Reaction Rates and Catalyst

It is generally believed that catalysts increase reaction rates by:

• removing the activation energy barrier

• providing an alternate activation energy barrier that is lower than the original barrier

• lowering the activation energy barrier

• giving the reacting particles more energy, thus there will be more successful collisions

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NGSS.HS-PS1-5

How does a catalyst work in speeding up a reaction?

• by lowering the activation energy (minimum energy needed for the reaction to take place)

• by giving the reactants more energy

• by increasing the number of reactant particles

• by increasing the temperature

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NGSS.HS-PS1-4

The rate of a chemical reaction normally

• increases as temperature decreases.

• decreases when a catalyst is added.

• increases as reactant concentration increases.

• decreases as reactant concentration increases.

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NGSS.HS-PS1-5

What happens to a catalyst in a reaction?

• It remains unchanged.

• It is incorporated into the reactants.

• It is incorporated into the products.

• It evaporates.

Which out of the following is NOT a factor that affects the rate of a reaction

• temperature

• concentration

• surface area

• volume

• catalysts

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NGSS.HS-PS1-5

Why does a higher concentration increase the rate of reaction?

• it increases the amount of reactants

• it lowers the activation energy

• it increases the energy of particle collisions

• it increases the frequency of particle collisions

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NGSS.HS-PS1-5

What makes an effective collision?

• When molecules collide.

• When molecules collide with the proper orientation.

• When molecules collide with proper orientation and enough kinetic energy.

• High Temperature.

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NGSS.HS-PS2-3

Which of the following increases the reaction rate?

• less surface area

• lower temperature

• more particle size

• increased concentration

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NGSS.HS-PS1-5

List four factors that affects the rate of a reaction

• temperature

• concentration

• surface area

• volume

• catalysts

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NGSS.HS-PS1-5

The following graph shows two different reaction pathways for the same overall reaction at the same temperature. Which pathway is slower and why?

• Red, because the activation energy is larger

• Blue, because the activation energy is lower

• both reaction progress at the same rate

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NGSS.HS-PS1-4