Matter and Chemical Change (Topic 7-8)

Question 1

What is the term for an organic-based substance that burns?

Answer 1

Fuel.

Question 2

What type of chemical reaction is characterized by the release of heat?

Answer 2

An exothermic reaction.

Question 3

What are the substances produced as a result of a chemical reaction called?

Answer 3

Products.

Question 4

What is a substance that increases the rate of a chemical reaction without being changed itself?

Answer 4

A catalyst.

Question 5

What is the measure of how fast a chemical reaction occurs called?

Answer 5

Reaction rate.

Question 6

What process occurs when a metal combines with oxygen?

Answer 6

Corrosion.

Question 7

A chemical reaction in which heat is absorbed is known as a(n) _____ reaction.

Answer 7

endothermic

Question 8

What is the process of coating a metal with zinc to prevent corrosion called?

Answer 8

Galvanization.

Question 9

What is the process of using electrolysis to cover one metal with another?

Answer 9

Electroplating.

Question 10

What are the initial substances that go into a chemical reaction called?

Answer 10

Reactants.

Question 11

What is the term for a natural substance that functions as a catalyst in living organisms?

Answer 11

An enzyme.

Question 12

What is the term for a process in which a substance combines with oxygen and releases heat?

Answer 12

Combustion.

Question 13

A process where substances undergo an atomic reorganization to form new substances is called a _____.

Answer 13

chemical reaction

Question 14

What is a substance that slows down the rate of a chemical reaction called?

Answer 14

An inhibitor.

Question 15

What is the single most definitive sign that a chemical change has occurred?

Answer 15

A new substance or substances must be formed.

Question 16

Is it true that changes in colour, temperature, and odour always indicate a chemical reaction has taken place?

Answer 16

No, while they are common indicators, they do not always signify a chemical reaction.

Question 17

When a solid dissolves in a liquid to form a solution, what kind of change usually takes place?

Answer 17

A physical change, not a chemical reaction.

Question 18

Why do exothermic reactions release energy?

Answer 18

Energy is released when new, more stable chemical bonds are formed in the products.

Question 19

What does the human body release to speed up its internal chemical reactions?

Answer 19

Enzymes.

Question 20

What is the chemical name for rust?

Answer 20

Iron oxide.

Question 21

Combustion is almost always an _____ chemical reaction.

Answer 21

exothermic

Question 22

Which group of elements is known to be particularly corrosive?

Answer 22

The halogens.

Question 23

In the chemical reaction 2Mg_(s) + O_2(g) —> 2MgO_(s) + light, identify one of the reactants.

Answer 23

Magnesium (Mg) or oxygen (O₂).

Question 24

In the chemical reaction 2Mg_(s) + O_2(g) —> 2MgO_(s) + light, what is the product?

Answer 24

Magnesium oxide (MgO).

Question 25

In the equation 2Mg_(s) + O_2(g) ---> 2MgO_(s) + light, which element exists as a diatomic molecule?

Answer 25

Oxygen (O₂).

Question 26

What type of reaction realeases more energy than it started with?

Answer 26

Exothermic

Question 27

What are some factors that affect checmical reaction rates?

Answer 27

Temperature, concentration of substances, catalysts, size of pieces (surface area)

Question 28

Where in the human body would you most likely find enzymes aiding in digestion?

Answer 28

In the stomach.

Question 29

What is the primary reason that corrosion is considered an undesirable process?

Answer 29

Corroded materials lose their strength.

Question 30

Sulphur dioxide, carbon monoxide, nitrogen oxide, and soot are all examples of what?

Answer 30

Undesirable products of combustion.