Chapter 7 Chemical Reactions

Which of the following is evidence that a chemical reaction has occurred? 7.1 Formation of a precipitate Color change Emission of light Evolution of gas All of the above Answer: e

What is the coefficient for aluminum after the following equation is balanced? Al + O2 → Al2O3 7.4 1 2 3 4 6 Answer: d

What is the sum of the coefficients after the following equation is balanced? Al2O3 + H2SO4 → Al2(SO4)3 + H2O 7.5 4 6 12 8 10 Answer: d

When the following equation is balanced, what is the ratio of oxygen molecules to water molecules? C5H10 + O2 → CO2 + H2O 7.6 0.66 1.0 1.66 1.5 2.5 Answer: d

Which of the following compounds is INSOLUBLE in water? 7.8 Li2SO4 KOH CaCO3 NH4NO3 NaCl Answer: c

A substance dissolved in water that CANNOT conduct an electric current is called a 7.9 electrical compound. strong electrolyte. weak electrolyte. weak cation. Nonelectrolyte. Answer: e

Identify the solid product formed from the balanced reaction of silver nitrate and calcium chloride. 7.11 CaNO3 AgCl Ca(NO3)2 AgCl2 CaAg Answer: b

Identify the solid product formed from the balanced reaction of potassium nitrate and barium chloride. 7.12 KCl BaNO3 K2Cl Ba(NO3)2 No solid is formed Answer: e

Which of the following is a term in the complete ionic equation for the following reaction? LiOH(aq) + MgCl2(aq) → 7.14 Mg2+(aq) OH–(aq) Mg(OH)2(s) Two of the above All of the above Answer: e

What salt is formed from the neutralization reaction between perchloric acid and potassium hydroxide? 7.18 Water Sodium chloride Potassium perchlorate Potassium hydride Potassium chlorate Answer: c

When an acid reacts with a base, what product is typically formed? 7.19 Water Sodium chloride Oxygen Carbon dioxide Ammonium chloride Answer: a

Which gas is released from the reaction of calcium carbonate with nitric acid? 7.20 Ammonia Nitrogen dioxide Hydrogen Carbon dioxide Nitrogen Answer: d

How many molecules of carbon dioxide are produced from the combustion of one molecule of propane (C3H8)? 7.21 1 3 4 5 6 Answer: b

What type of reaction is the following? HgO (s) → Hg(l) + O2(g) 7.23 Synthesis/combination Decomposition Single displacement Double displacement Two of the above Answer: a

What type of reaction is the following? 4Fe(s) + O2(g) → 2Fe2O3(s) 7.24 Oxidation–reduction Combustion Synthesis All of the above Answer: d

What type of reaction is the following What type of reaction is the following? Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g) 7.25 Precipitation Acid–base Double displacement Single displacement Answer: d

When NaHSO3 reacts with HNO3, what product is formed? 7.26 Na2SO4 H2SO4 SO2 gas NaNO2 N2 gas Answer: c

When compounds containing carbon and hydrogen react with oxygen in combustion reactions what is/are produced? 7.30 CH4(g) and O2(g) H2(g) and O2(g) CO2(g) and H2O(g) C2H6(g) None of the above Answer: c