Unit 5 Practice Test. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Transcription

1 Name: Class: Date: Unit 5 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The internal energy of a system is always increased by. A) adding heat to the system B) having the system do work on the surroundings C) withdrawing heat from the system D) adding heat to the system and having the system do work on the surroundings E) a volume compression 2) A H corresponds to an process. A) negative, endothermic B) positive, exothermic C) positive, endothermic D) zero, exothermic E) zero, endothermic 3) A chemical reaction that releases heat to the surroundings is said to be and has a H at constant pressure. A) endothermic, positive B) endothermic, negative C) exothermic, negative D) exothermic, positive E) exothermic, neutral 4) Under what condition(s) is the enthalpy change of a process equal to the amount of heat transferred into or out of the system? (a) temperature is constant (b) pressure is constant (c) volume is constant A) a only B) b only C) c only D) a and b E) b and c 5) Of the following, H f is not zero for. A) O 2 (g) B) C (graphite) C) N 2 (g) D) F 2 (s) E) Cl 2 (g) 1

2 Name: 6) For the species in the reaction below, H f is zero for. 2Co (s) + H 2 (g) + 8PF 3 (g) 2HCo(PF 3 ) 4 (l) A) Co (s) B) H 2 (g) C) PF 3 (g) D) HCo(PF 3 ) 4 (l) E) both Co(s) and H 2 (g) 7) With reference to enthalpy changes, the term standard conditions means. (a) P = 1 atm (b) some common temperature, usually 298 K (c) V = 1 L A) a only B) b only C) c only D) a and c E) a and b 8) Calculate the kinetic energy in J of an electron moving at m/s. The mass of an electron is g. A) J B) J C) J D) J E) J 9) Calculate the kinetic energy in joules of an 80.0 g bullet traveling at m/s. A) J B) J C) J D) 12.0 J E) 80.0 J 10) The value of H for the reaction below is 72 kj. kj of heat are released when 80.9 grams of HBr is formed in this reaction. H 2 (g) + Br 2 (g) 2HBr (g) A) 144 B) 72 C) 0.44 D) 36 E) 72 2

3 Name: 11) The value of H for the reaction below is 482 kj. Calculate the heat (kj) released to the surroundings when 38.5 g of O 2 (g) reacts with excess CO. 2CO (g) + O 2 (g) 2CO 2 (g) A) kj B) 482 kj C) 580. kj D) 65.7 kj E) 210. kj 12) The value of H for the reaction below is 1107 kj: 2Ba (s) + O 2 (g) 2BaO (s) How many kj of heat are released when g of Ba (s) reacts completely with oxygen to form BaO (s)? A) 20.8 kj B) 63.5 kj C) 114 kj D) 70.3 kj E) 35.1 kj 13) Given the following reactions N 2 (g) + O 2 (g) 2NO (g) 2NO (g) + O 2 (g) 2NO 2 (g) H = kj H = kj the enthalpy of reaction for is kj. A) 67.6 B) 45.5 C) D) 45.5 E) NO (g) 2NO 2 (g) + N 2 (g) 3

4 Name: 14) Given the data in the table below, H rxn for the reaction is kj. C 2 H 5 OH (l) + O 2 (g) CH 3 CO 2 H (l) + H 2 O (l) A) 79.0 B) C) D) E) The value of H f of O 2 (g) is required for the calculation. 15) Given the data in the table below, H rxn for the reaction is kj. SO 3 (g) + H 2 O (l) H 2 SO 4 (l) A) 132 B) 1496 C) 704 D) 704 E) ) The kinetic energy of a 26.9-g object moving at a speed of 81.9 m/s is J. A) 145 B) C) 90.2 D) E)

5 Name: 17) At what velocity (m/s) must a 19.9 g object be moving in order to possess a kinetic energy of 1.0 J? A) 0.35 m/s B) 2.8 m/s C) 0.13 m/s D) m/s E) m/s 18) The value of ΔE for a system that performs 151 kj of work on its surroundings and loses 79 kj of heat is kj. A) B) 230. C) +72 D) 72 E) ) The temperature of a 11.8 g sample of calcium carbonate [CaCO 3 (s)] increases from 24.8 C to 38.0 C. If the specific heat of calcium carbonate is 0.82 J/g-K, how many joules of heat are absorbed? A) 130 J B) 0.92 J C) 130 J D) 0.92 J E) 11 J 20) A 22.9 g sample of iron absorbs 155 J of heat, upon which the temperature of the sample increases from 23.9 C to 38.9 C. What is the specific heat of iron? A) J/g-K B) J/g-K C) 237 J/g-K D) 102 J/g-K E) 53,200 J/g-K 21) The H for the solution process when solid sodium hydroxide dissolves in water is 44.4 kj/mol. When a 12.6-g sample of NaOH dissolves in g of water in a coffee-cup calorimeter, the temperature increases from 23.0 C to C. Assume that the solution has the same specific heat as liquid water, i.e., 4.18 J/g-K. A) 35.2 B) 24.0 C) 36.4 D) 35.7 E) 40.2 Short Answer 1) is defined as the energy used to move an object against a force. 5

