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Worksheets

Balancing Chemical Equations

Total questions: 40

Worksheet time: 1hrs 2mins

Name
Class
Date
1.
Balance this equation:
____ P+ ____ O---> ____ P2O3
a)
it is already balanced
b)
2, 1, 3
c)
1, 2, 3
d)
1, 3, 2
2.
Balance this equation:
____ CF+ ____ Br---> ____ CBr+ ____ F2
a)
2,1,2,1
b)
1,2,2,1
c)
1,2,1,2
d)
2,2,2,2
3.
Balance this equation:
____ Al +____ HCl ---> ____ H+ ____ AlCl3
a)
2, 6, 3, 2
b)
it is already balanced
c)
4, 12, 3, 4
d)
2, 1, 4, 5
4.
Balance this equation:
____ Mg + ____ Cl---> ____ MgCl2
a)
1, 2,1
b)
already balanced
c)
2,1,1
d)
1,1,2
5.
Balance this equation:
____ SeCl+ ____ O---> ____ SeO+ ____ Cl2
a)
1,2,1,2
b)
1,1,1,3
c)
1,2,1,1
d)
2,1,1,1
6.
Balance this equation:
____ K + ____ Cl2 --->____ KCl
a)
1,1,1
b)
1,1,2
c)
2,1,2
d)
2,2,4
7.
Balance this equation:
____ Na3PO4 + ____ KOH --->____ NaOH + ____ K3PO4
a)
1,2,1,2
b)
1,3,3,1
c)
1,1,1,1
d)
2,6,6,2
8.
Balance this equation:
____ SO2 + ____ Li2Se --->____ SSe2 + ____ Li2O
a)
1,2,1,2
b)
1,4,1,4
c)
1,1,1,1
d)
1,3,1,4
9.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
a)
balanced
b)
unbalanced
10.
What coefficient should be used to make the following equation balanced?
N2+O2--> _NO 
a)
1
b)
2
c)
3
d)
4
11.
Balance this equation
_Al +_HCl --> _H+_AlCl3
a)
2, 6, 3, 2
b)
it is already balanced
c)
4, 12, 3, 4
d)
2, 1, 4, 5
12.
Balance this equation.
_CH4 + _O--> _CO+ _H2O
a)
1,2,1,1
b)
2,1,2,1
c)
1,2,1,2
d)
0,2,0,2
13.
What are the smaller numbers that you CANNOT change in a chemical equation? 
a)
Coefficient
b)
Products
c)
Reactants
d)
Subscript
14.
What are the larger numbers that you CAN CHANGE in a chemical equation? 
a)
Coefficient 
b)
Products
c)
Reactants
d)
Subscripts
15.
How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl2 + H2
a)
1
b)
2
c)
3
d)
4
16.
What law governs the balancing of chemical equations? 
a)
Law of Energy
b)
Law of Conservation of Matter/Mass
c)
Law of Gravity
d)
Law of Matter Movement 
17.
What does the Law of Conservation of Mass state?
a)
Matter cannot be gained or lost in a chemical reaction.
b)
Matter can only be lost in a chemical reaction.
c)
Matter can only be gained in a chemical reaction.
d)
Matter can be gained and lost in a chemical reaction. 
18.
What is the left part of a chemical equation called...
H2 + O --> H2O
a)
Reactants
b)
Products 
c)
Yields 
d)
Chemical Equation 
19.
What is the right part of a chemical equation called...
H2 + O --> H2O
a)
Reactants
b)
Products 
c)
Yields 
d)
Chemical Equation 
20.
What is the arrow in a chemical equation...
H2 + O --> H2O
a)
Reactants
b)
Products 
c)
Yields 
d)
Chemical Equation 
21.
Balance this equation...
H2 + Cl2 --> HCl
a)
It is balanced 
b)
3H2 + Cl2 --> 6H2Cl
c)
H2 + Cl2 --> 2HCl
d)
I don't know! Oh well.
22.
Balance this equation...
HgO --> 2Hg + O2
a)
It is balanced 
b)
2HgO --> Hg + O2
c)
2HgO --> 2Hg + O2
d)
I don't know...Oh well!
23.
Is this balanced?...
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
24.
Balance this equation...
Sb2S3 + O2 --> Sb + SO2
a)
It is balanced
b)
Sb2S3 + 3O2 --> 2Sb + 3SO2
c)
Sb2S3 + O2 --> 2Sb + SO2
d)
I don't know...Oh well!
25.
In the equation,          2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
26.
Why is the following chemical equation not balanced?
H2 + O2 --> H2O
a)
each side of the equation has a different number of oxygen atoms
b)
each side of the equation has a different number of hydrogen atoms
c)
each side has the same mass
27.
What are the REACTANTS :
H2O + CO2 → HCO + HO
a)
H2O and CO2
b)
HCO and HO
c)
H2O ONLY
d)
HCO ONLY
28.
Which of the following are PRODUCTS?
H2O + CO→ HCO + HO
a)
H2O and CO2
b)
HCO and HO
c)
H2O ONLY
d)
HCO ONLY
29.
Is the following equation balanced? 
CH4 + 2O2 → CO2 + 2H2
a)
yes
b)
no
c)
impossible to tell
d)
need more information 
30.
Which number should go in the blank?
_ H2 + O2 -> 2 H2O
a)
1
b)
2
c)
3
d)
0
31.
Which number should go in the blank?
2 Na+ _ Cl2 -> 2 NaCl
a)
1
b)
2
c)
3
d)
0
32.
Which number should go in the blank?
2 Na+ _ Cl2 -> 2 NaCl
a)
1
b)
2
c)
3
d)
0
33.
 Mg  +  ___ HCl  →   MgCl2  +   H2
a)
1
b)
2
c)
3
d)
4
34.
Balance this equation:
 2Li + Cl2 -> LiCl
a)
2Li + Cl2 -> 4LiCl2
b)
2Li + Cl2 -> LiCl2
c)
2Li + Cl2 -> 2LiCl
35.
True or False: When balancing chemical equations the subscripts can change.
a)
true
b)
false
36.
Which of the following is an unbalanced equation?
a)
CaCO--> CaO + CO2
b)
PbO+ 2H2-->2Pb + H2O
c)
2Na+ 2H2O-->2NaOH + H2
d)
CS+ 2O--> CO+ 2SO2
37.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O--> 2AlO3
a)
2
b)
6
c)
1
d)
4
38.
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.
39.
Is this equation balanced?
a)
yes
b)
no
c)
Not enough information
40.
Is this equation balanced?
a)
yes
b)
no
c)
Not enough information