Chemistry Chapter 5 Quiz

ΔH for the reaction IF5 (g) → IF3 (g) + F2 (g) is ________ kJ, give the data below. IF (g) + F2 (g) → IF3 (g) ΔH = -390 kJ IF (g) + 2F2 (g) → IF5 (g) ΔH = -745 kJ A) +355 B) -1135 C) +1135 D) +35 E) -35

A) +355

) Consider the following two reactions: A → 2B ΔH°rxn = 456.7 kJ/mol A → C ΔH°rxn = -22.1 kJ/mol Determine the enthalpy change for the process: 2B → C A) -478.8 kJ/mol B) -434.6 kJ/mol C) 434.6 kJ/mol D) 478.8 kJ/mol E) More information is needed to solve the problem.

A) -478.8 kJ/mol

Given the following reactions Fe2O3 (s) + 3CO (s) → 2Fe (s) + 3CO2 (g) ΔH = -28.0 kJ 3Fe (s) + 4CO2(s) → 4CO (g) + Fe3O4(s) ΔH = +12.5 kJ the enthalpy of the reaction of Fe2O3 with CO 3Fe2O3 (s) + CO (g) → CO2 (g) + 2Fe3O4 (s) is ________ kJ. A) -59.0 B) 40.5 C) -15.5 D) -109 E) +109

A) -59.0

Given the following reactions N2 (g) + 2O2 (g) → 2NO2 (g) ΔH = 66.4 kJ 2NO (g) + O2 (g) → 2NO2 (g) ΔH = -114.2 kJ the enthalpy of the reaction of the nitrogen to produce nitric oxide N2 (g) + O2 (g) → 2NO (g) is ________ kJ. A) 180.6 B) -47.8 C) 47.8 D) 90.3 E) -180.6

A) 180.6

The value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l) → CO (g) + 2H2 (g) How much heat is consumed when 87.1 g of hydrogen gas is formed? A) 2.76 × 103 kJ B) 5.52 × 103 kJ C) -5.52 × 103 kJ D) -2.76 × 103 kJ E) -128.1 kJ

A) 2.76 × 103 kJ

What is the molar heat capacity (in J/mol-K) of liquid bromine? The specific heat of liquid bromine is 0.226 J/g-K. A) 36.1 J/mol-K B) 707 J/mol-K C) 18.1 J/mol-K D) 9.05 J/mol-K E) 0.226 J/mol-K

A) 36.1 J/mol-K

) What is the kinetic energy of a 55.2 g object moving at 135 m/s. A) 503 J B) 5.03 × 105 J C) 1.01 × 103 J D) 3.73 J E) 3.73 × 103 J

A) 503 J

) Of the following, which one is a state function? A) H B) q C) w D) heat E) none of the above

A) H

Which of the following is a statement of Hess's law? A) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps. B) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the product of the enthalpy changes for the individual steps. C) The ΔH for a process in the forward direction is equal in magnitude and opposite in sign to the ΔH for the process in the reverse direction. D) The ΔH for a process in the forward direction is equal to the ΔH for the process in the reverse direction. E) The ΔH of a reaction depends on the physical states of the reactants and products.

A) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps.

For the combustion reaction of methane, ΔH°f is zero for ________. CH4 (g) + O2 (g) → 2H2O(g) + CO2 (g) A) O2 (g) B) CH4 (g) C) CO2 (g) D) H2O (g) E) Both O2 (g) and CH4 (g)

A) O2 (g)

2) 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 decompression

A) adding heat to the system

) A chemical reaction that absorbs heat from the surroundings is said to be ________ and has a ________ ΔH at constant pressure. A) endothermic, positive B) endothermic, negative C) exothermic, negative D) exothermic, positive E) exothermic, neutral

A) endothermic, positive

21) All of the following are considered fossil fuels except ________. A) hydrogen B) anthracite coal C) crude oil D) natural gas E) petroleum

