wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Gr 8 Review Qns Useful Chemical Reactions

Total questions: 70

Worksheet time: 3hrs 31mins

Name
Class
Date
1.

Method or means of changing one or more chemicals or chemical compounds

a)

Chemical Process

b)

Chemical Reaction

c)

Molecule

d)

Properties

2.

The smallest particle of an element; made of electrons, protons, and neutrons

a)

Atoms

b)

Elements

c)

Molecules

d)

Products

3.

The process by which one or more substances change to produce one or more different substances

a)

Chemical Process

b)

Reactant

c)

Chemical Reaction

4.

The simplest unit of a chemical compound that can exist; formed when two or more atoms join together chemically

a)

Atom

b)

Compound

c)

Molecule

5.

A solid that is deposited from a solution

a)

Solid

b)

Liquid

c)

Product

d)

Precipitate

6.

A substance produced during a chemical reaction

a)

Product

b)

Reactant

c)

Properties

7.

Physical and chemical characteristics of matter used to describe or identify a substance

a)

Chemical Reaction

b)

Properties

c)

Product

8.

A substance that takes part in and undergoes change during a reaction

a)

Product

b)

Molecule

c)

Reactant

9.

A new substance with unique chemical and physical properties that is formed when two or more elements are chemically bonded during a chemical reaction

a)

Product

b)

Compound

c)

Molecule

d)

Atom

10.

A chemical reaction or process that releases heat.

a)

Endothermic

b)

Exothermic

11.

What are the atoms of each element in this chemical formula 2Na2SO4

a)

2 Na, 0 S, 4 O

b)

2 Na, 1 S, 4 O

c)

4 Na, 1 S, 4 O

d)

4 Na, 2 S, 8 O

12.

How many atoms of each element on the reactant side of the equation?

a)

4 C, 6 H, 14 O

b)

2 C, 6 H, 2 O

c)

4 C, 12 H, 7 O

d)

4 C, 12 H, 14 O

13.

A chemical change is different than a physical change because in a chemical change

a)

chemicals are used

b)

molecules do not physically touch

c)

a new substance is formed and in a physical no new substance is formed

d)

the change can be seen but in a physical change it cannot

14.

Which of the following 2 are chemical reactions?

a)

sugar dissolving in water

b)

water turning into steam

c)

burning wood

d)

mixing baking soda and vinegar

e)

tearing paper

15.

How many Carbons are present on the reactant side?

a)

1

b)

2

c)

3

d)

4

16.

How many Hydrogens are on the product side of this chemical equation?

a)

1

b)

2

c)

3

d)

4

17.

How many Oxygens are on the product side of this chemical equation?

a)

1

b)

2

c)

3

d)

4

18.

Why are chemical equations always balanced? Select ALL that apply.

a)

Matter cannot be created.

b)

Matter cannot be destroyed.

c)

Matter can only be rearranged/conserved.

d)

Matter doesn't matter.

19.

In a chemical reaction, if the reactants are heated, the reaction usually happens

a)

slower

b)

faster

c)

at the same rate

d)

in a smaller volume

20.

Some chemical reactions require a substance called a catalyst. The purpose of a catalyst is

a)

to warm up the reaction

b)

to speed up the reaction

c)

to create more reactants

d)

to stop the reaction

21.

Is this chemical equation balanced? Why or why not? Choose the BEST answer.

a)

Yes, the amount of atoms for each element are equal on both the reactant and product side.

b)

No, the carbons are not the same number on both the reactant and product side.

c)

No, neither the carbons or hydrogens are the same amount on both the reactant and product side.

d)

No, none of the elements (carbon, hydrogen, or oxygen) are the same amount on both the reactant and product side.

22.

Which of the following is a common sign that a chemical change has occurred?

a)

A chemical has turned a different color, bubbled, and/or changed temperature.

b)

A chemical has changed to a different state of matter, such as a liquid to a solid.

c)

A chemical has changed size.

d)

A chemical has become a different shape.

23.

a process in which atoms rearrange to form new substances

a)
chemical reaction
b)
physical reaction
c)
biological reaction
d)
nuclear reaction
24.

a starting substance that is part of a chemical reaction

a)
catalyst
b)
product
c)
reactant
d)
inhibitor
25.
Breaking down a substance into simpler substances
a)
Displacement
b)
Synthesis
c)
Decomposition
d)
Oxidation
26.

Identify the following chemical reaction.

