Quiz about 8th Grade 3.2 Chemical Reactions Test Review

Question 1

Energy is required to break chemical bonds.

Accepted Answer

True

Answer

False

Question 2

Mass is sometimes lost during a chemical reaction.

Accepted Answer

False

Answer

True

Question 3

Biological catalysts are called products.

Accepted Answer

False

Answer

True

Question 4

Products have different properties compared to reactants.

Accepted Answer

True

Answer

False

Question 5

Increasing the temperature generally decreases the reaction rate.

Accepted Answer

False

Answer

True

Question 6

To increase the reaction rate, you should increase the concentration of the reaction in the rate-determining (slow) step.

Accepted Answer

True

Answer

False

Question 7

A new substance that is formed following a chemical reaction is

Accepted Answer

product

Answer

catalyst

Answer

activation energy

Answer

inhibitor

Question 8

A reaction that occurs when a substance reacts with oxygen is

Accepted Answer

combustion reaction

Answer

endothermic reaction

Answer

exothermic reaction

Answer

reactant

Question 9

A substance that is present before a chemical reaction that then undergoes changes during a chemical reaction is

Accepted Answer

reactant

Answer

catalyst

Answer

product

Answer

inhibitor

Question 10

A chemical reaction that releases heat is

Accepted Answer

exothermic reaction

Answer

endothermic reaction

Answer

combustion reaction

Answer

reactant

Question 11

A substance that increases the reaction rate without being permanently changed is

Accepted Answer

catalyst

Answer

activation energy

Answer

reactant

Answer

product

Question 12

A chemical reaction that absorbs heat is called

Accepted Answer

endothermic reaction

Answer

combustion reaction

Answer

exothermic reaction

Answer

reactant

Question 13

A substance used to slow down or stop a chemical reaction is

Accepted Answer

inhibitor

Answer

catalyst

Answer

product

Answer

reactant

Question 14

The minimum amount of energy that is required to start a chemical reaction is

Accepted Answer

activation energy

Answer

product

Answer

catalyst

Answer

endothermic reaction

Question 15

All chemical reactions involve a change in energy.

Accepted Answer

True

Answer

False

Question 16

When balancing a chemical equation, it is acceptable to change the subscripts in formula.

Accepted Answer

False

Answer

True

Question 17

To increase the rate of reaction, what factor must be increased?

Accepted Answer

all of the above

Answer

temperature

Answer

surface area

Answer

concentration

Question 18

What forms of energy are either released or absorbed during a chemical reaction?

Accepted Answer

all of the above

Answer

light and sound

Answer

thermal energy

Answer

electrical energy

Question 19

What are indicators that a reaction has occurred?

Accepted Answer

formation of gas, odor, color change, formation of precipitate, release of energy in form of light and sound

Answer

change in color, formation of precipitate, formation of gas, change in mass

Answer

change in color, release of energy in form of light or sound, change in mass

Answer

formation of precipitate, odor, change in mass

Question 20

Is freezing liquid water to form ice a chemical or physical change? Why?

Accepted Answer

It is a physical change because molecules are not transformed into a different substance.

Answer

It is a chemical change because the molecules are transformed into a different substance.

Answer

It is both a physical and chemical change because the molecules are transformed into a different substance.

Answer

None of the above

Question 21

Molecules must collide with enough force and in the proper orientation to react with one another.

Accepted Answer

True

Answer

False

Question 22

Why does powdered grain ignite at a faster rate than a solid grain block?

Accepted Answer

Powdered grain has a larger surface area, increasing reaction rate.

Answer

Powdered grain has a smaller surface area, increasing reaction rate.

Answer

Powdered grain has a higher temperature, increasing reaction rate.

Answer

Powdered grain is a catalyst, increasing reaction rate.

Question 23

What is a synthesis reaction?

Accepted Answer

a reaction where two or more substances combine to form a product

Answer

a reaction where a substance is broken down into two or more products

Answer

a reaction that occurs when a substance reacts with oxygen

Question 24

$$A\ +\ BC\ \rightarrow\ AC\ +\ B$$ is an example of what type of reaction?

Accepted Answer

single replacement

Answer

Synthesis

Answer

decomposition

Answer

double replacement

Question 25

$$2AgO\left(s\right)\ \rightarrow4Ag\left(s\right)+O\left(g\right)$$ is an example of what kind of reaction?

Accepted Answer

decomposition

Answer

synthesis

Answer

single replacement

Answer

double replacement

Question 26

$$K\left(s\right)+MgBr\left(aq\right)\rightarrow KBr\left(aq\right)+Mg\left(s\right)\ $$ is an example of what type of reaction?

Accepted Answer

single replacement

Answer

synthesis

Answer

decomposition

Answer

double replacement

Question 27

$$2Mg\left(s\right)+O\left(g\right)\rightarrow2MgO\left(s\right)$$ is an example of what type of reaction?

Accepted Answer

synthesis

Answer

decomposition

Answer

single replacement

Answer

double replacement

Question 28

$$Pb\left(OH\right)\left(aq\right)+2HCl\left(aq\right)\rightarrow2HO\left(l\right)+PbCl\left(s\right)$$ is what type of reaction?

Accepted Answer

double replacement

Answer

synthesis

Answer

decomposition

Answer

single replacement

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