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WorksheetsChemical Equation Questions
Total questions: 54
Worksheet time: 58mins
Name
Class
Date
1.
In a chemical equation, on what side of the arrow are the reactants?
a)
left
b)
right
2.
In a chemical equation, on what side of the arrow are the products?
a)
left
b)
right
3.
True or False? During a chemical reaction a new substance (or substances) is produced.
a)
true
b)
false
4.
Count the total number of atoms in the chemical formula:
5H2O2
5H2O2
a)
5
b)
8
c)
12
d)
20
5.
Identify the total number of molecules in the chemical formula:
6CH4
6CH4
a)
6
b)
10
c)
24
d)
30
6.
Which of the following can be changed to balance a chemical equation?
a)
products
b)
element symbols
c)
coefficients
d)
subscripts
7.
A chemical equation is balanced when the number of each type of __________ is the same on both sides of the yield sign.
a)
compound
b)
molecule
c)
formula
d)
atom
8.
Which of the following equations is balanced?
a)
2H2 + O2 ---> H2O
b)
H2 + 2O2 ---> 2H2O
c)
H2 + O2 ---> H2O
d)
2H2 + O2 ---> 2H2O
9.
What does the arrow in a chemical equation mean?
a)
matches
b)
yields
c)
equals
d)
mixes
10.
Which of the following describes the law of conservation of mass?
a)
Reactants + Products = 100%
b)
Matter (mass) cannot be created or destroyed in ordinary chemical and physical changes, but it can change form
c)
Mass of products does not equal mass of reactants
d)
Matter (mass) can be created or destroyed in certain chemical reactions.
11.
Determine the number of oxygen atoms in the following chemical formula:
Pb(NO3)2
Pb(NO3)2
a)
1
b)
6
c)
3
d)
5
12.
Which coefficient will balance the following equation?
Zn + ___ HCl --> ZnCl2 + H2
Zn + ___ HCl --> ZnCl2 + H2
a)
2
b)
6
c)
4
d)
3
13.
How many atoms of hydrogen are in the following chemical formula?
3Mg(OH)2
3Mg(OH)2
a)
5
b)
1
c)
6
d)
2
14.
Which of the following is not a sign of a chemical change?
a)
new color
b)
new odor
c)
new shape
d)
new substance
15.
Carbon monoxide is different from carbon dioxide in that
a)
carbon monoxide has one more oxygen atom
b)
carbon monoxide has one less oxygen atom
c)
carbon monoxide has one more carbon atom
d)
carbon monoxide has one less carbon atom
16.
Which coefficient will balance the following equation?
____ Ca + N2 → Ca3N2
____ Ca + N2 → Ca3N2
a)
6
b)
3
c)
1
d)
2
17.
What is a coefficient?
a)
The large number to the left of a chemical formula.
b)
The small number on the right of the chemical symbol.
c)
The small number on the left of a chemical symbol
d)
The large number at the end of a chemical formula
18.
Which chemical equation is balanced?
a)
Li + F2 → 3LiF
b)
2Li + F2 → LiF
c)
2Li + F2 → 2LiF
d)
2Li + F2 → 3LiF
19.
What is the total number of atoms present in 5Na3PO4?
a)
5
b)
40
c)
55
d)
60
20.
How many atoms of aluminum are on each side of the yield sign in the following equation?
4Al + 3O2 --> 2Al2O3
4Al + 3O2 --> 2Al2O3
a)
2
b)
6
c)
1
d)
4
21.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
Fe + S --> FeS
a)
balanced
b)
unbalanced
22.
True or False? When balancing chemical equations the subscripts can change.
a)
True
b)
False
23.
Which of the following is the correct balanced equation for the unbalanced equation shown?
____ H2 + ____ Cl2 --> ____ HCl
____ H2 + ____ Cl2 --> ____ HCl
a)
2H2 + Cl2 --> 4HCl
b)
H2 + Cl2 --> 2HCl
c)
3H2 + 3Cl2 --> HCl
d)
3H2 + Cl2 --> 3HCl
24.
What is the part of the chemical equation in green called?
Fe + S --> FeS
Fe + S --> FeS
a)
products
b)
yield
c)
reactants
d)
chemical formula
25.
What is the part of the chemical equation in green called?
H2 + O --> H2O
H2 + O --> H2O
a)
reactants
b)
chemical equation
c)
yields
d)
products
26.
What is the little number after an element symbol in a chemical equation called?
Example: H2
Example: H2
a)
subscript
b)
coefficient
c)
atom
d)
equation
27.
True or False? Chemical equations summarize a reaction.
a)
True
b)
False
28.