2 NaBr + 1 Ca(OH)2 ----> 1 CaBr2 + 2 NaOH

a)

Synthesis (or combination)

b)

Decomposition

c)

Single displacement

d)

Double displacement

27.

Identify the following chemical reaction.

3 HBr + 1 Al(OH)3 ----> 3 H­2O + 1 AlBr3

a)

Synthesis (or combination)

b)

Decomposition

c)

Single displacement

d)

Double displacement

28.

Identify the following chemical reaction.

Pb + FeSO4 ----> PbSO4 + Fe

a)

Synthesis (or combination)

b)

Decomposition

c)

Single displacement

d)

Double displacement

29.

What reaction has the following general formula:

AB --> A + B

a)

Synthesis

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

30.

What reaction has the following general formula:

A + CD --> C + AD

a)

Synthesis

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

31.

What reaction has the following general formula:

A + B --> AB

a)

Synthesis

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

32.

Which chemical reaction always starts with a hydrocarbon that reacts with oxygen and produces carbon dioxide and water?

a)

Decomposition

b)

Synthesis

c)

Combustion

d)

Single Replacement

33.

Which phrase describes what happens to atoms in a chemical reaction?

a)

never lost or gained, just rearranged

b)

sometimes lost, never rearranged

c)

sometimes lost, gained, or rearranged

d)

lost or gained, never rearranged

34.

In a chemical reaction, everything to the right of the arrow are called ______________.

a)
Products
b)
Yields
c)
Molecules
d)
Reactants
35.
What type of reaction is the equation C + O2 → CO2?
a)
Synthesis Reaction
b)
Decomposition Reaction
c)
Single Displacement Reaction
d)
Double Displacement Reaction
36.
What type of reaction is the equation 2NaCl →2Na +Cl2?
a)
Synthesis Reaction
b)
Decomposition Reaction
c)
Single Displacement Reaction
d)
Double Displacement Reaction
37.
Cu + 2Ag(NO3) → 2Ag + Cu(NO3)
a)
Synthesis Reaction
b)
Decomposition Reaction
c)
Single Displacement Reaction
d)
Double Displacement Reaction
38.

Consider the chemical equation CH4 + 2 O2 → CO2 + 2 H2O. What type of reaction is this?

a)

Synthesis

b)

Combustion

c)

Double Replacement

d)

Decomposition

39.

What are the reactants in the chemical equation pictured?

a)

CH4 and CO2

b)

CH4 and O2

c)

CO2 and H2O

d)

O2 and H2O

40.

2Na +S → Na2S

a)

Double Replacement

b)

Decomposition

c)

Combustion

d)

Synthesis

41.

2 NO2 ---> 2 O2 + N2

a)

Synthesis

b)

Single Replacement

c)

Decomposition

d)

Combustion

42.

What reaction has the following general formula:
CxHy + O2 −>CO2 + H2OC_xH_y\ +\ O_2\ ->CO_{2\ }+\ H_2O  

a)

Combination

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

e)

Combustion

43.
PbCl2 + AgNO3 ---> Pb(NO3)2 + AgCl 
a)
Synthesis
b)
Decomposition
c)
Single Replacement
d)
Double Replacement
44.
NH3 + HCl ---> NH4Cl 
a)
Synthesis
b)
Decomposition
c)
Single Replacement
d)
Double Replacement
45.
In a chemical reaction, everything to the right of the arrow is called ______________.
a)
Products
b)
Yields
c)
Molecules
d)
Reactants
46.
In the equation,          2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
47.
AB →A + B
a)
Decomposition
b)
Single Replacement
c)
Double Replacement
d)
Synthesis
48.
Which generalized equation represents a synthesis reaction?
a)
A + BC → AC+ B
b)
A + B → AB
c)
AB → A + B
49.

What is the laboratory test for Oxygen?

a)

Puts out a glowing splint

b)

Makes a squeaky pop sound with a burning splint

c)

Relights a glowing splint

50.

What is the most abundant (this means lots of it) gas in Earth's atmosphere?

a)

Nitrogen

b)

Argon

c)

Oxygen

d)

Carbon Dioxide

51.

Which gas is used to make fizzy drink

a)

Nitrogen

b)

Oxygen

c)

Carbon dioxide

d)

Helium

52.

Which gas is used as fertilizer?

a)

Argon

b)

Helium

c)

Nitrogen

d)

Oxygen

53.

Which gas is used in balloons?

a)

Helium

b)

Argon

c)

Neon

d)

Krypton

54.

