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WorksheetsChemical reactions
Total questions: 20
Worksheet time: 37mins
Name
Class
Date
1.
True or False: In a complete chemical equation, there must be the same number of atoms of each element on the reactants and products side.
a)
True
b)
False
2.
Look at the chemical equation.
Is it written correctly to show the Law of Conservation of Mass?
a)
Yes
b)
No
3.
Look at the chemical equation.
Is it written correctly to show the Law of Conservation of Mass?
a)
Yes
b)
No
4.
Look at the chemical equation.
Is it written correctly to show the Law of Conservation of Mass?
a)
Yes
b)
No
5.
What is the arrow in a chemical equation...
H2 + O --> H2O
H2 + O --> H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
6.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
7.
In the equation, 2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
8.
In a chemical reaction, everything to the right of the arrow is called ______________.
a)
Products
b)
Yields
c)
Molecules
d)
Reactants
9.
Which of the following is evidence of a chemical reaction?
a)
fizzing
b)
water changing to ice
c)
saltwater
d)
paper being cut in half
10.
Which of the following models best demonstrates a balanced chemical equation?
a)
F
b)
G
c)
H
d)
J
11.
Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?
a)
The shape of the coal changes
b)
Oxygen is present
c)
A new substance is produced
d)
Coal is made up of more than one element
12.
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
13.
Which of the following is NOT evidence that that a chemical reaction has occurred?
a)
produces light/heat
b)
production of a gas
c)
formation of a precipitate
d)
melting
14.
A teacher is demonstrating physical and chemical changes to her class. Which action should she use to demonstrate a chemical change?
a)
cutting a piece of paper
b)
folding a piece of paper
c)
tearing a piece of paper
d)
burning a piece of paper
15.
Which of the following describes a precipitate?
a)
a liquid forms when a block of metal is heated
b)
a solid forms when one liquid is poured into another
c)
a gas forms when a solid is placed in a liquid
d)
bubbles form when an acid is poured on a rock
16.
Si + S8 →Si2S4
a)
Synthesis (combination)
b)
Decomposition
c)
Single replacement
d)
Double replacement
17.
Ca + AlCl3→ CaCl2 + Al
a)
Synthesis (combination)
b)
Decomposition
c)
Single replacement
d)
Double replacement
18.
KOH + H3PO4 → K3PO4 + H2O
a)
Synthesis (combination)
b)
Decomposition
c)
Single replacement
d)
Double replacement
19.
Pb(NO3)2 →PbO + NO2 + O2
a)
Synthesis (combination)
b)
Decomposition
c)
Single replacement
d)
Combustion
20.
AB + CD →AD + CB
a)
Double Replacement
b)
Single Replacement
c)
Synthesis
d)
Decomposition
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