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Chemical reactions 2023-2024

Total questions: 76

Worksheet time: 1hrs 2mins

Name
Class
Date
1.

Which of the following is a reactant in the following equation?


O2 + C6H12O6 > CO2 + H2O

a)

CO2

b)

H2O

c)

O2

2.

Which of the following is a reactant in the following equation?


O2 + C6H12O6 > CO2 + H2O

a)

CO2

b)

H2O

c)

O2

3.

Tiny pieces of matter that everything is made of

a)

model

b)

atoms

c)

substances

4.

An object, diagram, or computer program that helps us understand something by making it simpler or easier to see

a)

molecule

b)

property

c)

model

5.

A process in which atoms rearrange to form new substances.

a)

extended structure

b)

boiling point

c)

chemical reaction

6.

In a chemical equation the reactants are on the left side of the arrow. Are the reactants the beginning substances or the ending substances?

a)

beginning

b)

ending

7.

In a chemical equation the products are on the right side of the arrow. Are the products the beginning substances or the ending substances?

a)

beginning

b)

ending

8.

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

9.

Burning paper is an example of a

a)

boiling point

b)

chemical reaction

c)

extended structure

10.

When a new substance forms as a result of a chemical reaction, what type of change has occurred?

a)

Chemical Change

b)

Physical Change

11.

Which is NOT an indication of a chemical change?

a)

Temperature Change

b)

Shape Change

c)

Formation of a precipitate

d)

Production of light

12.

Explain what is happening in the following image.

4 lines
13.

What is the left part of a chemical equation called?

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

14.

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

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

15.

What is the left part of a chemical equation called?

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

16.

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

2H2 + O2 --> 2H2O

a)

Reactants

b)

Yields

c)

Products

d)

Chemical Equation

17.

True or False

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

a)

TRUE

b)

FALSE

18.

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.

19.

Which chemical equation matches the model shown?

a)

3C + 4O --> 3CO2

b)

3C + 2O2 --> 3CO2

c)

C3 + 4O --> 3CO6

d)

C3 + 2O2 --> 3CO6

20.
What is a molecule?
a)
Two or more atoms bonded together
b)
One element
c)
One atom
d)
Solid, Liquid, Gas
21.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
a)
2
b)
6
c)
1
d)
4
22.
In the equation,          2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
23.
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
24.

6CO2+ 6H2O → C6H12O6 + 6O26CO_2+\ 6H_2O\ \rightarrow\ C_6H_{12}O_{6\ }+\ 6O_2  

The carbon atoms are balanced with ____ on each side of the reaction.

a)

1

b)

6

c)

2

25.

Determined whether the following equation is balanced or unbalanced. Ag + O2 ---> 2Ag2O

a)

Balanced

b)

Unbalanced

26.

Determine whether the following equations is balanced or unbalanced. H4 + O2 ---> 2H2O

a)

Balanced

b)

Unbalanced

27.

Determine whether the following equation is balanced or unbalanced. H2 + Br2 ---> 2HBr

a)

Balanced

b)

Unbalanced

28.

Determine whether the following equation is balanced or unbalanced. 2Fe + 3Cl2 ---> FeCl3

a)

Balanced

b)

Unbalanced

29.

In order for an equation to be balanced, there must be ...

a)

an equal amount of atoms on both sides

b)

a greater mass on the product side

c)

a greater mass on the reactant side

d)

elements with the same atomic # on both sides

30.
The law of conservation of mass states that....
a)
Matter can be made
b)
Matter can be destroyed
c)
Matter can neither be made or destroyed
d)
Matter can evaporate
31.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
a)
balanced
b)
unbalanced
32.
Is this balanced?...
Al + O2 --> 2Al2O3
a)
Yes!
b)
NO!
33.

Determine whether the following equation is balanced or unbalanced. 4P +5O2 ---> 2P2O5

a)

Balanced

b)

Unbalanced

34.
How many atoms of aluminum are on each side of the following equation: 4Al + 3O2 --> 2Al2 O3
a)
2
b)
6
c)
1
d)
4
35.
How many atoms of carbon (C) are in C6H12O6?
a)
3
b)
6
c)
12
d)
24
36.

Check ALL the boxes that show the signs of a chemical change.

a)

smell

b)

air

c)

color change

d)

gas (bubbles) produced

e)

forces

37.
During an endothermic reaction in a beaker if we are part of the surroundings and touched the beaker, it would feel _______. 
a)
Warm
b)
Cold
38.
If a chemical reaction is EXOTHERMIC, the temperature would....
a)
Stay the same
b)
Increase
c)
Decrease
39.

The reactants in the image above are:

a)

CH4 and 2 O2

b)

2 H2O and CO2

c)

All of these are reactants

d)

All of these are products

40.

