Energetics

Question 1

Why do you mix the solutions in Calorimetry?

Answer 1

To mix the solutions together to ensure they react and to ensure temperature is the same in both solutions

Question 2

Formula for enthalpy change

Answer 2

Total energy absorbed to break bonds
MINUS
total energy released in making bonds

Question 3

Describe when a reaction is exothermic

Answer 3

The energy released by forming bonds is greater than the energy used to break the original bonds.
(Opposite of endothermic)

Question 4

Describe when a reaction is endothermic

Answer 4

The energy used to break bonds is greater than the energy released by forming them
(Opposite of exothermic)

Question 5

Why do you have to measure the spirit burner and fuel’s mass immediately?

Answer 5

To ensure mass is recorded before any fuel evaporates

Question 6

Identify black solid formed when investigating enthalpy change burning liquid fuel

Answer 6

Carbon

Question 7

How to prevent heat energy transfer in a enthalpy change experiment

Answer 7

-Use a polystyrene cup to prevent heat transfer as its a poor conductor of heat energy

-Mix the solutions to ensure the temperature is the same throughout both solutions

-Use a bung or lid to prevent heat energy being lost to surroundings via transfer