Grade 12 Thermochemistry Worksheet
A comprehensive worksheet for Grade 12 Chemistry students covering key concepts in thermochemistry including enthalpy, entropy, Gibbs free energy, and Hess's Law.
Includes
Standards
Grade 12 Thermochemistry Worksheet
Name:
Date:
Score:
Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. Which of the following statements is true for an exothermic reaction?
ΔH > 0
ΔH < 0
ΔS > 0
ΔS < 0
2. Hess's Law states that:
The total energy of an isolated system is constant.
Entropy of the universe tends to a maximum.
The enthalpy change of a reaction is independent of the pathway between initial and final states.
The rate of a chemical reaction is proportional to the product of the concentrations of the reactants.
3. The measure of the disorder or randomness of a system is called .
4. A reaction that absorbs heat from its surroundings is an reaction.
5. The total heat content of a system at constant pressure is known as .
6. A spontaneous reaction always proceeds quickly.
True
False
7. The standard enthalpy of formation for an element in its most stable state is zero.
True
False
8. Define Gibbs Free Energy and explain its significance in determining the spontaneity of a chemical reaction.
9. Calculate the enthalpy change (ΔH) for the reaction: C(s) + O₂(g) → CO₂(g) given the following data:
C(s) + ½ O₂(g) → CO(g) ΔH = -110.5 kJ/mol
CO(g) + ½ O₂(g) → CO₂(g) ΔH = -283.0 kJ/mol