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Worksheets

Chemical reactions

Total questions: 41

Worksheet time: 21mins

Name
Class
Date
1.

What is the left part of a chemical equation called?

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

2.

What is the right part of a chemical equation called...

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

3.

True or False

In a chemical reaction, no new atoms are created, and no atoms are destroyed.

a)

TRUE

b)

FALSE

4.

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)

A solid is dropped into a beaker of liquid and an explosion occurs.

c)

Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker.

d)

A liquid is heated in the sun and half of it evaporates.

5.

During a chemical reaction, atoms can

a)

be destroyed to form a new substance

b)

be created to form a new substance

c)

be rearranged to form a new substance

6.

Which law states that Matter cannot be created or destroyed?

a)

Law of Conservation of Matter

b)

Law of Gravity

c)

Law of Equivalent Exchange

d)

Law of Matter ad Infinitum

7.
Is this balanced?...
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
8.

How many total atoms are in this compound? Al2O3

a)

2

b)

5

c)

6

d)

3

9.

the starting materials in a chemical reaction are called what?

a)

Products

b)

Reactants

c)

Starters

d)

Enders

10.

a substance that is formed as the result of a chemical reaction is called

a)

Product

b)

Reactant

c)

Starters

d)

Enders

11.

Which chemical equation matches the model shown?

a)

3C + 4O --> 3CO2

b)

3C + 2O2 --> 3CO2

c)

C3 + 4O --> 3CO6

d)

C3 + 2O2 --> 3CO6

12.

What colour is copper(II)carbonate

a)

white

b)

blue

c)

colourless

d)

green

13.

copper(II)carbonate → ___________ + carbon dioxide

a)

copper(I) oxide

b)

copper(II) oxide

c)

copper oxide

d)

copper(III) oxide

14.

What happens when CO2 is bubbled through limewater

a)

It changes from pink to blue

b)

It goes pop

c)

It goes cloudy

d)

It gets hot

15.

What colour is copper (II) oxide

a)

white

b)

green

c)

blue

d)

black

16.

______________ (+ heat) → zinc oxide + carbon dioxide

a)

zinc carbonate

b)

zinc oxide

c)

zinc dioxide

d)

zinc hydrogen carbonate

17.
What is the term for when a large molecule is broken down into smaller molecules?
a)
Reaction  
b)
decomposition 
c)
atom  
d)
melting
18.
1.  What is the symbol for carbon dioxide?
a)
CO2   
b)
CO2  
c)
 CO
d)
CO
19.
1.  An endothermic reaction…
a)
Gives out heat   
b)
Takes in heat 
20.

Metal Carbonate

a)

Metal Oxide + Carbon

b)

Metal Carbonate + Oxygen

c)

Metal Oxide + Carbon Dioxide

d)

Carbon Dioxide + Metal

21.
What is essential for a combustion reaction to begin?
a)
Carbon dioxide
b)
Fuel 
c)
Fuel, oxygen and heat
d)
Water and oxygen
22.

8.7: Combustion is when a __________ reacts with oxygen

a)

petrol

b)

fuel

c)

fire triangle

d)

carbon dioxide

23.
Another term for burning is
a)
Fire triangle
b)
Magnesium oxide
c)
Combustion
d)
Bustion
24.

Which one of the following is not a fossil fuel?

a)

Wood

b)

Coal

c)

Petrol

d)

Natural Gas

25.

Why do we burn a fuel?

a)

To have fun

b)

To release energy

c)

To lose energy

d)

To produce carbon dioxide

26.
Balance this equation:
 2Li + Cl2 -> LiCl
a)
2Li + Cl2 -> 4LiCl2
b)
2Li + Cl2 -> LiCl2
c)
2Li + Cl2 -> 2LiCl
27.
Is the following equation balanced or unbalanced ? 
N2 +3 H2 --> 2NH3
a)
Balanced
b)
Unbalanced
28.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O--> 2AlO3
a)
2
b)
6
c)
1
d)
4
29.

Exothermic reactions are ones that.....

a)

Release energy to the surroundings

b)

Absorb energy from the surroundings

c)

Remain at a constant temperature

d)

Decrease in temperature

30.

An example of an endothermic reaction is......

a)

burning

b)

neutralisation

c)

thermal decomposition

d)

metal and acid reactions

31.
Is photosynthesis an exothermic or endothermic reaction?
a)
Endothermic
b)
Exothermic
c)
Neither
32.

The initial temperature was measured to be 20oC and the final temperature was 10oC. The reaction was

a)

exothermic

b)

endothermic

33.

The initial temperature was measured to be 20oC and the final temperature was 45oC. The reaction was

a)

exothermic

b)

endothermic

34.

Which reaction is endothermic?

a)

acid neutralising alkali causing a temperature increase

b)

adding magnesium to hydrochloric acid

c)

calcium carbonate decomposing when heated

d)

combustion of fossil fuels

35.

Which statements about exothermic and endothermic reactions are correct?

1 During an exothermic reaction, heat is given out.

2.The temperature of an endothermic reaction goes up because heat is taken in.

3.Burning methane in the air is an exothermic reaction.

a)

All

b)

1 and 2 only

c)

1 and 3 only

d)

2 and 3 only

36.

Solutions of two chemicals are mixed. A reaction occurs and the temperature change is measured. Which statement is correct?

a)

If the reaction is endothermic, the temperature decreases and energy is taken in.

b)

If the reaction is endothermic, the temperature increases and energy is given out.

c)

If the reaction is exothermic, the temperature decreases and energy is given out.

d)

If the reaction is exothermic, the temperature increases and energy is taken in.

37.

Some white anhydrous copper(II) sulfate powder is put into a beaker of water and stirred. What would show that the process was exothermic?

a)

A blue solution is formed.

b)

The beaker feels cooler.

c)

The beaker feels warmer.

d)

The powder dissolves in the water.

38.
What should be written between the reactants and products?
a)
an equal sign
b)
a triangle
c)
an arrow
d)
the word "yields"
39.

Which of these fuels are fossil fuels?

a)

colal

b)

oil

c)

natural gas

d)

hydrogen

40.

Which of these fuels are non renewable?

a)

coal

b)

oil

c)

natural gas

d)

hydrogen

41.

what observations are seen when sodium is placed in water

a)

It floats

b)

It moves around the surface of the water

c)

fizzing

d)

melts to a sphere