2(g) 2 NH3(g)

A. A mole factor for H2 and N2 is1) 3 mole N2 2) 1 mole N2 3) 1 mole N2

1 mole H2 3 mole H2 2 mole H2

B. A mole factor for NH3 and H2 is1) 1 mole H2 2) 2 mole NH3 3) 3 mole N2

2 mole NH3 3 mole H2 2 mole NH3


*Solution S1

3 H2(g) + N2(g) 2 NH3(g)

A. A mole factor for H2 and N2 is2) 1 mole N2

3 mole H2

B. A mole factor for NH3 and H2 is

2) 2 mole NH3

3 mole H2


*Learning Check S2

4 Fe + 3 O2 2 Fe2O3

How many moles of Fe are needed to react with 12.0 mole of O2?

1) 3.00 mole Fe 2) 9.00 mole Fe3) 16.0 mole Fe


*Solution S2

4 Fe + 3 O2 2 Fe2O3

12.0 mole O2 x 4 mole Fe = 16.0 mole Fe

3 mole O2

*How to calculate formula mass

*Formula mass is the sum of the atomic mass weights of each element in a empirical formula. To calculate, simply add up the average atomic mass of each atom.*Example:*NaCl Na = 22.99 grams

* Cl = 35.45 grams*total 58.44 grams

*Example:*BeCl2 Be = 9.01 grams

* 2 x Cl = 70.90 grams*total 79.91 grams


*Mass of A Reaction

The reaction between H2 and O2 produces 13.1 g of water. How many grams of O2 reacted?Write the equationH2 (g) + O2 (g) H2O (g)

Balance the equation 2 H2 (g) + O2 (g) 2 H2O (g)


*Points to Remember

1. Read an equation in moles2. Convert given amount to moles

3. Use mole factor to give desired moles

4. Convert moles to gramsgrams (given) grams (desired)

moles (given) moles (desired)

* Determine how many moles are in 435 grams of NaCl. Significant figures matter so make sure you...

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