AP Chemistry Energy Profile

What type of reaction is shown in the reaction pathway?

• endothermic reaction
• exothermic reaction

Tags

NGSS.HS-PS1-4

B represents

• energy absorbed
• energy released
• activation energy (forward reaction)

• activation energy (backwards reaction)

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What is the activation energy?

• The minimum kinetic energy of the products

• The energy of the reactants

• The minimum kinetic energy needed by colliding reactants to form the products

• The energy lost in the reaction as particles collide to form the products

True or False:

The magnitude of E_a is related to the strength and number of existing bonds in reactants

• True

• False

Tags

NGSS.HS-PS1-4

Shown are the energy profiles of two reactions.
The reaction with the lowest activation energy is

• A + B → C + D
• X → Y + Z
• C + D → A + B
• Z + Y → X

Tags

NGSS.HS-PS1-4

Which of the following are true when a catalyst is used in a chemical reaction?

• • Enthalpy of reaction is lower.
  • Activation energy for the reaction is lower.
• • Enthalpy of reaction is same.
  • Activation energy for the reaction is lower.
• • Enthalpy of reaction is the lower.
  • Activation energy for the reaction is same.
• • Enthalpy of the reaction is same.
  • Activation energy for the reaction is same.

Which of the following best explains how a catalyst increases the rate of reaction?

• a catalyst provides an alternative pathway of lower activation energy, thus increases the proportion of effective collisions

• a catalyst provides an alternative pathway of higher activation energy, thus increases the proportion of effective collisions

• a catalyst provides an alternative pathway of lower activation energy for the forward reaction only

• a catalyst provides an alternative pathway of lower activation energy for the back reaction only

Tags

NGSS.HS-PS1-5

What letter represents the activation energy?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-4

What is the activation energy?

• 100 kJ

• 250 kJ

• 50 kJ

• 200 kJ

Tags

NGSS.HS-PS1-4

A reactant reaches the transition state

• only when enzymes are used

• when it is ready to receive energy

• after releasing free energy

• when there is an input of energy to initiate the reaction

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1