When you add a coefficient to a molecule, what does it multiply?
a)
Only the element it is directly in front of in the molecule
b)
All of the elements in the molecule
29.
Balance this equation:
Al2O3 -> Al + O2
Al2O3 -> Al + O2
a)
2Al2O3 -> 2Al + 3O2
b)
2Al2O3 -> 4Al + 3O2
c)
3Al2O3 -> 2Al + O2
d)
2Al2O3 -> 3Al + 2O2
30.
Predict the product (without changing coefficients):
BeO + CO2 --> ?
BeO + CO2 --> ?
a)
BeCO3
b)
2BeCO3
c)
Be2CO3
d)
BeOCO2
31.
Predict the products (without changing coefficients):
Ca + 2HCl --> ?
Ca + 2HCl --> ?
a)
4CaCl3 + H2
b)
CaH2 + Cl
c)
CaCl2 + H2
d)
CaCl + H2
32.
Which is the correct formula for:
three hydrogen (H)
one sulfur (S)
four oxygen (O)
three hydrogen (H)
one sulfur (S)
four oxygen (O)
a)
H3SO4
b)
HSO4
c)
H4S3O
d)
H2O
33.
Which of the following is a compound?
a)
Co
b)
O2
c)
C
d)
CO2
34.
Element or compound?
O2
O2
a)
Element
b)
Compound
35.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
24
36.
5CO2
How many molecules are there? How many elements?
How many molecules are there? How many elements?
a)
5 molecules, 2 elements
b)
5 elements, 2 molecules
c)
10 atoms, 5 elements
d)
15 elements, 2 molecules
37.
What does a chemical equation show?
a)
how reactants change into products
b)
how products change into reactants
c)
the loss of matter when elements change
d)
the gain of matter when elements change
38.
Balanced or unbalanced?
C + O2 --> CO2
C + O2 --> CO2
a)
Balanced
b)
Unbalanced
39.
Balanced or unbalanced?
2H2 + O2 --> 2H2O2
2H2 + O2 --> 2H2O2
a)
Unbalanced
b)
Balanced
40.
Balanced or unbalanced?
C2H4 + H2 --> C2H6
C2H4 + H2 --> C2H6
a)
Balanced
b)
Unbalanced
41.
How many atoms are there in total?
H2SO4
H2SO4
a)
6
b)
5
c)
7
d)
3
42.
What coefficient should be used to make the following equation balanced?
N2 + O2 --> ___ NO
N2 + O2 --> ___ NO
a)
1
b)
2
c)
3
d)
4
43.
How many water (H2O) molecules are produced?
a)
2
b)
6
c)
8
d)
1
44.
How many oxygen (O2) molecules are produced?
a)
2
b)
4
c)
8
d)
1
45.
Is this equation balanced?
a)
yes
b)
no
46.
Is this equation balanced?
a)
yes
b)
no
47.
Is this equation balanced?
a)
yes
b)
no
48.
Is this equation balanced?
a)
yes
b)
no
49.
Is this equation balanced?
HgO + Cl2 --> HgCl + O2
HgO + Cl2 --> HgCl + O2
a)
yes
b)
no
50.
Identify the correct coefficients to balance this equation:
___ Zn + ___ O2 --> ___ ZnO
___ Zn + ___ O2 --> ___ ZnO
a)
2, 1, 2
b)
1, 2, 1
c)
4, 2, 4
d)
2, 2, 1
51.
Identify the correct coefficients to balance this equation:
___ N2 + ___ H2 --> ___ NH3
___ N2 + ___ H2 --> ___ NH3
a)
2, 3, 2
b)
1, 3, 1
c)
1, 3, 2
d)
1, 2, 3
52.
Identify the correct coefficients to balance this equation:
_____ B + _____ F2 --> _____ BF3
_____ B + _____ F2 --> _____ BF3
a)
1, 2, 3
b)
2, 3, 2
c)
3, 1, 2
d)
2, 2, 3
53.
Identify the correct coefficients to balance this equation:
____ H2 + ____ O2 --> ____ H2O
____ H2 + ____ O2 --> ____ H2O
a)
2, 1, 2
b)
2, 2, 3
c)
4, 1, 2
d)
2, 2, 1
54.
Identify the correct coefficients to balance this equation:
_ Fe + _ H2O -> _ Fe3O4 + _ H2
_ Fe + _ H2O -> _ Fe3O4 + _ H2
a)
3, 2, 1, 4
b)
3, 4, 1, 2
c)
3, 2, 4, 1
d)
3, 4, 1, 4
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