Energy and Chemical change

What type of reaction is this?

• Endothermic
• Exothermic

What letter represents the activation energy?

• A
• B
• C
• D

Activation energy is required to start a chemical reaction. What is activation energy?

• The energy needed for a reaction to occur
• The minimum amount of energy needed for a reaction to potentially occur
• The energy added by a catalyst
• The energy possessed by the products

What is represented by interval C?

• Potential energy of the reactants

• Potential energy of the products

• Activation Energy

• Heat of reaction

Which interval represents the activation energy?

• A

• B

• C

• D

How much energy does it take to start this reaction?

• 20 kJ

• 100 kJ

• 60 kJ

• -60 kJ

Is this reaction endothermic or exothermic?

• Endothermic

• Exothermic

What is the heat of reaction for the reaction shown in this PE diagram?

• 50kJ

• -50 kJ

• 200 kJ

• -200 kJ

An endothermic reaction is

• A reaction that absorbs heat, and the products have less PE than the reactants

• A reaction that releases heat, and the products have more PE than the reactants

• A reaction that absorbs heat, and the products have more PE than the reactants

• A reaction that releases heat, and the products have more PE than the reactants

Exothermic reactions release heat energy to the surroundings.

• true
• false