10-1 Chemical Kinetics

Which sample of HCl(aq) reacts at the fastest rate with a 1.0-gram sample of iron filings?

• 10 mL of 1 M HCl(aq) at 10°C

• 10 mL of 1 M HCl(aq) at 25°C

• 10 mL of 3 M HCl(aq) at 10°C

• 10 mL of 3 M HCl(aq) at 25°C

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NGSS.HS-PS1-5

During a laboratory activity to investigate reaction rate, a student reacts 1.0-gram samples of solid zinc with 10.0-milliliter samples of HCl(aq). The table below shows information about the variables in five experiments the student performed. Which two experiments can be used to investigate the effect of the concentration of HCl(aq) on the reaction rate?

• 1 and 3

• 1 and 5

• 4 and 2

• 4 and 3

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NGSS.HS-PS1-5

For a given chemical reaction, the addition of a catalyst provides a different reaction pathway that

• decreases the reaction rate and has a higher activation energy

• decreases the reaction rate and has a lower activation energy

• increases the reaction rate and has a higher activation energy

• increases the reaction rate and has a lower activation energy

Each of four test tubes contains a different concentration of HCl(aq) at 25°C. A 1-gram cube of Zn is added to each test tube. In which test tube is the reaction occurring at the fastest rate?

• 1

• 2

• 3

• 4

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NGSS.HS-PS1-5

A 5.0-gram sample of zinc and a 50.-milliliter sample of hydrochloric acid are used in a chemical reaction. Which combination of these samples has the fastest reaction rate?

• a zinc strip and 1.0 M HCl(aq)

• a zinc strip and 3.0 M HCl(aq)

• zinc powder and 1.0 M HCl(aq)

• zinc powder and 3.0 M HCl(aq)

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NGSS.HS-PS1-5

Adding a catalyst to a chemical reaction results in

• a decrease in activation energy and a decrease in the reaction rate

• a decrease in activation energy and an increase in the reaction rate

• an increase in activation energy and a decrease in the reaction rate

• an increase in activation energy and an increase in the reaction rate

Which conditions will increase the rate of a chemical reaction?

• decreased temperature and decreased concentration of reactants

• decreased temperature and increased concentration of reactants

• increased temperature and decreased concentration of reactants

• increased temperature and increased concentration of reactants

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NGSS.HS-PS1-5

Given the reaction at equilibrium: N₂(g) + 3H₂(g) ⇌ 2NH₃(g). Increasing the concentration of N₂(g) will increase the forward reaction rate due to

• an increase in the number of effective collisions

• a decrease in the number of effective collisions

• a decrease in the activation energy

• an increase in the activation energy

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NGSS.HS-PS1-5

A 1-cubic-centimeter cube of sodium reacts more rapidly in water at 25°C than does a 1-cubic-centimeter cube of calcium at 25°C. The difference in rate of reaction is most closely associated with the different

• surface area of the metal cubes

• nature of the metals

• density of the metals

• concentration of the metals

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NGSS.HS-PS1-5

A chemical reaction occurs when reactant particles

• are separated by great distances

• have no attractive forces between them

• collide with proper energy and proper orientation

• convert chemical energy into nuclear energy

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NGSS.HS-PS1-5