Reactions and Catalysts

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

Crushing a solid into a powder will increase reaction rate because:

• the particles will collide with more energy

• the orientation of colliding particles will be improved

• the activation energy barrier will be lowered

• the powdered form has more surface area

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NGSS.HS-PS1-5

A lump of ignited charcoal which is glowing in air burns more vigorously when lowered into a bottle of pure oxygen. This is due to an increase in

• surface area

• temperature

• concentration

• volume

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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.

Which of the following increases the reaction rate?

• less surface area

• lower temperature

• more particle size

• increased concentration

Tags

NGSS.HS-PS1-5