Chemistry, Review - Answers University Level

Chemistry Review University Level PART A- MULTIPLE CHOICE 1. Which of the following best represents a decomposition reaction? a. b. c. d. element + element → compound compound + compound → compound element + compound → compound + element compound → element + element 2. A carbonate producing a metal oxide and carbon dioxide is considered a(n) a) decomposition reaction. c) single displacement reaction. b) synthesis reaction. d) double displacement reaction. 3. Which description is not indicative of a chemical reaction? a. Formation of a white precipitate when a clear colorless liquid mixes with another clear colorless liquid. b. The formation of bubbles when zinc is dipped into acid. c. A piece of paper is set on fire. d. Formation of bubbles when water is left to boi on the stove top. 4. Which statement best describes an exothermic reaction? a) b) c) d) A reaction in which energy is absorbed by the system. A reaction in which energy is released by the system. A reaction in which heat is released by the system. None of these apply. 5. The catalyst in a chemical reaction… a) speeds up a reaction. b) slows down a reaction.. c) is used up in the process. d) is a product of the reaction. 6. The total number of atoms found in 2Cu(NO3)2 is a) 7 b) 5 c) 9 d) 18 7. Which of the following is a metal oxide? a) MgO b) HCl c) CO d) KOH 8. An acid will have a pH value… a) < 7 b) >7 c) = 7 d) ≥ 7 9. The IUPAC name for H3PO4 (aq) is a) phosphoric acid. b) phosphorous acid. c) hydro phosphoric acid. d) hydro phosphorous acid. Part B- Chemical Equations. 1. Write the word equation for each of the following descriptions of a reaction. chemical a) Sodium reacts with tin (IV) nitrate to produce sodium nitrate and tin. Sodium + tin (IV) nitrate → sodium nitrate + tin b) Hydrogen peroxide quickly decomposes into water and oxygen gas when manganese oxide is added. MnO Hydrogen peroxide → dihydrogen monoxide + oxygen gas c) Nitrous acid is produced when dinitrogen trioxide reacts with water. Dinitrogen trioxide + water → nitrous acid d) Copper metal and aluminum chloride are produced when aluminum mixes with copper (I) chloride. Aluminum + copper (I) chloride → copper + aluminum chloride e) Copper metal burns to produce a deposit of copper (I) oxide. Copper + oxygen 2. → copper (I) oxide Write the balanced chemical equation for each of the following word a) sulphury dioxide + water → sulphureous acid SO2 + H2O → HSO3 b) sodium hydroxide + phosphoric acid→ sodium phosphate +water 3NaOH + H3PO4 → Na3PO4 + 3H2O c) sodium + aluminum oxide → aluminum + sodium oxide Na + Al2O3 → Al + Na2O equations: d) oxygen gas + hydrogen gas → water O2 + H2 → H2O e) potassium chloride + silver nitrate → potassium nitrate + silver chloride KCl + AgNO3 3. → KNO3 + AgCl Identify the type of reaction in Question #2. a) synthesis d) synthesis b) double displacement e) double displacement c) single displacement 4. Balance each of the following equations. a) __Pb (NO3 )2 + __(NH4)2S → ___PbS + 2NH4 NO3 b) __K + __H2O → __KOH + ___H2 c) 3Mg + 2H3PO4 → __Mg3(PO4)2 + 3H2 d) 2P + 3O2 → __P2O3 e) 2C2H2 + 5O2 → 4CO2 + 2H2O 5. Predict the products of the following reactions and balance the reaction. a) 4 K + O2 → 2K2O b) C3H8 + 5O2 → 3 CO2 + 4H2O c) NaCO3 • H2O + heat → NaCO3 + H2O d) BaSO4 + 2KF → K2SO4 + BaF2 e) Mg + 2HI → MgI2 + H2 6. Write a complete balanced chemical equation, including the states of each of the following reactions: matter, for a) Solutions of sodium sulphate and barium chloride react to form a precipitate of barium sulphate and sodium chloride in solution. Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq) b) Iron (II) bromide in solution and hydrogen sulphide gas are produced when solid iron (II) sulphide reacts with hydrobromic acid. FeS(s) + HBr(aq) → FeBr2(aq) + H2S(g) c) The combustion of liquid butane, C4H10 , produces water vapour and carbon dioxide. C4H10 (l) + O2(g) → H2O(g) + CO2(g) d) Solid magnesium will react with oxygen to form magnesium oxide. Mg(s) + O2(g) → MgO(s) e) Solid barium reacts with tin(II) nitrate solution producing solid tin and a barium nitrate solution. Ba(s) + Sn(NO3)2(aq) → Sn(s) + Ba(NO3)(aq) 7. Using the metal activity series, explain why zinc will react with hydrochloric copper will not react with the acid. acid but Zinc is more active than copper. Zinc will displace the hydrogen ion of hydrochloric acid whereas copper will remain as a solid because it won’t displace the hydrogen ion of the acid.