Chem Unit 5 MC Questions

d

Calculate the kinetic energy in joules of a 150 lb jogger (68.1 kg) traveling at 12.0 mile/hr (5.36 m/s). a. 1.96 ´ 103 J b. 365 J c. 183 J d. 978 J e. 68.1 J

d

Calculate the value of ÄE in joules for a system that loses 115 J of heat and has 150 J of work performed on it by the surroundings. a. -35 J b. -115 J c. +265 J d. +35 J e. -265 J

a

For a given process at constant pressure, w is positive. This means that the process involves ____. a. work being done by the system on the surroundings b. no work being done c. work being done by the surroundings on the system d. work being done against a vacuum e. an equal amount of work done on the system and by the system

b

Given the data in the table below, ΔH°rxn for the reaction 3NO2 (g) + H2O (l) → 2HNO3 (aq) + NO (g) is ____ kJ. mc091-1.jpg a. 140 b. -140 c. 64 d. -64 e. -508

b

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) + 2 Fe3O4 (s) is ____ kJ. a. -15.5 b. -59.0 c. -109 d. 40.5 e. +109

a

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) + 2 Fe3O4 (s) is ____ kJ. a. -59.0 b. -15.5 c. -109 d. +109 e. 40.5

b

Given the following reactions N2 (g) + O2 (g) → 2NO (g) ΔH = +180.7 kJ 2N2O (g) → O2 (g) + 2N2 (g) ΔH = -163.2 kJ the enthalpy of reaction for 2N2O (g) → 2NO (g) + N2 (g) is ____ kJ. a. -145.7 b. 17.5 c. -343.9 d. 343.9 e. 145.7

e

Given the following reactions N2 (g) + O2 (g) → 2NO (g) ΔH = +180.7 kJ 2NO (g) + O2 (g) → 2NO2 (g) ΔH = -113.1 kJ the enthalpy of reaction for 4NO (g) → 2NO2 (g) + N2 (g) is ____ kJ. a. 67.6 b. -45.5 c. 45.5 d. 293.8 e. -293.8

e

Given the following reactions N2 (g) + O2 (g) → 2NO (g) ΔH = +180.7 kJ 2NO( g) + O2 (g) → 2NO2 (g) ΔH = -113.1 kJ the enthalpy for the decomposition of nitrogen dioxide into molecular nitrogen and oxygen 2NO2 (g) → N2 (g) + 2O2 (g) is ____ kJ. a. 67.6 b. 45.5 c. 293.8 d. -293.8 e. -67.6

c

Of the following, ΔH°f is not zero for ____. a. Br2 (l) b. P4 (s, white) c. Sc (g) d. Ca (s) e. Si (s)

a

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. -967.2 b. 967.2 c. 483.6 d. 2.34 ´ 105 e. -483.6

d

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

The molar heat capacity of a compound with the formula C2H6 SO is 88.0 J/mol-K. The specific heat of this substance is ____ J/g-K. a. -88.0 b. 4.89 c. 88.0 d. 1.13 e. 6.88 ´ 103

false

The primary component of natural gas is propane. True False

b

The value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l) → CO (g) + 2H2 (g) How many kJ of heat are consumed when 5.75 g of CO (g) is formed as shown in the equation? a. 162 kJ b. 26.3 kJ c. 62.0 kJ d. 8.3 kJ e. 23.3 kJ

d

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s) How many kJ of heat are released when 5.75 g of Ba (s) reacts completely with oxygen to form BaO (s)? a. 26.3 kJ b. 193 kJ c. 96.3 kJ d. 23.2 kJ e. 46.4 kJ

a

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s) How many kJ of heat are released when 15.75 g of Ba (s) reacts completely with oxygen to form BaO (s)? a. 63.5 kJ b. 20.8 kJ c. 70.3 kJ d. 114 kJ e. 35.1 kJ

false

Units of energy include newtons, joules, and calories. True False

b

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.

a

he value of ΔH° for the reaction below is -336 kJ. Calculate the heat (kJ) released to the surroundings when 23.0 g of HCl is formed. CH4 (g) + 3Cl2 (g) → CHCl3 (l) + 3HCl (g) a. 70.7 kJ b. 2.57 ´ 103 kJ c. 177 kJ d. 211 kJ e. -336 kJ