Semester 2 Midterm Part 3 - Energy Diagrams

1. The chemical reaction between methane and oxygen is represented by the potential energy diagram and balanced equation below. Which potential energy interval in the diagram represents the activation energy of the forward reaction?

• A
• B
• C
• D

2. Does the diagram in question 1 represent a endothermic or exothermic reaction?

• endothermic
• exothermic

3. Would the net change in energy (enthalpy) be positive or negative for the chemical reaction in question number 1

• positive
• negative

4. Given the potential energy diagram below for a chemical reaction? Which line represents the net change in energy (enthalpy)?

• line 1
• line 2
• line 3
• line 4

5. Chemical cold packs are often used to reduce swelling after an athletic injury. The diagram represents the potential energy changes when a cold pack is activated. Which letter represents the net change in energy (enthalpy)

• A
• B
• C
• D

6. In an endothermic reaction heat is

• absorbed from the surroundings into the system
• released from the system into the surroundings

7. In the potential energy diagram below, which letter represents the activation energy of the forward reaction?

• A
• B
• C
• D

8. In the potential energy diagram below, which letter represents the activation energy of the reverse reaction?

• A
• B
• C
• D

10. Exothermic reactions feel

• hot
• cold

11. Endothermic reactions feel

• hot
• cold