A substance that is formed as the result of a chemical reaction is a __________________

a)

Product

b)

Reactant

c)

Starters

d)

Enders

41.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
42.
If a chemical reaction is EXOTHERMIC, the temperature would....
a)
Stay the same
b)
Increase
c)
Decrease
43.
During an endothermic reaction in a beaker if we are part of the surroundings and touched the beaker, it would feel _______. 
a)
Warm
b)
Cold
44.
Is TNT exploding a physical or chemical change?
a)
Physical
b)
Chemical
c)
Both physical and chemical
d)
Neither physical nor chemical
45.
_________ is (are) made of more than one atom.
a)
A molecule
b)
Protons
c)
Neutrons
d)
An element
46.
Which is an example of a physical change?
a)
Burning wood
b)
Freezing water
c)
Rust on a car
d)
Cooking food
47.
Which is an example of a chemical change?
a)
Burning wood
b)
Rust on a car
c)
Cooking food
d)
All of the above
48.
If you start a chemical reaction with 5 atoms of helium, how many atoms will you have after?
a)
4 atoms
b)
10 atoms
c)
1 atom
d)
5 atoms
49.
Which of the following are properties of matter?
a)
Magnetism
b)
Color
c)
Odor
d)
All of the above
50.
In a chemical equation, is it true that -
a)
the reactant side and product side can have different numbers of atoms for each element
b)
there can be different elements on the reactant side and the product side
c)
an element or compound must be accompanied by a phase change
d)
the coefficients indicate the number of molecules of each reactant used and the number of molecules of each product made
51.
Which of the following models best demonstrates a balanced chemical equation?
a)
F
b)
G
c)
H
d)
J
52.

How many atoms in all are in a molecule of serotonin?

C10H12N2O

a)
22
b)
24
c)
25
d)
4
53.
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
54.
Is burning wood a chemical or physical change?
a)
chemical
b)
physical
55.
Is glass breaking a chemical or phyiscal change?
a)
chemical
b)
physical
56.
Which of the following equations demonstrates an actual chemical reaction that forms a new substance? (HINT: it must follow the Law of Conservation of Mass)
a)
A
b)
B
c)
C
d)
D
57.
Is this balanced?
Al + O2 → 2Al2O3
a)
Yes
b)
No
58.
Which is an example of a chemical reaction?
a)
paper cut into small pieces
b)
chocolate melting in a pan
c)
flour and sugar mixed in a bowl
d)
cookies baking in an oven
59.
Exothermic reactions...
a)
Absorb energy
b)
Release energy
c)
Release Color
d)
Absorb Color
60.
Baking bread and cooking an egg are examples of....?
a)
Endothermic processes
b)
Exothermic processess
c)
None of these 
61.
In an endothermic reaction, heat is ...
a)
taken in or absorbed
b)
given out or released 
62.
Is the following equation balanced or unbalanced?
Fe + S --> FeS
a)
balanced
b)
unbalanced
63.
The thing that does the dissolving
a)
Solute
b)
Solvent
c)
Colloid
d)
Solution
64.
What is a solute?
a)
The substance that does the dissolving in a solution.
b)
The substance that is dissolved into the solution.
c)
The mixing of different substances.
d)
The process in which neutral molecules lose or gain electrons
65.

According to the law of conservation of mass, how does the amount of each element on the product side compare to each element on the reactant side?

a)

The amount of atoms on each side is equal

b)

The amount of atoms on the product side is greater

c)

The amount of atoms on the reactant side is greater

d)

Depends on the reaction

66.
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
67.
In chemical reactions, what does the principle of conservation of mass mean?
a)
Matter is not created or destroyed.
b)
The total mass of the reactants is greater than the total mass of the products.
c)
The total mass of the reactants is less than the total mass of the products.
d)
Matter is not changed.
68.

Tiny pieces of matter that everything is made of

a)

model

b)

atoms

c)

substances

69.

The process by which one or more substances change to produce one or more different substances

a)

Chemical Process

b)

Reactant

c)

Chemical Reaction

70.

A chemical reaction or process that absorbs heat from the surroundings

a)

Endothermic

b)

Exothermic

71.

A chemical reaction or process that releases heat.

a)

Endothermic

b)

Exothermic

72.

Which of the following is NOT a description of an Endothermic reaction

a)

The temperature decreases

b)

Energy is absorbed

c)

Energy is released

d)

Takes more energy to break the bonds than is released

73.

Which option below is an example of an Exothermic reaction

a)

Fireworks

b)

Photosynthesis

c)

Cold pack

d)

Potassium chloride in water

74.

How many atoms of each element on the reactant side of the equation?

a)

4 C, 6 H, 14 O

b)

2 C, 6 H, 2 O

c)

4 C, 12 H, 7 O

d)

4 C, 12 H, 14 O

75.

CH4CH_4  

How many CARBON atoms are in this compound?

a)

1

b)

2

c)

3

d)

4

76.

CH4CH_4  

How many HYDROGEN atoms are in this compound?

a)

1

b)

2

c)

3

d)

4

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