Types ofTypes ofREACTIONS + REACTIONS +

solubilitysolubility

Chemical Equations

• In a chemical equation the physical state can be represented by a letter; – Gas = g– Liquid = l– Solid = s– Vapour = v– Aqueous = aq

• A Catalyst is a substance that speeds up a reaction without being used up itself (they are shown by writing above the arrow)

Reaction Types• Combination/ synthesis R + S RS• Decomposition RS R + S• Single-replacement T + RS TS + R• Double-replacement RS + TU RU + TS

• Combustion C?H? + O2 CO2 + H2O

How to Write a Balanced Equation

1 Write a word equation that includes all reactants and products

2 Write the formulae for all substances involved (to make an unbalanced equation).

3 Balance the equation by putting numbers in front of symbols or formulae. Start with elements that occur in one place only on each side of the equation.

4 Add symbols for the physical states, (s), (l), (g), (aq).

1. Identify which type of reaction each of the following are;

a. SnF4 + H2SO4 Sn(SO4)2 + HF

b. Li+ + O2 Li2O

c. Al2O3 Al3+ + O2

d. C3H8 + O2 CO2 + H2O

e. BeSiO3 + Cl- BeCl2 + SiO32-

2. Balance each of the equations above

3. Balance the following equationsa. Li+ + SO4

2- Li2SO4

b. AlCl3 Al3+ + Cl2c. BeS + Cl- BeCl2 + S2-

d. FeF3 + H2SO4 Fe2(SO4)3 + HF

e. C3H6 + O2 CO2 + H2O

1. .a. Double replacement

b. Combination

c. Decomposition

d. Combustion

e. Single replacement

2. .a. SnF4 + 2H2SO4 Sn(SO4)2 +

4HF

b. 4Li+ + O2 2Li2O

c. 2Al2O3 4Al3+ + 3O2

d. C3H8 + 5O2 3CO2 + 4H2O

e. BeSiO3 + 2Cl- BeCl2 + SiO32-

3. .a. 2Li+ + SO4

2- Li2SO4

b. 2AlCl3 2Al3+ + 3Cl2c. BeS + 2Cl- BeCl2 + S2-

d. 2FeF3 + 3H2SO4 Fe2(SO4)3 + 6HF

e. 2C3H6 + 9O2 6CO2 + 6H2O

Solublity Rules (insoluble = formation of precipitate in solution)

• All compounds containing either the Na+, NH4+, K+, or

NO3- ion will dissolve in water

• Compounds containing the Cl-, Br- and I- ions are soluble (except when they contain Ag+, Pb2+ or Hg2+ ions)

• Compounds containing the SO42- ions are soluble (except

when they contain Ba2+, Pb2+ or Ca2+ ions)• Compounds containing CO3

2- and PO43- are insoluble

except when they contain Na+, NH4+ or K+ ions)

• Compounds containing OH- are insoluble (except when they contain Na+, NH4

+, or K+ ions)• Some compounds are slightly soluble; Ca(OH)2, PbCl2,

PbBr2, CaSO4 and Ag2SO4

Reactivity series of Metals

• A single replacement reaction will only happen if the free metal is more reactive than the bonded metal

Li, K, Ba, Ca, Na, Mg, Al, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, H2, Cu, Hg, Ag, Au (most least reactive)

• Eg. If T + RS TS + R, then T must be more reactive than R

1. Predict whether each of the following are soluble or not

a. BaSO4

b. PbCO3

c. AgCl2d. Ca(OH)2

e. AlPO4

f. NaBr

2. Predict whether the following reactions will occur

a. Li + H2SO4

b. Cr2+ + AlCl3

c. BaS + Ag2+ d. H2 + AuCO3

3. Complete and balance the equations in Q2

1. .a. Insoluble

b. Insoluble

c. Soluble

d. Slightly Soluble

e. Insoluble

f. Soluble

2. .a. Yes

b. No

c. No

d. Yes

3. .a. 2Li+ + H2SO4 Li2SO4 + H2

b. 3Cr2+ + 2AlCl3 No Reaction

c. BaS + Ag2+ No Reaction

d. H2 + AuCO3 H2CO3 + Au2+