MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 Chapter 5 Practice Test Jessica Miller AP Chemistry Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) H for the reaction 1) IF5 (g) IF3 (g) + F2 (g) is kj, give the data below. IF (g) + F2 (g) IF3 (g) IF (g) + 2 F2 (g) IF5 (g) H = -390 kj H = -745 kj A) +355 B) +35 C) -35 D) E) ) The value of H for the reaction below is kj: 2) 2Ba (s) + O2 (g) 2BaO (s) How many kj of heat are released when g of Ba (s) reacts completely with oxygen to form BaO (s)? A) 63.5 B) 70.3 C) 20.8 D) 35.1 E) 114 3) Given the data in the table below, H rxn for the reaction 3) Ag2O (s) + H2S (g) Ag2S (s) + H2O (l) Substance Hf (kj/mol) Ag2O (s) Ag2S (s) H2S (g) H2O (l) -286 A) -308 B) -267 C) -202 D) -370 E) More data are needed to complete the calculation. 1

2 4) Given the data in the table below, H rxn for the reaction 4) C2H5OH (l) + O2 (g) CH3CO2H (l) + H2O (l) Substance Hf (kj/mol) C2H4 (g) 52.3 C2H5OH (l) CH3CO2H (l) H2O (l) A) B) C) D) E) The value of Hf of O2 (g) is required for the calculation. 5) Which one of the following is an exothermic process? 5) A) boiling soup B) ice melting C) condensation of water vapor D) water evaporating E) Ammonium thiocyanate and barium hydroxide are mixed at 25 C: the temperature drops. 6) Calculate the kinetic energy in joules of a 150 lb jogger (68.1 kg) traveling at 12.0 mile/hr (5.36 m/s). 6) A) 365 B) 183 C) 68.1 D) 978 E) ) The value of H for the reaction below is kj: 7) CH3OH (l) CO (g) + 2H2 (g) How many kj of heat are consumed when 15.5 g of CH3OH (l) decomposes as shown in the equation? A) 62.0 B) 0.48 C) 32 D) 8.3 E)

3 8) Given the data in the table below, H rxn for the reaction 8) 4NH3 (g) + 5O2 (g) 4NO (g) + 6H2O (l) Substance Hf (kj/mol) H2O (l) -286 NO (g) 90 NO2 (g) 34 HNO3 (aq) -207 NH3 (g) -46 A) B) -150 C) D) E) The Hf of O2 (g) is needed for the calculation. 9) Of the following, which one is a state function? 9) A) q B) H C) w D) heat E) none of the above 10) The reaction 10) 4Al (s) + 3O2 (g) 2Al2O3 (s) H = kj is, and therefore heat is by the reaction. A) exothermic, released B) endothermic, absorbed C) endothermic, released D) exothermic, absorbed E) thermoneutral, neither released nor absorbed 11) The E of a system that releases 12.4 J of heat and does 4.2 J of work on the surroundings is J. A) 4.2 B) 16.6 C) -8.2 D) E) ) For a given process at constant pressure, H is negative. This means that the process is. A) energy B) endothermic C) equithermic D) exothermic E) a state function 11) 12) 3

4 13) The most abundant fossil fuel is. 13) A) natural gas B) uranium C) petroleum D) hydrogen E) coal 14) Calculate H (in kj) for reaction 3. 14) 2S (s) + 3O2 (g) 2SO3 (g) S (s) + O2 (g) SO2 (g) H = -790 kj H = -297 kj the enthalpy of the reaction in which sulfur dioxide is oxidized to sulfur trioxide 2SO2 (g) + O2 (g) 2SO3 (g) A) 196 B) C) 1087 D) -196 E) ) Of the following, Hf is not zero for. 15) A) N2 (g) B) O2 (g) C) F2 (s) D) Cl2 (g) E) C (graphite) 16) When a system, E is always negative. 16) A) gives off heat and has work done on it B) absorbs heat and does work C) absorbs heat and has work done on it D) gives off heat and does work E) none of the above is always negative. 17) The change in the internal energy of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings is J. A) 10,155 B) 5,155 C) D) -10,155 E) -5,155 17) 18) The units of of heat capacity are. 18) A) g-k/j or g- C/J B) J/mol C) J/K or J/ C D) J/g-K or J/g- C E) K/J or C/J 4

5 19) H for an endothermic process is while H for an exothermic process is. 19) A) positive, negative B) positive, zero C) negative, positive D) zero, positive E) zero, negative 20) Objects can possess energy as. 20) (a) endothermic energy (b) potential energy (c) kinetic energy A) a only B) b only C) c only D) b and c E) a and c 21) When a system, E is always negative. 21) A) absorbs heat and has work done on it B) absorbs heat and does work C) gives off heat and has work done on it D) gives off heat and does work E) none of the above is always negative. 22) The value of H for the reaction below is -790 kj. The enthalpy change accompanying the reaction of 0.95 g of S 22) 2S (s) + 3O2 (g) 2SO3 (g) A) 12 B) 23 C) -23 D) -12 E) ) Given the data in the table below, H rxn for the reaction 23) 2SO2 (g) + O2 (g) 2SO3 (g) Substance Hf (kj/mol) SO2 (g) -297 SO3 (g) -396 SO2Cl2 (g) -364 H2SO4 (l) -814 H2O (l) -286 A) -99 B) 99 C) -198 D) 198 E) The H f of O2 (g) is needed for the calculation. 5

6 24) Which one of the following conditions would always result in an increase in the internal energy of a system? A) The system gains heat and has work done on it by the surroundings. B) The system loses heat and does work on the surroundings. C) The system gains heat and does work on the surroundings. D) The system loses heat and has work done on it by the surroundings. E) None of the above is correct. 24) 25) Calculate the kinetic energy in J of an electron moving at m/s. The mass of an electron is g. A) B) C) D) E) ) The value of E for a system that performs 213 kj of work on its surroundings and loses 79 kj of heat A) -292 B) +292 C) +134 D) -134 E) ) 26) 27) Which of the following is a statement of Hess's law? 27) A) If a reaction is carried out in a series of steps, the H for the reaction will equal the sum of the enthalpy changes for the individual steps. B) The H for a process in the forward direction is equal in magnitude and opposite in sign to the H for the process in the reverse direction. C) The H for a process in the forward direction is equal to the H for the process in the reverse direction. D) If a reaction is carried out in a series of steps, the H for the reaction will equal the product of the enthalpy changes for the individual steps. E) The H of a reaction depends on the physical states of the reactants and products. 28) A H corresponds to an process. 28) A) negative, endothermic B) negative, exothermic C) positive, exothermic D) zero, exothermic E) zero, endothermic 6

7 29) Given the following reactions 29) CaCO3 (s) CaO (s) + CO2 (g) C (s, graphite) + O2 (g) CO2 (g) H = kj H = kj the enthalpy of the reaction CaCO3 (s) CaO (s) + C (s, graphite) + O2 (g) A) B) C) D) E) ) Which one of the choices below is not considered a fossil fuel? 30) A) crude oil B) natural gas C) hydrogen D) petroleum E) anthracite coal 7