Module 4: Reaction Rates and Chemical Equilibrium

Label the parts of the reaction diagram.

a

b

c

products

activation energy

reactants

Which of the following would increase the rate of reaction? Select ALL correct answers.

• Addition of a catalytst

• Increasing the temperature

• Decreasing activation energy

• Decreasing the energy of the products

• Increasing the concentration of reactants

Tags

NGSS.HS-PS1-5

Reaction rates are increased by ​ (a)   the ​ (b)   between reactants.

• increasing
• frequency of collisions
• decreasing
• energy difference

Tags

NGSS.HS-PS1-5

What is activation energy?

• Minimum amount of energy required to start a chemical reaction
• The energy required to stop a chemical reaction
• The maximum amount of energy required to start a chemical reaction
• The energy released during a chemical reaction

Tags

NGSS.HS-PS1-5

What is the activation energy (in kJ) of the reaction shown in the diagram?

Mathematical Equivalence

ON

Tags

NGSS.HS-PS1-4

Substance that increases the rate of reaction by decreasing activation energy.

How do catalysts speed up the rate of reaction?

• By decreasing the energy difference between producst and reactants

• By adding energy to a reaction

• By decreasing the activation energy required for a reaction

• By increasing the kinetic energy of reactants

Tags

NGSS.HS-PS1-5

In exothermic reactions, energy is ​ (a)   .

In endothermic reactions, energy is ​ (b)   .

• released
• absorbed

Answer explanation

Remember the "exo" sounds like "exit"

In exothermic reactions, energy exits (energy is released)

Remember the "endo" sounds like "into"

In endothermic reactions, energy go into (energy is absorbed)

Tags

NGSS.HS-PS1-4

Organize these options into the right categories

Groups:

(a) Exothermic reactions

,

(b) Endothermic reactions

• ΔE is positive

• Products are lower energy than reactants

• A + B --> C + energy

• Energy is released

• Products are higher energy than reactants

• ΔE is negative

• Energy is absorbed

• Energy is a reactant

• X + Y + energy --> Z

• Energy is a product

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Is this reaction exothermic or endothermic?

• Exothermic, because the products are lower energy than the reactants

• Endothermic, because the products are lower energy than the reactants

• Exothermic, because the products are higher energy than the reactants

• Endothermic, because the products are higher energy than the reactants

Answer explanation

In exothermic reactions energy is released. This means that the products will be lower energy than the reactants.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

NGSS.HS-PS3-4