A) hydrogen

28) The enthalpy change for the following reaction is -483.6 kJ: 2H2 (g) + O2 (g) → 2H2O (g) Therefore, the enthalpy change for the following reaction is ________ kJ. 4H2 (g) + 2O2 (g) → 4H2O (g) A) -483.6 B) -967.2 C) 2.34 × 105 D) 483.6 E) 967.2

B) -967.2

The specific heat of liquid bromine is 0.226 J/g-K. How much heat (J) is required to raise the temperature of 10.0 mL of bromine from 25.00 °C to 27.30 °C? The density of liquid bromine: 3.12 g/mL. A) 5.20 J B) 16.2 J C) 300 J D) 32.4 J E) 10.4 J

B) 16.2 J

26) The value of ΔH° for the reaction below is -126 kJ. ________ kj are released when 2.00 mol of NaOH is formed in the reaction? 2Na2O2 (s) + 2H2O (l) → 4NaOH (s) + O2 (g) A) 252 B) 63 C) 3.9 D) 7.8 E) -126

B) 63

Hydrogen gas and bromine gas react to form hydrogen bromide gas. How much heat (kJ) is released when 155 grams of HBr is formed in this reaction? ΔH° = -72 kJ. A) 137 B) 69 C) -69 D) -137 E) 1.12 × 105

B) 69

When a system ________, ΔE is always negative. A) absorbs heat and does work B) gives off heat and does work C) absorbs heat and has work done on it D) gives off heat and has work done on it E) None of the above is always negative.

B) gives off heat and does work

9) A ________ ΔH corresponds to an ________ process. A) negative, endothermic B) negative, exothermic C) positive, exothermic D) zero, exothermic E) zero, endothermic

B) negative, exothermic

Given the data in the table below, ΔH°rxn for the reaction 3NO2 (g) + H2O (l) → 2HNO3 (aq) + NO (g) is ________ kJ. A) 64 B) 140 C) -140 D) -508 E) -64

C) -140

39) Given the data in the table below, ΔH°rxn for the reaction Ca(OH)2 + 2H3AsO4 → Ca(H2AsO4)2 + 2H2O is ________ kJ. A) -744.9 B) -4519 C) -4219 D) -130.4 E) -76.4

C) -4219

20) The term standard conditions with respect to enthalpy change means ________. A) 1 atm and 0 K B) 1 atm and 1 L C) 1 atm and 298 K D) 1 L and 0 K E) 1 atm and 1 °C

C) 1 atm and 298 K

22) Calculate the kinetic energy in joules of an automobile weighing 4345 lb and traveling at 75 mph. A) 5.5 × 105 J B) 5.5 × 10-5 J C) 1.1 × 106 J D) 2.2 × 106 J E) 2.2 × 10-6 J

C) 1.1 × 106 J

27) The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of (l)? 2C6H6 (l) + 15O2 (g) → 12CO2 (g) + 6H2O (l) A) 1.34 × 103 B) 5.23 × 104 C) 669 D) 2.68 × 103 E) -6535

C) 669

) The units of specific heat are ________. A) K/J or °C/J B) J/K or J/°C C) J/g-K or J/g-°C D) J/mol E) g-K/J or g-°C/J

C) J/g-K or J/g-°C

18) For the following reactions, the ΔH°rxn is NOT equal to ΔH°f for the product except for ________. A) CH4 (g) + 2Cl2 (g) → CH2Cl2 (l) + 2HCl (g) B) N2 (g) + O3 (g) → N2O3 (g) C) Xe (g) + 2F2 (g) → XeF4 (g) D) 2CO (g) + O2 (g) → 2CO2 (g) E) C (diamond) + O2 (g) → CO2 (g)

C) Xe (g) + 2F2 (g) → XeF4 (g)

) The reaction 4Al (s) + 3O2 (g) → 2 Al2O3 (s) ΔH° = -3351 kJ is ________, and therefore heat is ________ by the reaction. A) endothermic, released B) endothermic, absorbed C) exothermic, released D) exothermic, absorbed E) thermoneutral, neither released nor absorbed

