Potential Energy Diagrams

Question 1

What is an exothermic reaction?

Answer 1

. Heat energy is given out
. The products must have less energy than the reactants because heat energy has been released to the surroundings
. The enthalpy change always has a negative value

Question 2

What is an endothermic reaction?

Answer 2

. Heat energy is absorbed
. The products have more energy than the reactants because heat energy has been taken in from the surroundings
. The enthalpy change is always a positive value

Question 3

What is enthalpy?

Answer 3

. The enthalpy (H) is the heat stored by a substance

Question 4

What is the enthalpy change?

Answer 4

. The enthalpy change is the overall energy change that occurs when reactants are converted into products

Question 5

What is temperature the measure of?

Answer 5

. It’s a measure of the average kinetic energy of the particles in a substance
. If temperature is increased, then the particles would have more kinetic energy. Meaning they will collide with a greater force