HESI A2 test Chemistry - Reaction Rates, Equilibrium, And Reversibility

What is the effect of increasing temperature on the rate of a chemical reaction?

The reaction rate increases.

Why does a higher concentration of reactants generally lead to a faster reaction rate?

It increases the likelihood of collisions between reactant particles.

How does increasing the surface area of reactants affect a chemical reaction?

It increases the rate of the reaction.

What happens when a catalyst is added to a chemical reaction?

The activation energy is reduced, increasing the reaction rate.

How does a decrease in the concentration of reactants affect the reaction rate?

The reaction rate decreases.

What occurs when reactant particles collide with insufficient energy?

The reaction does not occur.

What is the effect of using a powdered solid reactant rather than large chunks of the same solid?

The reaction rate increases.

In the context of reaction rates, what does the term “activation energy” refer to?

The energy required to start a reaction

In the Alka-Seltzer experiment, why does a crushed tablet dissolve faster than a whole tablet?

It has a larger surface area for the reaction with water.

What effect does increasing the temperature have on the rate of the Elephant’s Toothpaste reaction?

The reaction rate increases.

In the Elephant’s Toothpaste reaction, how does using a more concentrated hydrogen peroxide solution affect the reaction?

It increases the amount of foam produced.

In the Alka-Seltzer experiment, why does the reaction occur faster in warm water compared to cold water?

Warm water increases the kinetic energy of reactant particles.

In which of the following cases will the reaction rate be the slowest?

Low temperature, small surface area

How does increasing the temperature affect the activation energy of a reaction?

It does not affect the activation energy.

Why does food spoil faster when left out at room temperature compared to being stored in the refrigerator?

Higher temperatures increase the kinetic energy of molecules, speeding up reactions.

Why is firewood chopped into smaller pieces before being burned?

Smaller pieces have a greater surface area, which speeds up the reaction.

Why does refrigerating batteries extend their lifespan?

Cold temperatures decrease the rate of chemical reactions inside the battery.

Which combination of conditions would result in sugar dissolving the fastest in water?

Hot water and stirring

Which combination of factors would cause garlic to release its flavor the fastest when cooked?

Chopped garlic and hot oil

In a reaction that involves gases, which combination of conditions would lead to the fastest reaction rate?

High temperature and high pressure