Thermochemistry Review

Front

What is the First Law of Thermodynamics?

Back

Energy can neither be created nor destroyed; only transformed from one form to another.

Front

What is an endothermic reaction?

Back

A reaction that absorbs energy from its surroundings.

Front

What is an exothermic reaction?

Back

A reaction that releases energy to its surroundings.

Front

What does a negative enthalpy change (ΔH) indicate about a reaction?

Back

The reaction is exothermic.

Front

What is the enthalpy of fusion (ΔH_fus)?

Back

The amount of energy required to change a substance from solid to liquid at its melting point.

Front

What is the enthalpy of vaporization (ΔH_vap)?

Back

The amount of energy required to change a substance from liquid to gas at its boiling point.

Front

How do you calculate the energy required to freeze a substance?

Back

Use the formula: Energy = mass (g) / molar mass (g/mol) * ΔH_fus (kJ/mol).

Front

What is the significance of the Law of Conservation of Matter in thermochemistry?

Back

Matter cannot be created or destroyed in a chemical reaction; it only changes forms.

Front

What is thermal equilibrium?

Back

A state in which two objects in contact do not exchange energy because they are at the same temperature.

Front

What is specific heat capacity?

Back

The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.