WorksheetsChemical reactions
Total questions: 26
Worksheet time: 56mins
Name
Class
Date
1.
True or False
In a chemical reaction, no new atoms are created, and no atoms are destroyed.
In a chemical reaction, no new atoms are created, and no atoms are destroyed.
a)
true
b)
false
2.
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 change no new substance is formed
d)
The change can be seen but in a physical change it cannot
3.
The left side of the equation below is called
a)
Products
b)
Reactants
4.
The right side of the equation below is called the
a)
products
b)
reactants
5.
Which statement is not a description of a chemical reaction?
a)
A solid is dropped into a beaker of liquid and a gas is released.
b)
Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker.
c)
A solid is dropped into a beaker of liquid and an explosion occurs.
d)
A liquid is heated in the sun and half of it evaporates.
6.
A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.
a)
Coefficient
b)
reactant
c)
subscript
d)
product
7.
A chemical reaction that absorbs heat
a)
Single replacement
b)
Exothermic
c)
Endothermic
d)
Decomposition
8.
Which of the following is NOT a sign of a chemical reaction?
a)
Color changes
b)
Cutting into fourths
c)
Light is produced
d)
Gas is formed
9.
In a chemical reaction
a)
The atoms of the reactants always stay together to form the products
b)
The atoms of the reactants unbond, rearrange, and then rebond to form the products
c)
New atoms are formed which combine to make the products
d)
Some atoms disappear while others multiply to form the products
10.
Which of the following answers will balance the equation below?
__K + __Br2 --> __KBr
__K + __Br2 --> __KBr
a)
2, 1, 1
b)
2, 3, 2
c)
2, 1, 2
d)
1, 2, 3
11.
If the reactants on the left side of a chemical equation are C₃H₈ + 5O₂, the products in a balanced equation could be
a)
4CO₂ + 3H₂O
b)
3CO₂ + 4H₂O
c)
2CO₂ + 3H₂O
d)
3CO + 4H₂O
12.
The correct chemical formula for calcium carbonate is ....
a)
CaCO3
b)
Ca2CO3
c)
Na2CO3
d)
CO2
13.
the starting materials in a chemical reaction
a)
Products
b)
Reactants
c)
Starters
d)
Enders
14.
a substance that is formed as the result of a chemical reaction
a)
Product
b)
Reactant
c)
Starters
d)
Enders
15.
tells us the number of atoms of each element in a compound
a)
Coeffecient
b)
Exponent
c)
Chemical Formula
d)
Calculator
16.
a process or reaction in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat
a)
Endothermic Reaction
b)
Exothermic Reaction
c)
Diffusion
d)
Fission
17.
a chemical reaction that releases energy by light or heat
a)
Endothermic Reaction
b)
Exothermic Reaction
c)
Diffusion
d)
Fission
18.
___C3H8 +___O2 --> ___CO2 + ___H2O
a)
1,5,3,4
b)
2,10,6,8
c)
already balanced
d)
1,5,5,4
19.
__Al + __Fe3N2 -->__AlN + __Fe
a)
already balanced
b)
4,2,4,6
c)
2,1,2,3
d)
1,2,1,3
20.
__Na + __Cl2 --> __NaCl
a)
1,1,2
b)
2,1,2
c)
2,1,1
d)
already balanced
21.
__H2O2 --> __H2O + __O2
a)
already balanced
b)
2,1,1
c)
2,2,1
d)
2,1,2
22.
__C6H12O6 + __O2 --> __H2O + __CO2
a)
1,6,6,6
b)
already balanced
c)
1,6,1,6
d)
2,12,12,12
23.
__H2O + __CO2 --> __C7H8 + __O2
a)
4,7,1,9
b)
4,7,1,7
c)
2,3,1,3
d)
already balanced
24.
__NaClO3 --> __NaCl + __O2
a)
2,2,2
b)
2,2,3
c)
3,2,2
d)
1,2,3
25.
__(NH4)3PO4 + __Pb(NO3)4 --> __Pb3(PO4)4 + __NH4NO3
a)
2,1,1,6
b)
1,2,2,3
c)
4,3,1,12
d)
4,2,1,12
26.
__BF3 + __Li2SO3 --> __B2(SO3)3 + __LiF
a)
2,3,1,3
b)
2,3,1,6
c)
4,4,2,12
d)
3,3,1,9
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