WorksheetsChemical Reactions
Total questions: 21
Worksheet time: 19mins
Name
Class
Date
1.
Which of these is NOT a sign that a chemical change has occurred?
a)
A loss of transparency
b)
An unexpected color change
c)
A temperature change
d)
The formation of a precipitate
2.
The Law of Conservation of Mass states
a)
that matter exists in all states and reacts the same
b)
that matter can only be changed into new substances by introducing a catalyst
c)
that matter exists in the same state throughout any chemical change
d)
that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants
3.
How many Al atoms are in this compound? 4Al2O3
a)
2
b)
8
c)
6
d)
4
4.
How many F atoms are in this compound?
6MgF2
6MgF2
a)
2
b)
6
c)
8
d)
12
5.
The number of atoms on one side of a chemical equation is equal to
a)
a molecule of a substance
b)
the amount of gas released during a chemical reaction
c)
the number of atoms on the other side of a chemical equation
d)
all of the matter that exists in the universe
6.
Based on this compound Al₂(SO₄)₃ what can you conclude the charge of sulfate is?
a)
+2
b)
-2
c)
+3
d)
-3
7.
How many hydrogen atoms are in this chemical formula:
a)
4 hydrogen atoms
b)
1 hydrogen atom
c)
2 hydrogen atoms
d)
3 hydrogen atoms
8.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
9.
How many Magnesium are in 10MgCl2?
a)
10
b)
5
c)
20
d)
1
10.
What is the left part of a chemical equation called?
H2 + O → H2O
H2 + O → H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
11.
What is the right part of a chemical equation called?
H2 + O → H2O
H2 + O → H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
12.
One of the signs of a chemical reaction taking place is:
a)
Bubbles are produced in the reacting vessel
b)
Reactants are not combining
c)
Products are not forming
d)
Colour is not changing
13.
Reactions that give out heat to the surrounding are classified as one of the following:
a)
Spontaneous
b)
Sluggish
c)
Exothermic
d)
Endothermic
14.
Why must chemical equations be balanced?
a)
So that the equation doesn't explode
b)
The reaction won't happen until it is balanced
c)
Matter cannot be created or destroyed
d)
None of these
15.
When materials combine to form new compounds it is a chemical change. Which example is a chemical change?
a)
baking powder fizzing
b)
water boiling
c)
ice melting
d)
sugar cube dissolving
16.
This is used to represent the number of each atom being represented.
a)
A Exponent
b)
The Coefficient
c)
A Molecule
d)
The Subscript
17.
A chemical reaction that absorbs heat
a)
Single replacement
b)
Exothermic
c)
Endothermic
d)
Decomposition
18.
A Precipitate forms
a)
when a gas is bubble through a liquid
b)
a lighter taper causes a gas to burn
c)
in a liquid or gas after a reaction and causes cloudiness (caused by a solid forming)
19.
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
20.
A chemical change is?
a)
a shoe lace cut in half
b)
doesn't change anything
c)
changes the look of an object
d)
change that results in the formation of new chemical substances after a reaction occurs
21.
_ tend to react with non-metals.
a)
non-metals
b)
metals
c)
nobel gases
d)
metalloids
100 %
