Unit 2 Lesson 6: Chemical Reactions

Question 1

What is rusting?

Answer 1

Rusting is a chemical reaction that occurs between iron and oxygen in the presence of water.

Question 2

What is the exact defintion of a chemical reaction?

Answer 2

a process in which the chemical arrangement of a substance changes

Question 3

What happens during a chemical reaction?

Answer 3

During a chemical reaction, a new substance forms from the reacting substances. Bonds between atoms break and atoms are rearranged to form new substances.

Question 4

What happens during rusting?

Answer 4

During rusting, iron and oxygen elements combine to form iron oxide, which is commonly known as rust.

Question 4

What is a chemical equation?

Answer 4

A chemical equation is a model of a chemical reaction. It shows the reacting chemicals and the chemicals that form during a reaction. The arrow in a chemical equation means “yields.”

Question 5

What are reactants?

Answer 5

Reactants are substances that enter a chemical equation.

Question 6

What are products?

Answer 6

The substances that form during the chemical reaction are called the products.

Question 7

What are the inputs and outputs of a chemical equation?

Answer 7

The reactants are the inputs and the products are the outputs.

Question 8

What is the chemical equation for rust?

Answer 8

iron + oxygen → iron oxide

Question 9

What is the balanced chemical equation?

Answer 9

4Fe + 3O2 → 2Fe2O3

Question 10

What does the word exothermic mean using terminology?

Answer 10

The word part exo means “out” so, during an exothermic reaction, more energy is released into the environment than is absorbed.

Question 10

Is cellular resipiation a exothermic reaction if so explain why

Answer 10

Cellular respiration is an exothermic reaction. The body uses some energy during cellular respiration, but a lot more energy is produced in the form of ATP.

Question 11

What is the exact defintion of an exothermic reacion?

Answer 11

occurs when more energy is released by the substance than is absorbed by the substance

Question 11

When does an exothermic reaction occur?

Answer 11

Breaking bonds and forming new bonds requires a change in energy. If the energy required to break the bonds is greater than the energy required to form new bonds, an exothermic reaction occurs.

Question 12

What is the chemical equation for cellular respiration?

Answer 12

glucose+oxygen→carbon dioxide+water+energy=(ATP)

Question 13

Give an example of a endothermic reaction?

Answer 13

When the substances inside a cold pack mix and bind together more energy is absorbed than is released. This causes a drop in temperature in the surrounding environment.

Question 14

What is a endothermic reaction?

Answer 14

An endothermic reaction occurs when more energy is absorbed by the substance than is released into the environment. The word part endo means “inward.”

Question 15

What is the chemical equation for photosynthesis?

Answer 15

carbon dioxide+water+light energy→glucose+oxygen

Question 16

How much energy does exothermic reacions need?

Answer 16

Exothermic reactions need a small amount of energy to activate the reaction but a lot more energy is released in the process.

Question 16

What is activation energy?

Answer 16

Activation energy is the minimum amount of energy the reactants need for a chemical reaction to occur.

Question 17

How much energy does an endothermic reaction need?

Answer 17

During an endothermic reaction the products are at a higher energy state than the reactants.

Question 18

How much energy does activation energy need

Answer 18

Therefore, the activation energy needs to be high for the reaction to occur.

Question 19

What happens to the energy during a chemical reaction?

Answer 19

The total amount of energy gained or lost during reaction is equal to the difference in energy between the reactants and the products.

Question 20

The light and colors produced by fireworks are the result of chemical reactions. Do you think the reactions that produce these lights are exothermic or endothermic? Explain your reasoning.

Answer 20

They are exothermic because light and heat are released during the reaction.

Question 20

The student wants to determine whether an exothermic or endothermic process occurs when a salt is mixed into water. Explain a process the student could use to determine whether an exothermic or an endothermic process takes place.

Answer

Answer 20

The student could use a thermometer to measure whether there is a temperature change when the salt mixes into the water. If the temperature increases, it is an exothermic process. If the temperature decreases, it is an endothermic process.

Question 21

What do enzymes do?

Answer 21

human body has enzymes which are specialized proteins that catalyze or speed up chemical reactions.

Question 22

What can changes to enviroment do to enzymes?

Answer 22

Changes to the environment can denature enzymes. A denatured enzyme can no longer perform its function.

Question 22

What do enzymes do to the bonds between the reactants?

Answer 22

Like most catalysts, enzymes weaken the bonds between the reactants which lower the activation energy of a chemical reaction.