Thermochemistry

Written by Dr. Ayesha Nadeem (Chemistry)

Class 11 · Chemistry · 8 questions

Name: ____________________ Date: ____________

In an exothermic reaction, the enthalpy change is:
- A Positive
- B Negative
- C Zero
- D Infinite
Hess's law states that the enthalpy change of a reaction depends on:
- A The speed
- B The path taken
- C Only the initial and final states
- D The catalyst
The standard enthalpy of formation of an element in its standard state is:
- A 0
- B -1 kJ/mol
- C 1 kJ/mol
- D 100 kJ/mol
Bond breaking is:
- A Exothermic
- B Endothermic
- C Neither
- D Always a catalyst process
Heat of combustion is the heat released when one mole of a substance:
- A Melts
- B Boils
- C Dissolves
- D Burns completely in oxygen
The enthalpy change for the reaction C + O2 giving CO2 is -394 kJ/mol. This reaction is:
- A Not possible
- B Exothermic
- C Endothermic
- D Thermoneutral
The heat needed to raise 1 g of water by 1 degree C is about:
- A 0.42 J
- B 420 J
- C 42 J
- D 4.2 J
The standard state of a substance refers to its state at:
- A Any pressure
- B 100 degrees C only
- C 1 atm pressure and 298 K
- D 0 atm and 0 K

Answer key

1. B, 2. C, 3. A, 4. B, 5. D, 6. B, 7. D, 8. C