6 Name: 2) Given the equation H 2 O (l) H 2 O (g) Hrxn = 40.7 kj at 100 C Calculate the mass of liquid water (in grams) at 100 C that can converted to vapor by absorbing 2400 J of heat. 3) Given the equation H 2 O (l) H 2 O (g) Hrxn = 40.7 kj at 100 C Calculate the heat required to convert 3.00 grams of liquid water at 100 C to vapor. 4) When grams of NaOH is dissolved in grams of water, the temperature of the solution increases from C to C. The amount of heat absorbed by the water is J. (The specific heat of water is 4.18 J/g- C.) 5) Given the equation: CH 4 (g) + 2 O 2 (g) CO 2 (g) + H 2 O (l) H = kj The heat liberated when grams of methane (CH 4 ) are burned in an excess amount of oxygen is kj. 6) The standard enthalpy change of a reaction is the enthalpy change when all reactants and products are at pressure and a specific temperature. 7) Coal contains hydrocarbons of high molecular weight as well as compounds containing, oxygen, or nitrogen. True/False Indicate whether the statement is true or false. 1) Work equals force times distance. 2) One joule equals 1 kg-m 2 /s 2. 3) Units of energy include newtons, joules, and calories. 4) The primary component of natural gas is propane. 5) Renewable energy sources are essentially inexhaustible. 6) Petroleum is a liquid composed of hundreds of compounds. 6

7 Unit 5 Practice Test Answer Section MULTIPLE CHOICE 1) ANS: A PTS: 1 DIF: 2 REF: Page Ref: 5.2 OBJ: 5.2; G2 2) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 5.3 OBJ: 5.2, 5.3; G2 3) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 5.4 OBJ: 5.2, 5.3; G4 4) ANS: B PTS: 1 DIF: 3 REF: Page Ref: 5.4 OBJ: 5.2, 5.3; G2 5) ANS: D PTS: 1 DIF: 2 REF: Page Ref: 5.7 OBJ: 5.7; G2 6) ANS: E PTS: 1 DIF: 1 REF: Page Ref: 5.7 OBJ: 5.7; G4 7) ANS: E PTS: 1 DIF: 1 REF: Page Ref: 5.7 OBJ: 5.7; G2 8) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G4 9) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G4 10) ANS: D PTS: 1 DIF: 2 REF: Page Ref: 5.4 OBJ: 5.4; G4 11) ANS: C PTS: 1 DIF: 3 REF: Page Ref: 5.4 OBJ: 5.4; G4 12) ANS: B PTS: 1 DIF: 3 REF: Page Ref: 5.4 OBJ: 5.4; G4 13) ANS: C PTS: 1 DIF: 3 REF: Page Ref: 5.6 OBJ: 5.6; G4 14) ANS: D PTS: 1 DIF: 3 REF: Page Ref: 5.7 OBJ: 5.7; G4 15) ANS: A PTS: 1 DIF: 3 REF: Page Ref: 5.7 OBJ: 5.7; G4 16) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G4 17) ANS: A PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G4 18) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 5.2 OBJ: 5.2; G4 19) ANS: A PTS: 1 DIF: 3 REF: Page Ref: ) ANS: A PTS: 1 DIF: 3 REF: Page Ref: 5.5 1

8 21) ANS: D PTS: 1 DIF: 4 REF: Page Ref: 5.5 SHORT ANSWER 1) ANS: Work PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G4 2) ANS: grams PTS: 1 DIF: 3 REF: Page Ref: 5.5 3) ANS: 6.78 kj PTS: 1 DIF: 3 REF: Page Ref: 5.5 4) ANS: 868 PTS: 1 DIF: 3 REF: Page Ref: 5.5 5) ANS: 1929 kj PTS: 1 DIF: 3 REF: Page Ref: 5.5 6) ANS: 1 atm PTS: 1 DIF: 2 REF: Page Ref: 5.7 OBJ: 5.7; G2 7) ANS: sulfur PTS: 1 DIF: 2 REF: Page Ref: 5.8 OBJ: G7 TRUE/FALSE 1) ANS: T PTS: 1 DIF: 1 REF: Page Ref: 5.1 OBJ: 5.1; G2 2) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 5.1 OBJ: 5.1; G2 2

9 3) ANS: F PTS: 1 DIF: 1 REF: Page Ref: 5.1 OBJ: 5.1; G2 4) ANS: F PTS: 1 DIF: 1 REF: Page Ref: 5.8 OBJ: G2 5) ANS: T PTS: 1 DIF: 1 REF: Page Ref: 5.8 OBJ: G2 6) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 5.8 OBJ: G2 3

10 Unit 5 Practice Test [Answer Strip] ID : A _ E 6) _ C 11) _ D 14) _ A 17) _ A 1) _ E 7) _ B 18) _ B 12) _ C 2) _ A 19) _ C 3) _ C 8) _ A 15) _ C 13) _ A 20) _ B 4) _ C 9) _ D 21) _ D 10) _ C 16) _ D 5)

11 Unit 5 Practice Test [Answer Strip] ID : A _ T 1) _ T 2) _ F 3) _ F 4) _ T 5) _ T 6)