Thermochemistry Problems

Which of the following has a standard enthalpy of formation of 0 kJ/mol?

• H₂O (l)

• H₂O(g)

• O (g)

• O₂ (g)

If the enthalpy change of the reaction is a positive number, this means:

• The heat can be treated as a reactant

• The temperature will rise

• The reaction is giving off heat

• The reaction is exothermic

If the enthalpy change of the reaction is a positive number, which of the following is true?

• The reaction is exothermic

• The products are more stable than the reactants

• The products will be higher on a diagram than the reactants

• The reaction gives off heat.

Which of the following represents ΔH?

• B

• C

• D

• A-D

Which of the following is true about this reaction?

• It is exothermic

• The products are less stable than the reactants

• The reaction absorbed energy

• The reaction will not occur

If this reaction used a catalyst, which of the following would be true?

• ΔH would be greater

• ΔH would be smaller

• B would be greater

• B would be smaller

The amount of heat energy required in order to raise the temperature of 1 gram of a substance by 1 degree C is called:

• calorimetry

• enthalpy

• specific heat capacity

• heat of formation

The bond energy is:

• The amount of energy released when a bond forms

• The amount of energy stored within the bond

• The amount of energy required to break a bond

• The amount of energy required to form a bond

100 mL of HCl is combined with 100 mL of NaOH. To determine the heat of solution, we would:

• Use a mass of 100 g

• Use a mass of 200 g

• Use the average specific heat of each substance

• Measure the energy in the bonds themselves

In a calorimetry problem where we are calculating the heat of solvation, we should:

• Use the specific heat of the compound being dissolved

• Use the temperature of the classroom as our initial temperature

• Change the sign of q at the end of the problem

• Use the mass of the ionic compound being dissolved