Kinetics

Limestone chunks are reaction with hydrochloric acid solution at constant temperature with average speed. If we crash the chunks of limestone into powder how would speed of reaction change?

• Reaction speeds up

• Reaction does not change

• Reaction slows down

• Reaction stops

Tags

NGSS.MS-PS1-2

Reaction rate means...

• amount of product formed

• speed of reaction

• concentration of reacting particles

• combining reactants with products

Tags

NGSS.HS-PS1-5

Decreasing the particle size increases the reaction rate because

• It makes particles move faster

• It increases the likelihood of collisions with the correct geometry

• It decreases the surface area available to react

• It increases the number of collisions

Tags

NGSS.HS-PS1-5

The catalyst alters the rate of a chemical reaction by,

• providing an alternative pathway with a lower Ea

• changing the products formed in the direction of the reaction

• providing a surface on which the molecules react

• increasing the frequencies of collisions between molecules

Tags

NGSS.HS-PS1-5

During a science fair, Abigail, Evelyn, and Priya conducted an experiment to observe the rate at which a sugar cube dissolves in water at room temperature. What is the unit of the reaction rate they observed?

• Molarity (M)

• Molarity per second (M/s)

• Kelvin (K)

• Joules (J)

Answer explanation

The unit of reaction rate in a chemical reaction is Molarity per second (M/s), which represents the change in concentration of reactants or products per unit time.

Why does a higher surface area of a solid reactant increase the reaction rate?

• It increases the density of the reactant

• It decreases the path length for diffusion

• It increases the number of available reactive sites

• It increases the activation energy required for the reaction

• 0 order reaction

• 1st order reaction

• 2nd order reaction

• 3rd order reaction

Tags

NGSS.HS-PS1-5

What is the significance of the activation energy in a chemical reaction?

• It is the energy released during the reaction

• It is the minimum energy required for reactants to transform into products

• It determines the color of the reaction mixture

• It is the energy required to break bonds in the products

Crushing a solid catalyst into finer particles before adding it to a reaction mixture will:

• Decrease the reaction rate.

• Have no effect on the reaction rate.

• Increase the reaction rate.

• Stop the reaction.

Answer explanation

Increasing the surface area of a solid reactant will increase the reaction rate by providing more area for collisions between reactant particles.

Tags

NGSS.HS-PS1-5

In a chemical reaction, if the concentration of reactants is increased, what happens to the reaction rate?

• It decreases

• It increases

• It remains unchanged

• It initially increases, then decreases

Tags

NGSS.HS-PS1-5