WorksheetsIntro. Chemical Reactions
Total questions: 45
Worksheet time: 1hrs 19mins
Name
Class
Date
1.
indicates substance is a liquid
a)
g
b)
cr
c)
aq
d)
l
2.
The starting substances of a chemical reaction is called
a)
products
b)
substances
c)
reactants
3.
An ending substance that is made during a chemical reaction is called
a)
Reactant
b)
Product
c)
Atom
d)
Molecule
4.
What are Chemical Reactions?
a)
It's when you mix substances.
b)
a process in which atoms rearrange to form new substances
c)
When something bubbles.
d)
letter and numbers showing the types and number of atoms
5.
Describes the number of atoms in a compound of each element.
a)
coefficient
b)
superscript
c)
subscript
d)
SI unit
6.
Which are the products in the reaction shown?
a)
Al2O3
b)
Al
c)
O2
7.
In this image, what are the information in red is called the_______.
a)
Product
b)
Reactant
c)
Chemical Subscript
8.
The symbol for a substance dissolved in water is
a)
(s)
b)
(l)
c)
(g)
d)
(aq)
9.
What is the arrow in a chemical equation...
H2 + O --> H2O
H2 + O --> H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
10.
2 Ca + O2 --> 2 CaO
How many O are there?
a)
2
b)
1
c)
0
11.
2 Ca + O2 --> 2 CaO
Is this reaction balanced?
a)
Yes
b)
No
c)
Maybe
12.
N2 + 3 H2 --> 2 NH3
How many H are there?
a)
2
b)
6
c)
3
13.
___C3H8 +___O2 --> ___CO2 + ___H2O
a)
1,5,3,4
b)
2,10,6,8
c)
already balanced
d)
1,5,5,4
14.
__Na + __Cl2 --> __NaCl
a)
1,1,2
b)
2,1,2
c)
2,1,1
d)
already balanced
15.
__H2O + __CO2 --> __C7H8 + __O2
a)
4,7,1,9
b)
4,7,1,7
c)
2,3,1,3
d)
already balanced
16.
Which is generalized equation represents a decomposition reaction
a)
AB—> A+B
b)
A+B—>AB
c)
A+BC—> AC+B
d)
AB+CD—>AD+CB
17.
Cu + 2Ag(NO₃) —>2Ag + Cu(NO₃)
a)
Double displacement reaction
b)
Decomposition reaction
c)
Synthesis reaction
d)
Single displacement reaction
18.
What type of chemical reaction is this
BaCl₂+MgSO₄→BaSO₄+MgCl₂
a)
Single displacement
b)
Combustion
c)
Synthesis
d)
Double displacement
19.
The number of atoms you begin with in a chemical reaction ...
a)
must be the same as the number of atoms you end with
b)
must be an even number
c)
can be different to the number you finish with
d)
changes depending on how much energy is formed
20.
Balance the following:
____ H2SO4 + ____ NaNO2 → ____ HNO2 + ____ Na2SO4
a)
1,1,2,1
b)
1,2,2,1
c)
2,3,3,2
d)
4,3,2,1
21.
Which type of reaction is:
2 H3AsO4 → As2O5 + 3 H2O
a)
Synthesis
b)
Decomposition
c)
Single Displacement
d)
Combustion
22.
Which type of reaction is:
2 NH3 + H2SO4 → (NH4)2SO4
a)
Synthesis
b)
Decomposition
c)
Single Displacement
d)
Double Displacement
23.
What is the percent by mass of oxygen in MgO?
a)
20%
b)
40%
c)
50%
d)
60%
24.
What is the percent by mass of chlorine in NaCl?
a)
39%
b)
61%
c)
35%
d)
65%
25.
Which of the following is NOT needed to calculate percent composition?
a)
Mass of specific element
b)
Molar Mass
c)
Avogadro's Number
d)
Division
26.
What is the percent composition by mass of sulfur in the compound MgSO4 (gram formula mass = 120 g/mol)?
a)
20%
b)
27%
c)
46%
d)
53%
27.
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.
28.
Is the following equation balanced?...
Al + O2 --> 2Al2O3
Al + O2 --> 2Al2O3
a)
Yes!
b)
No!
29.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
30.
Is the following equation balanced?
2C2H2 + 5O2 --> 4CO2 + 2H2O
2C2H2 + 5O2 --> 4CO2 + 2H2O
a)
yes
b)
no
31.
Is the following equation balanced?
4Fe + 3O2 --> 2Fe2O3
4Fe + 3O2 --> 2Fe2O3
a)
yes
b)
no
32.
Which of the following equations are correctly balanced?
a)
12CO2 +H2O --> C6H12O6 + O2
b)
CO2 + 9H2O --> C6H12O6 + O2
c)
CO2 + H2O --> 3C6H12O6 + O2
d)
6CO2 + 6H2O --> C6H12O6 + 6O2
33.
In which compound is the percent composition by mass of Cl equal to 42%?
a)
HClO (gram formula mass = 52 g/mol)
b)
HClO2 (gram formula mass = 68 g/mol)
c)
HClO3 (gram formula mass = 84 g/mol)
d)
HClO4 (gram formula mass = 100 g/mol)
34.
Find the percent composition of Cu2S?
a)
%Cu= 67.987 %S= 32.013
b)
%Cu= 79.854 %S= 20.145
c)
%Cu= 35.946 %S= 64.054
35.
What is the percent composition of Benzene, C6H6?
a)
C = 50%
H = 50%
H = 50%
b)
C = 85.7 %
H = 14.3%
H = 14.3%
c)
C = 92.2%
H = 7.8%
H = 7.8%
d)
C = 71.9%
H = 28.1%
H = 28.1%
36.
What is the empirical formula for the following:
Pb5Cr5O20
Pb5Cr5O20
a)
Pb2Cr2O10
b)
PbCr2O7
c)
Pb9Cr4O2
d)
PbCrO4
37.
Is the equation balanced?: 2H2O + O2 --> 4MgO + 3Fe
a)
yes
b)
no
38.
The coefficient in 3H2O is
a)
6
b)
5
c)
2
d)
3
39.
How many atoms of carbon (C) are in C6H12O6?
a)
3
b)
6
c)
12
d)
24
40.
How many Sodium (Na) are in 6NaCl?
a)
1
b)
12
c)
6
41.
Balance this equation:
MgCl2 --> Mg4+ Cl2
MgCl2 --> Mg4+ Cl2
a)
It's already balanced.
b)
4MgCl2 --> Mg4+ 4Cl2
c)
4MgCl2 --> Mg4+ 5Cl2
42.
Balance this equation:
2Li + Cl2 -> LiCl
2Li + Cl2 -> LiCl
a)
2Li + Cl2 -> 4LiCl2
b)
2Li + Cl2 -> LiCl2
c)
2Li + Cl2 -> 2LiCl
43.
Name the part in red:
H2 + O2 -> H2O
H2 + O2 -> H2O
a)
Coefficient
b)
Product
c)
Yield
d)
Subscript
44.
How many phosphorus atoms are in PO4?
a)
1
b)
2
c)
3
d)
4
45.
Which number should go in the blank?
_ H2 + O2 -> 2 H2O
_ H2 + O2 -> 2 H2O
a)
1
b)
2
c)
3
d)
0
100 %
