Multiple choice chemistry questions

Directions: Please highlight or bold the correct answer.

1.      Radiant energy is:

a.   the energy stored within the structural units of chemical substances.

b.   the energy associated with the random motion of atoms and molecules.

c.   solar energy; i.e., energy that comes from the sun.

d.   energy available by virtue of an object’s position.

 

2.      Thermal energy is:

a.   the energy stored within the structural units of chemical substances.

b.   the energy associated with the random motion of atoms and molecules.

c.   solar energy; i.e., energy that comes from the sun.

d.   energy available by virtue of an object’s position.

 

3.      Chemical energy is:

a.   the energy stored within the structural units of chemical substances.

b.   the energy associated with the random motion of atoms and molecules.

c.   solar energy; i.e., energy that comes from the sun.

d.   energy available by virtue of an object’s position.

 

4.      Potential energy is:

a.   the energy stored within the structural units of chemical substances.

b.   the energy associated with the random motion of atoms and molecules.

c.   solar energy; i.e., energy that comes from the sun.

d.   energy available by virtue of an object’s position.

 

5.      Heat is a measure of:

a.   temperature.

b.   the change in temperature.

c.   thermal energy.

d.   thermal energy transferred between two bodies at different temperature.

 

6.      An endothermic reaction causes the surroundings to:

a.   warm up.

b.   become acidic.

c.   condense.

d.   decrease in temperature.

 

7.      An exothermic reaction causes the surroundings to:

a.   warm up.

b.   become acidic.

c.   condense.

d.   decrease in temperature.

 

8.      When 0.7521g of benzoic acid was burned in a calorimeter containing 1,000g of water, a temperature rise of 3.60°C was observed.  What is the heat capacity of the bomb calorimeter, excluding the water?  The heat of combustion of benzoic acid is –26.42 kJ/g.

a.   15.87 kJ/°C

b.   4.18 kJ/°C

c.   5.52 kJ/°C

d.   1.34 kJ/°C

 

9.      Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter.  The heat of combustion of naphthalene is –40.1 kJ/g.  When 0.8210g of naphthalene was burned in a calorimeter containing 1,000g of water, a temperature rise of 4.21°C was observed.  What is the heat capacity of the bomb calorimeter excluding the water?

a.   32.9 kJ/°C

b.   7.8 kJ/°C

c.   3.64 kJ/°C

d.   1.76 kJ/°C

 

10.    When 0.56g of Na(s) reacts with excess F2(g) to form NaF(s), 13.8 kJ of heat is evolved at standard-state conditions.  What is the standard enthalpy of formation ( D H°f) of NaF(s)?

a.   24.8 kJ/mol

b.   570 kJ/mol

c.   –24.8 kJ/mol

d.   –7.8 kJ/mol

 

11.    The combustion of butane produces heat according to the equation: 2C4H10(g) + 13O2(g) ® 8CO2(g) + 10H2O(l), D H°rxn = –5,314 kJ/mol.  What is the heat of combustion per gram of butane?

a.   –32.5 kJ/g

b.   –45.7 kJ/g

c.   –91.5 kJ/g

d.   –2,656 kJ/g

 

12.    Ethanol (C2H5OH) burns according to the equation: C2H5OH(l) + 3O2(g) ® 2CO2(g) + 3H2O(l), D H°rxn = –1367 kJ/mol.  How much heat is released when 35g of ethanol is burned?

a.   1,797 kJ

b.   1,367 kJ

c.   9.61 ´ 10–4 kJ

d.   1,040 kJ

 

13.    According to the first law of thermodynamics,:

a.   energy is neither lost nor gained in any energy transformations.

b.   perpetual motion is possible.

c.   energy is conserved in quality, but not in quantity.

d.   energy is being created as time passes.  We have more energy in the universe now than when time began.

 

14.    A gas is compressed in a cylinder from a volume of 20.0 L to 2.0 L by a constant pressure of 10.0 atm.  Calculate the amount of work done on the system.

a.   1.01 ´ 104 J

b.   –180 J

c.   1.81 ´ 104 J

d.   –1.81 ´ 104 J

 

15.    Which of the following processes always results in an increase in the 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.

 

16.    A calorimeter measures:

a.   the change in temperature of a process/reaction.

b.   the change in volume of a process/reaction.

c.   the change in pressure of a process/reaction.

d.   the change in randomness of a process/reaction.

e.   none of the choices apply.

 

17.    Most chemical processes are:

a.   spontaneous.

b.   random.

c.   endothermic.

d.   exothermic.

e.   man-made.

 

18.    In the natural world, most chemical processes occur in contact with the Earth’s atmosphere at:

a.   a constant pressure.

b.   a constant temperature.

c.   a constant volume.

d.   a constant amount.

e.   none of the choices apply.

 

19.    Which of the following processes do not involve energy changes?

a.   Plants converting carbon dioxide to oxygen, water, and sugars

b.   Animals digesting food

c.   Automobile burning fuel

d.   Animals breathing in oxygen

e.   None of the choices apply

 

20.    The idea gas law relates:

a.   volume and pressure in a predictable way.

b.   temperature and volume in a predictable way.

c.   pressure and temperature in a predictable way.

d.   quantities and pressure in a predictable way.

e.   all of the choices apply.