Living things use oxygen for the process of

a)

Respiration

b)

Hearing

c)

Digestion

d)

Walking

55.

Which gas supports burning?

a)

Helium

b)

Argon

c)

Neon

d)

Oxygen

56.

Combustion cannot take place without

a)

water

b)

nitrogen

c)

helium

d)

oxygen

57.

What is the test to prove the presence of oxygen?

a)

Add a lit splint and it relights

b)

Add a lit splint and it burns with a pop

c)

Add a glowing splint and it relights

d)

Add a glowing splint and it burns with a pop

58.

Which gas "explodes" and gives you a squeaky pop?

a)

hydrogen

b)

oxygen

c)

carbon dioxide

59.

Which gas(es) could I test for with a glowing splint?

a)

hydrogen

b)

oxygen

c)

carbon dioxide

60.

Which gas can suffocate a lit splint?

a)

hydrogen

b)

oxygen

c)

carbon dioxide

61.

Which gas has the chemical property of reacts with limewater to make a solid precipitate?

a)

hydrogen

b)

oxygen

c)

carbon dioxide

62.

Which of the following is the most likely clue that a reaction has created a gas?

a)

you can smell it

b)

the container gets hot

c)

the container gets cold

d)

bubbles form in liquid solution

63.

Physical or Chemical Change: You cut your hair?

a)

physical change

b)

chemical change

64.

Physical or Chemical Change: mixing salt and water?

a)

physical change

b)

chemical change

65.

Physical or Chemical Change: an aspirin is crushed into fine powder?

a)

physical change

b)

chemical change

66.
What is the word equation for the reaction between hydrochloric acid and sodium hydroxide?
a)

Hydrochloric acid + sodium hydroxide → sodium chloride + water

b)

Sodium hydroxide + hydrochloric acid → sodium oxide + water

c)

Water + sodium chloride → sodium hydroxide + hydrochloric acid

d)

Sodium chloride + water → hydrochloric acid + sodium hydroxide

67.
What is the word equation for the reaction between sulfuric acid and potassium hydroxide?
a)

Sulfuric acid + potassium hydroxide → potassium sulfate + water

b)

Potassium oxide + sulfuric acid → potassium sulfate + water

c)

Water + potassium sulfate → potassium hydroxide + sulfuric acid

d)

Potassium sulfate + water → sulfuric acid + potassium hydroxide

68.
What is the word equation for the reaction between acetic acid and barium hydroxide?
a)

acetic acid + barium hydroxide → sodium acetate + water

b)

barium hydroxide + acetic acid → barium acetate + water

c)

water + barium acetate → barium hydroxide + acetic acid

d)

potassium acetate + water → acetic acid + barium hydroxide

69.
Write a symbol equation for the neutralization of hydrochloric acid with sodium hydroxide.
a)

HCl + NaOH → NaCl + H2OH_2O

b)

HCl + NaOH → NaCl + H2H_2

c)

HCl + NaOH → NaCl + 2 H2OH_2O

d)

HCl + NaOH → Na2Cl + H2ONa_2Cl\ +\ H_2O

70.

What is the pH of a neutral solution?

a)

14

b)

1

c)

0

d)

7

Similar Resources on Wayground

Science 8 Review (Chemistry) - DepEd

70 questions

Science 8 Review (Chemistry) - DepEd

quiz

Worksheet

•

6th - 8th Grade

Intro to Physical Science

71 questions

Intro to Physical Science

quiz

Worksheet

•

8th - 12th Grade

S8P1_Matter_Cumulative Unit Exam_22-23

67 questions

S8P1_Matter_Cumulative Unit Exam_22-23

quiz

Worksheet

•

5th - 8th Grade

Physical & Chemical Properties Test Review

70 questions

Physical & Chemical Properties Test Review

quiz

Worksheet

•

6th - 8th Grade

Ch6 Test Review (Covalent Compounds)

75 questions

Ch6 Test Review (Covalent Compounds)

quiz

Worksheet

•

KG - University

Introduction to Chemical Bonds

66 questions

Introduction to Chemical Bonds

quiz

Worksheet

•

8th Grade

Chemistry Test Review

74 questions

Chemistry Test Review

quiz

Worksheet

•

8th Grade

Materials: Metals and Non-Metals– 2_1

70 questions

Materials: Metals and Non-Metals– 2_1

quiz

Worksheet

•

8th - 10th Grade