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Chemical Reaction Review

Total questions: 40

Worksheet time: 1hrs 5mins

Name
Class
Date
1.
How many atoms does substance 3 contain?
a)
12
b)
15
c)
8
d)
4
2.
Is the following equation balanced?
a)
No, there are more atoms on the reactant side.
b)
No, there are more atoms on the product side.
c)
Yes, there are equal number of atoms on both sides.
d)
Yes, even though the reactant side has two more atoms.
3.
In an endothermic reaction, heat is ...
a)
taken in or absorbed
b)
given out or released 
4.

Baking bread and cooking an egg absorb energy and are examples of....?

a)

Endothermic processes

b)

Exothermic processess

c)

None of these

5.
Exothermic reactions...
a)
Absorb energy
b)
Release energy
c)
Release Color
d)
Absorb Color
6.
Which of the following shows the correct way to balance the chemical equation?
Fe + O2 -> Fe2O3
a)
4Fe + 3O2 -> 2Fe2O3
b)
2 Fe + 3O2 -> Fe2O6
c)
4 Fe + O6 -> 2Fe2O3
d)
None of the options are correctly balanced.
7.
Balance this equation...
HgO --> Hg + O2
a)
It is balanced 
b)
2HgO --> Hg + O2
c)
2HgO --> 2Hg + O2
d)
I don't know...Oh well!
8.
What happens in ALL chemical changes?
a)
Change in state of matter
b)
A new substance is formed
c)
Bubbles are produced
d)
An explosion
9.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
a)
balanced
b)
unbalanced
10.

In reactions, the number of atoms in the products must be equal to..

a)

the end of the equation.

b)

the Reactants

c)

the Starters

d)

the Enders

11.

According to the law of conservation of mass, how does the amount of each element on the product side compare to each element on the reactant side?

a)

The amount of atoms on each side is equal

b)

The amount of atoms on the product side is greater

c)

The amount of atoms on the reactant side is greater

d)

Depends on the reaction

12.

Balance the following chemical equation:

____KClO3 → ____KCl + ____O2

a)

2KClO3 → 4KCl + O2

b)

4KClO3 → 2KCl + 3O2

c)

2KClO3 → 2KCl + 3O2

13.

Does this equation show that mass is conserved?

C5H10 + O2 --> CO2 + H2O

a)

yes, it is balanced.

b)

no, it is not balanced.

14.

In chemical reactions, what does the Law of Conservation of Mass mean?

a)

Matter is not created or destroyed.

b)

The total mass of the reactants is greater than the total mass of the products.

c)

The total mass of the reactants is less than the total mass of the products.

d)

Matter is not changed.

15.

According to the law of conservation of energy, how does the energy of the product side compare to energy on the reactant side?

a)

The amount of energy on each side is equal

b)

The amount of energy on the product side is greater

c)

The amount of energy on the reactant side is greater

d)

Depends on the reaction

16.

Look at this image. What type of reaction is this?

a)

endothermic

b)

exothermic

17.

On the right side of the equation is the

a)

reactants

b)

products

c)

yield sign

d)

Coefficient

18.

On the left side of the equation is the

a)

reactants

b)

products

c)

yield sign

d)

Coefficient

19.

The arrow in this equation is the

a)

reactants

b)

products

c)

yield sign

d)

Coefficient

20.

The number 2 that is partially below the chemical formula in this equation is the

a)

reactants

b)

products

c)

subscript

d)

Coefficient

e)

yield sign

21.

The NaCl is an example of

a)

chemical equation

b)

chemical formula

c)

chemical reaction

d)

Coefficient

22.

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

a)

Evidence

b)

Chemical Reaction

c)

Substance

d)

Reactants

23.

A solid that is deposited from a solution

a)

Exothermic Reaction

b)

Endothermic Reaction

c)

Precipitate

d)

Product

24.
In the equation,          2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
25.
a chemical reaction that releases energy by light or heat
a)
Endothermic Reaction
b)
Exothermic Reaction
c)
Diffusion
d)
Fission
26.

a process or reaction in which the system absorbs energy from its surroundings causing the temperature to decrease.

a)

Endothermic Reaction

b)

Exothermic Reaction

c)

Diffusion

d)

Fission

27.

the number placed in front of a chemical formula in a chemical equation; represents the number of molecules of that substance.

a)

coefficient

b)

subscript

28.

the number written to the right and slightly below an element in a chemical formula; represents the number of atoms of an element present in a chemical formula.

a)

coefficient

b)

subscript

29.
All of the following reactions are correctly balanced except-
a)
A
b)
B
c)
C
d)
D
30.
What is the mass of H2O in the reaction above?
a)
70.01
b)
24.11
c)
21.44
d)
48.22
31.

How many Al atoms are in this compound? 4Al2O3

a)

2

b)

8

c)

6

d)

4

32.

How many F atoms are in this compound?

6MgF2

a)

2

b)

6

c)

8

d)

12

33.

The equation below represents a chemical reaction that occurs in living cells. Is this an endothermic or exothermic reaction?

a)

endothermic

b)

exothermic

34.

What is the total number of atoms in this chemical formula? C8H3NaBr12C_8H_3NaBr_{12}  

a)

18

b)

12

c)

25

d)

24

35.
How many Oxygen atoms are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
36.
Number of H in 3(NH₄)₂CrO₄
a)
4
b)
2
c)
8
d)
24
37.
Which is the correct formula for:
 three hydrogen (H)
one sulfur (S)
four oxygen (O)
a)
H3SO4
b)
HSO4
c)
H4S3O
d)
H2O
38.

How many atoms are present if there is no subscript following the element symbol?

a)

0

b)

2

c)

only 1

d)

1 million

39.
Which of the following characteristics is shared by all chemical reactions?
a)
Produce a precipitate
b)
Show a color change
c)
Release heat energy
d)
Form new substances
40.

Which of these is NOT a sign that a chemical change has occurred?

a)

The substance breaks apart

b)

An unexpected color change

c)

A temperature change

d)

The formation of a precipitate