Rates of Reaction

What is a chemical reaction?

A process that occurs when chemicals come together to form new substances.

What are reactants?

The chemicals that are present at the start of a chemical reaction and undergo change.

What is a product in a chemical reaction?

The new substance formed as a result of a chemical reaction.

What does collision theory state?

For a chemical reaction to occur, the particles in the reactants must collide with each other.

What is the rate of reaction?

A measure of how fast a chemical reaction occurs.

Name three factors that influence the rate of a chemical reaction.

Temperature, surface area of reactants, and concentration of reactants.

How does increasing temperature affect the rate of reaction?

Heat gives particles more energy, causing them to move faster and collide more frequently, resulting in a faster reaction.

How does increasing reactant concentration affect the rate of reaction?

It increases the number of particles present, which leads to more frequent collisions and a faster reaction rate.

What is surface area in the context of chemical reactions?

A measure of how much of a substance is exposed for potential collisions.

How does increasing surface area affect the rate of reaction?

It provides more area for collisions to occur, which increases the rate of reaction.

What is a catalyst?

A substance that speeds up the rate of a chemical reaction without being consumed.

What catalyst is used to speed up the decomposition of hydrogen peroxide?

Manganese dioxide.

What are the products of the decomposition of hydrogen peroxide?

Water and oxygen.

How can you test for the presence of oxygen gas?

Oxygen will relight a glowing splint.

How is carbon dioxide typically produced in a lab setting?

By reacting an acid (such as hydrochloric acid) with a carbonate (such as calcium carbonate).

What are the products of the reaction between hydrochloric acid and calcium carbonate?

Calcium chloride, water, and carbon dioxide.

How can you test for the presence of carbon dioxide gas?

It will extinguish a lit splint.

What is an exothermic reaction?

A reaction that releases heat to the surroundings, causing the temperature to increase.

What is an endothermic reaction?

A reaction that absorbs heat from the surroundings, causing the temperature to decrease.

What is an energy profile diagram?

A diagram used to show energy transfers during a chemical reaction.

What is activation energy?

The minimum amount of energy required to start a chemical reaction.

What is a helpful mnemonic for remembering exothermic vs endothermic reactions?

Exothermic means heat exits; Endothermic means heat enters.

What is a recommended strategy for answering multiple-choice exam questions?

Use the process of elimination by starting with the answers you are sure of and crossing them off.