WorksheetsChemical & Physical Reactions
Total questions: 45
Worksheet time: 1hrs 24mins
Name
Class
Date
1.
which of the following is a sign of a chemical reaction?
a)
Combustion
b)
State change
c)
a solid becoming a gas
d)
a change in texture
2.
which of the following does not always indicate a chemical change?
a)
if a gas is produced
b)
if a new substance is created
c)
if the process cannot be reversed
d)
change in color
3.
which of the following is an example of a physical change?
a)
a candle burning
b)
forming a precipitate
c)
wax melting
d)
mixing baking soda and vinegar
4.
Condensation is an example of what kind of reaction?
a)
physical
b)
chemical
c)
endothermic
d)
it is not a reaction
5.
An exothermic reaction is a reaction that...
a)
absorbs heat
b)
releases heat
c)
feels cold
d)
turns ice into water
6.
An endothermic reaction is a reaction that....
a)
changes color
b)
feels hot
c)
releases heat
d)
absorbs heat
7.
One sign of a chemical change is that a chemical change produces...
a)
a new substance
b)
all of these are correct
c)
a temperature change
d)
a precipitate
8.
As you move up the heat curve the molecules will....
a)
move closer to each other
b)
move further apart from each other
c)
lose energy
d)
release heat
9.
What kind of properties can only be observed when a substance changes into a different substance?
a)
physical properties
b)
chemical properties
c)
liquid properties
d)
real properties
10.
Is hammering wood together to build a house a chemical or physical change?
a)
chemical
b)
physical
11.
Is burning wood a chemical or physical change?
a)
chemical
b)
physical
12.
what is digestion?
a)
body function
b)
chemical change
c)
physical change
13.
A change in the size, shape, or state of matter.
a)
chemical change
b)
physical change
c)
chemical reaction
d)
electron change
14.
All reactions require activation energy.
a)
True
b)
False
15.
Increasing the surface area of the reactants will increase the rate of the reaction.
a)
True
b)
False
16.
Increasing the temperature of a reaction will __________ the rate of the reaction.
a)
increase
b)
decrease
17.
A substance used to decrease the rate of a chemical reaction is called an
a)
enzyme
b)
inhibitor
18.
In an ____________reaction, energy is released.
a)
exothermic
b)
endothermic
19.
In an endothermic reaction, the energy of the products is _________ than the energy of the reactants.
a)
greater
b)
smaller
20.
Chemical formulas and other symbols used to represent a chemical reaction, an easier way to show chemical reactions
a)
products
b)
chemical formula
c)
chemical equation
d)
reactants
21.
The smallest amount of energy needed to start a chemical reaction
a)
activation energy
b)
catalyst
c)
concentration
d)
inhibitor
22.
material that increases the speed of a reaction by lowering the activation energy
a)
activation energy
b)
concentration
c)
catalyst
d)
inhibitor
23.
the amount of substance in a given volume
a)
activation energy
b)
concentration
c)
catalyst
d)
inhibitor
24.
material used to slow down a reaction
a)
activation energy
b)
concentration
c)
catalyst
d)
inhibitor
25.
a very fast reaction between oxygen and a fuel
a)
combustion
b)
fuel
26.
a material that gives off energy when burned
a)
combustion
b)
fuel
27.
Catalysts in the cells of living things are called _______
a)
inhibitors
b)
enzymes
c)
fuel
d)
reactants
28.
The substances you begin a chemical reaction with. They are on the left of the "yield" arrow
a)
reactants
b)
products
29.
The new substances formed as a result of a chemical reaction. They are on the right of the "yield" arrow
a)
reactants
b)
products
30.
The fire triangle includes all of the following factors except _______
a)
heat
b)
fuel
c)
oxygen
d)
carbon dioxide
31.
To control a fire, you must remove one or more parts of the fire triangle
a)
True
b)
False
32.
The three sides to the fire triangle are;
a)
Petrol, Spark, Oxygen
b)
Heat, Fuel, Oxygen
c)
Heat, Paper, Air
d)
Match, Paper, Air
33.
If you throw sand on a fire, you are taking away the fire's ____________.
a)
flames
b)
oxygen
c)
heat
34.
The three elements of the Fire Triangle are heat, oxygen, and _____________.
a)
wood
b)
air
c)
fuel
35.
A change that alters the form or appearance of a substance, but no new chemicals are formed
a)
chemical
b)
physical
36.
A change or reaction that produces one or more new substances. These occur when bonds break and new bonds form
a)
Chemical
b)
Physical
37.
The arrow in a chemical equation is used to represent the word _____
a)
yield
b)
equals
38.
How many O's are in Al₂(SO₄)₃
a)
4
b)
12
c)
7
d)
24
39.
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
40.
Describes the number of atoms in a compound of each element.
a)
coefficient
b)
superscript
c)
subscript
d)
SI unit
41.
An ice pack consists of a chemical reaction that absorbs energy in the form of heat. The reaction is described as
a)
exothermic
b)
endothermic
c)
combustion
d)
electrolyte
42.
The number of atoms in the formula KMnO4 is
a)
2
b)
14
c)
6
d)
12
43.
The number of atoms in the formula 2NaHCO3 is
a)
12
b)
14
c)
7
d)
22
44.
Which of the following is NOT a correct inference that you can make about the burning of gasoline?
a)
New substances are produced
b)
Energy is released
c)
The reaction is a physical change
d)
Chemical bonds are broken and others are formed
45.
The reaction in which wood burns in a fireplace is
a)
exothermic
b)
endothermic
c)
precipitate
d)
an enezyme
100 %
