Which equation most accurately represents synthesisreaction between lithium and oxygen?
a) Li(s) + O2(g) ? LiO2(s)
b) 2 LiO(s) ? 2Li(s) + O2(g)
c) Li(s) + O2(g) ? 2 Li3O(s)
d) Li(s) + O2(g) ? 2 Li2O (s)

Which of the following equation represents aprecipitation reaction?
a) BaCO3(s) ? BaO + CO2
b) CaO(s) + SiO2(s) ? CaSiO3
c) LiBr(aq) + AgNO3(aq) ? LiNO3 + AgBr
d) H2O(g) + CO(g) ? H2 + CO2

Which of the following statements about chemicalreactions is accurate?
a) A balanced chemical equation gives the correct proportions ofchemicals in a chemical reaction and
obeys the law of conservation of mass.
b) Evidence of a chemical reaction includes colour change,absorption of energy, and formation of a
precipitate.
c) During a chemical reaction, reactant atoms rearrange to formproducts.
d) all of the above

Which of the following is an example of an exothermicreaction?
a) a firework display
b) heat + CO2(g) ? C(s) + O2(g)

c) neutralization reactions

d) both (a) and (c)

What would you expect to happen when you mix a AgNO3solution with a Na2S solution?
a) There will be no reaction between these two chemicals
b) The Na+ions will combine with NO3-ions to make a precipitate,NaNO3(s)

c) The Ag+ ions will combine with the Na+ ions to make aprecipitate, NaAg(s)

d) The Ag+ions will combine with the S2-ions to make aprecipitate, Ag2S(s)

True or false:

1. A synthesis reaction always involves two or more simplesubstances forming a compound

2. Sulfur dioxide is an acidic oxide.