Understanding Reaction Rates and Energy

Which of the following factors does NOT affect the rate of a chemical reaction?

• Temperature

• Concentration of reactants

• Color of reactants

• Surface area of reactants

Tags

NGSS.HS-PS1-5

What is the role of a catalyst in a chemical reaction?

• It increases the activation energy required for the reaction.

• It decreases the activation energy required for the reaction.

• It changes the products of the reaction.

• It is consumed in the reaction.

Tags

NGSS.HS-PS1-4

Which of the following is a characteristic of an endothermic reaction?

• It releases heat to the surroundings.

• It absorbs heat from the surroundings.

• It does not involve any heat exchange.

• It always occurs spontaneously.

Tags

NGSS.HS-PS1-4

In an exothermic reaction, the energy of the products is:

• Greater than the energy of the reactants.

• Less than the energy of the reactants.

• Equal to the energy of the reactants.

• Unrelated to the energy of the reactants.

Tags

NGSS.HS-PS1-4

Which of the following graphs correctly represents an endothermic reaction?

• A graph where the energy of the products is lower than the energy of the reactants.

• A graph where the energy of the products is higher than the energy of the reactants.

• A graph with a flat line indicating no energy change.

• A graph with a peak indicating a decrease in energy.

Tags

NGSS.HS-PS1-4

What is the activation energy of a reaction?

• The total energy released by the reaction.

• The energy required to start a reaction.

• The energy difference between reactants and products.

• The energy absorbed by the surroundings.

Tags

NGSS.HS-PS1-5

How do enzymes affect the rate of biochemical reactions?

• They increase the rate by providing energy to the reaction.

• They decrease the rate by increasing the activation energy.

• They increase the rate by lowering the activation energy.

• They have no effect on the rate of reactions.

Tags

NGSS.HS-PS1-5

Which of the following statements is true about exothermic and endothermic reactions?

• Exothermic reactions absorb energy, while endothermic reactions release energy.

• Both exothermic and endothermic reactions release energy.

• Exothermic reactions release energy, while endothermic reactions absorb energy.

• Both exothermic and endothermic reactions absorb energy.

Tags

NGSS.HS-PS1-4