C) exothermic, released

24) The ΔE of a system that releases 12.4 J of heat and does 4.2 J of work on the surroundings is ________ J. A) 16.6 B) 12.4 C) 4.2 D) -16.6 E) -8.2

D) -16.6

The temperature of a 15-g sample of lead metal increases from 22 °C to 37 °C upon the addition of 29.0 J of heat. The specific heat capacity of the lead is ________ J/g-K. A) 7.8 B) 1.9 C) 29 D) 0.13 E) -29

D) 0.13

30) The molar heat capacity of an unknown substance is 92.1 J/mol-K. If the unknown has a molar mass of 118 g/mol, what is the specific heat (J/g-K) of this substance? A) 1.28 B) -92.1 C) 1.09 × 104 D) 0.781 E) 92.1

D) 0.781

) The specific heat capacity of lead is 0.13 J/g-K. How much heat (in J) is required to raise the temperature of of lead from 22 °C to 37 °C? A) 2.0 J B) -0.13 J C) 5.8 × 10-4 J D) 29 J E) 0.13 J

D) 29 J

Given the following reactions H2O (l) → H2O (g) ΔH = 44.01 kJ 2H2 (g) + O2 (g) → 2H2O (g) ΔH = -483.64 kJ the enthalpy for the decomposition of liquid water into gaseous hydrogen and oxygen 2H2O (l) → 2H2 (g) + O2 (g) is ________ kJ. A) -395.62 B) -527.65 C) 439.63 D) 571.66 E) 527.65

D) 571.66

) Which of the following is a statement of the first law of thermodynamics? A) Ek = mv2 B) A negative ΔH corresponds to an exothermic process. C) ΔE = Efinal - Einitial D) Energy lost by the system must be gained by the surroundings. E) 1 cal = 4.184 J (exactly)

D) Energy lost by the system must be gained by the surroundings.

4) Which one of the following conditions would always result in an increase in the internal energy of a system? A) The system loses heat and does work on the surroundings. B) The system gains heat and does work on the surroundings. C) The system loses heat and has work done on it by the surroundings. D) The system gains heat and has work done on it by the surroundings. E) None of the above is correct

D) The system gains heat and has work done on it by the surroundings.

3) The internal energy of a system ________. A) is the sum of the kinetic energy of all of its components B) is the sum of the rotational, vibrational, and translational energies of all of its components C) refers only to the energies of the nuclei of the atoms of the component molecules D) is the sum of the potential and kinetic energies of the components E) none of the above

D) is the sum of the potential and kinetic energies of the components

6) Which one of the following is an endothermic process? A) ice melting B) water freezing C) boiling soup D) Hydrochloric acid and barium hydroxide are mixed at 25 °C: the temperature increases. E) Both A and C

E) Both A and C

10) All of the following statements are true except ________. A) Internal energy is a state function. B) The enthalpy change for a reaction is equal in magnitude, but opposite in sign, to the enthalpy change for the reverse reaction. C) The enthalpy change for a reaction depends on the state of the reactants and products. D) The enthalpy of a reaction is equal to the heat of the reaction. E) Enthalpy is an intensive property.

E) Enthalpy is an intensive property.

19) For the following reactions, the ΔH°rxn is NOT equal to ΔH°f for the product except for ________. A) H2 (g) + 1/2 O2 (g) → H2O (l) B) H2 (g) + O2 (g) → H2O2 (l) C) 2C (s, graphite) + 2H2 (g) → C2H4 (g) D) 1/2 N2 (g) + O2 (g) → NO2 (g) E) all of the above

E) all of the above

1) Objects can possess energy as ________. (a) endothermic energy (b) potential energy (c) kinetic energy A) a only B) b only C) c only D) a and c E) b and c

E) b and c

When ________ is constant, the enthalpy change of a process equal to the amount of heat transferred into or out of the system? A) temperature B) volume C) pressure and volume D) temperature and volume E) pressure

E) pressure