Basic Chemistry IIVladimíra Kvasnicová

ExerciseAdd names of the elements:

NNaKCaMgMnAgCdHgSb

nitrogensodiumpotassiumcalciummagnesiummanganesesilvercadmiummercuryantimony

The figure is found at http://www.corrosionsource.com/handbook/periodic/periodic_table.gif (September 2007)

Inorganic Compounds

Make groups of compounds:

Na2O, HCl, CO2, Na2O2, Ca(OH)2, KClO, HCN, HNO2,

H2S, H2O2, BaO2, PbO2, H2SO3, KOH, MgSO4, NaF,

NH4HCO3, HI, Al(OH)3, HIO4, CdS, MgO2, NaH2PO4

? oxides hydroxides peroxides acids salts

Inorganic Compounds

Make groups of compounds:

Na2O, HCl, CO2, Na2O2, Ca(OH)2, KClO, HCN, HNO2,

H2S, H2O2, BaO2, PbO2, H2SO3, KOH, MgSO4, NaF,

NH4HCO3, HI, Al(OH)3, HIO4, CdS, MgO2, NaH2PO4

? oxides hydroxides peroxides acids salts

Inorganic Compounds

Oxides anion: O-II

• acid-forming: nonmetal / oxygen use multiple prefixes (mono, di, tri,...)

• base-forming: metal / oxygen use sufixes –ous / -ic or (oxidation state)

• amphoteric

MnO2, N2O, BaO, CO, K2O, SO2, FeO, Cu2O, CaO

Inorganic Compounds

Peroxides anion: O2-2 O-I

• s1 elements (hydrogen and alkali metals): M2O2

• s2 elements (alkali earth metals): MO2

sodium peroxide magnesium peroxide

barium peroxide potassium peroxide

hydrogen peroxide lithium peroxide

Inorganic Compounds

Hydroxides anion: (OH)-1

• basic properties (pH > 7)• strong or weak hydroxides• metal / hydroxide anion

use sufixes –ous / -ic or (oxidation state)

• ammonium / hydroxide anion

NaOH, LiOH, NH4OH, Fe(OH)3, Cu(OH)2, Ca(OH)2

Inorganic Compounds

Acids cation: H+ (pH < 7)

1) oxygen free acids

hydro-...................-ic acid

HF, HCl, HBr, HI, H2S, HCN (in aqueous solutions)

anion: -ide

• monoprotic / diprotic acids

Inorganic Compounds

Acids cation: H+

2) oxoacids the highest oxidative state per-.....-ic acid

higher (or only) oxidative state -ic acid

lower oxidative state -ous acid

the lowest oxidative state hypo-...-ous acid

anion:

-ic acid → -ate

-ous acid → -ite

Inorganic Compounds

The most important oxoacids:

H2CO3 carbonic acid

H2SiO3 silicic acid

H2CrO4 chromic acid

H3BO3 boric acid

H3PO4 phosphoric acid

H2SO3 sulfurous acid

H2SO4 sulfuric acid

HNO2 nitrous acid

HNO3 nitric acid

→ carbonate→ silicate→ chromate → borate → phosphate→ sulfite → sulfate→ nitrite → nitrate

Inorganic Compounds

The most important oxoacids:

HClO hypochlorous acidHClO2 chlorous acid

HClO3 chloric acid

HClO4 perchloric acid

(or Br, I)HMnO4 permanganic acid

H2S2O2 thiosulfurous acid

H2S2O3 thiosulfuric acid

→ hypochlorite→ chlorite→ chlorate→ perchlorate

→ permanganate

→ thiosulfite→ thiosulfate

Keep in mind the rules:

1. names of compounds are derived from the names of cations, anions and polyatomic ions: cation anion (NaCl = sodium chloride)

2. all binary compounds end in –ide

CaO, H2O2, NaCl, HF(g), ZnS

3. binary compounds composed of two nonmetals: Greek prefixes SO2, N2O5, CO

Keep in mind the rules:

4. binary compounds composed of a metal ion with fixed or variable oxidation numbers and nonmetal ion: no Greek prefixes

a) -ous / -ic suffix systemb) Stock system (prefered)

CuCl2, CuCl, Fe2O3, FeO

Keep in mind the rules:

5. ternary compounds: hydrogen cation H+ (= acid) or metal cation (= salt or hydroxide)(fixed or variable oxidation number) and a polyatomic anion (e.g. SO4

2- or OH1-)

H2SO4 Na2SO4 NaOH

Total charge of a molecule = 0

Inorganic Nomenclature

Call the compounds:

Na2O, HCl, CO2, Na2O2, Ca(OH)2, KClO, HCN, HNO2,

H2S, H2O2, BaO2, PbO2, H2SO3, KOH, MgSO4, NaF,

NH4HCO3, HI, Al(OH)3, HIO4, CdS, MgO2, NaH2PO4

Chemical reactions= chemical changes

stoichiometry = the reactants combine in simple whole-number ratios (see stoichiometric coefficients: a, b, c, d)

a A + b B → c C + d D

• the single arrow (→) is used for an irreversible reaction

• double arrows () are used for reversible reactions

chemical equilibrium = a state of a reversible chemical reaction in which the concentrations of reactatnts and products are not changing with time

ie the rates of both the forward and back reactions are equal

Chemical reactions

equilibrium constant (K) describes the ratio of concentrations of products and reactants in the equilibrium

a A + b B c C + d D

K = [C]c [D]d / [A]a [B]b

• K is constant for given reaction and fixed temperature

• the definition of K is called Guldberg-Waage´s law(= law of chemical equilibrium)

Chemical reactions

• a chemical reaction is described by a chemical equation

• the equation is balanced if substance amount of each element is the same on both sides of a chemical equation each element must be balanced in the order:

metal – nonmetal – hydrogen - oxygen

Conservation law (Law of conservation of mass / energy)

= the total magnitude of mass (or energy or charge) remain unchanged even though there may be exchanges of that property between components of the system

(the sum of masses of reactants equalsto the sum of masses of products)

Chemical reactions

• NEUTRALIZATION = acid-base reactions

H2SO4 + 2 NaOH → Na2SO4 + 2 H2O

acid + base → salt + water

• PRECIPITATION

NaCl + AgNO3 → AgCl (s) + NaNO3

→ insoluble product = precipitate is formed

• REDOX reactions = oxidative-reduction reactions

→ oxidation states of elements are changed !!!

Chemical reactions

oxidative-reduction reactions = REDOX reactions

→ oxidation states of elements are changed !!!

• two changes:

one element is oxidized (its ox. state raises)

other element is reduced (its ox. state lowers)

2 HCl + Zn → ZnCl2 + H2

Zn0 → Zn+II zinc is oxidized (0 → +II)

H+I → H0 hydrogen is reduced (+I → 0)

Important terms:

• reactants / products

• stoichiometric coefficients

• substance amount

• relative atomic / molecular mass

• molar mass

• density

• concentration (molar, percent)

Exercise – add formulas

• sodium sulfite• potassium phosphate• ammonium hydrogen phosphate• lithium dihydrogen phosphate• calcium hydrogen carbonate• silver sulfide• zinc sulfate• potassium permanganate• sodium hypobromite• barium nitrate• hydrargyric chloride

Exercise – add formulas

• sodium tetraborate decahydrate• potassium aluminium sulfate• sodium aluminium sulfate dodecahydrate• ammonium carbonate• calcium sulfate hemihydrate (hemi = ½)

• zinc sulfate heptahydrate• potassium dichromate• potassium magnesium fluoride• ammonium magnesium phosphate• led(II) chloride fluoride• cupric biscarbonate difluoride (bis = twice)