C6

Question 1

Define an exothermic reaction

Answer 1

A reaction that releases thermal energy to the surroundings, it increases the temperature of the surroundings

Question 2

Define an endothermic reaction

Answer 2

A reaction that takes in thermal energy from the surroundings, which decreases the temperature of the surroundings

Question 3

Bond breaking is?

Answer 3

Bond breaking is an endothermic process

Question 4

Bond forming is?

Answer 4

Bond forming is an exothermic
process

Question 5

energy level diagrams =

Answer 5

pathway diagrams

Question 6

define enthalpy

Answer 6

Enthalpy is a measure of the potential energy a chemical has and is given the symbol H

Question 7

What is a pathway diagram and why is it used?

Answer 7

A pathway diagram is used to show the energy pathway for a chemical reaction as reactants change into products. It shows how the thermal energy in the chemicals changes as the reaction proceeds.

Question 8

Symbol for enthalpy change?

Answer 8

ΔH

Question 9

What does the pathway diagram for exothermic reactions look like?

Answer 9

The products have less energy than the reactants, and the excess is given out to the surroundings. So, the enthalpy change is a negative (-ΔH)

Question 10

What does the pathway diagram for endothermic reactions look like?

Answer 10

The products have more energy than the reactants, and they take this energy from their surroundings. So, the enthalpy change is a positive (+ΔH)

Question 11

define activation energy

Answer 11

Activation energy is the minimum amount of energy required for a reaction to occur

Question 12

know how to draw pathway diagrams

Answer 12

check the slides + the textbook