Worksheets8th Grade Chemistry Review
Total questions: 30
Worksheet time: 12mins
Name
Class
Date
1.
How many atoms of carbon (C) are in C6H12O6?
a)
3
b)
6
c)
12
d)
24
2.
The red numbers in the image below represent ________
a)
subscripts
b)
coefficients
c)
I don't know, and don't want to try
d)
None of the answers are correct
3.
The blue numbers in the image below represent ________
a)
I don't know, and don't want to try
b)
coefficients
c)
subscripts
d)
none of the answers are correct
4.
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.
5.
The substances at the beginning of a chemical equation are called the ____
a)
product
b)
yield
c)
chemical symbol
d)
reactants
6.
What is the left part of a chemical equation called?
2H2 + O2 --> 2H2O
2H2 + O2 --> 2H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
7.
What is the right part of a chemical equation called...
2H2 + O2 --> 2H2O
2H2 + O2 --> 2H2O
a)
Reactants
b)
Products
c)
Yields
d)
Chemical Equation
8.
Is the following equation balanced?...
Al + O2 --> 2Al2O3
Al + O2 --> 2Al2O3
a)
Yes!
b)
No!
9.
Is the following equation balanced?
4Fe + 3O2 --> 2Fe2O3
4Fe + 3O2 --> 2Fe2O3
a)
yes
b)
no
10.
Which of the following models best demonstrates a balanced chemical equation?
a)
F
b)
G
c)
H
d)
J
11.
a copper penny turning greenish after a few years.
a)
Physical change
b)
Chemical change
12.
Which of the following IS a physical change?
a)
Getting a haircut
b)
Rusty metal
c)
sour milk
d)
A compound
13.
Two Reactants and One Product
a)
Decomposition
b)
Synthesis
c)
Combustion
d)
Single Replacement
14.
AB = A + B
a)
Decomposition
b)
Single Replacement
c)
Combustion
d)
Synthesis
15.
How many ATOMS of Oxygen are in 3Fe2O3
a)
2
b)
3
c)
6
d)
9
16.
What is the mass of H2O in the reaction above?
a)
70.01
b)
24.11
c)
21.44
d)
48.22
17.
During an endothermic reaction, what happens to energy in relation to the surroundings?
a)
released to
b)
absorbed from
c)
mixed with
18.
During an exothermic reaction, what happens to energy in relation to the surroundings?
a)
released to
b)
absorbed from
c)
mixed with
19.
In a cold pack, which type of reaction draws heat from the surroundings?
a)
exothermic
b)
endothermic
c)
exergonic
20.
Photosynthesis is a chemical reaction that involves the production of glucose (sugar) from carbon dioxide and water in the presence of sunlight. Photosynthesis is what kind of reaction?
a)
Exothermic
b)
Endothermic
c)
Decomposition
21.
A ______ is a substance that speeds up the rate of a
chemical reaction without being used up in the reaction itself.
a)
Concentration
b)
Catalyst
c)
surface area
22.
Adding ______ will increase the rate of reaction because
this causes the particles of the reactants to move more quickly, resulting in more
collisions and more _________.
a)
Heat / Energy
b)
Higher Concentrations / Explosions
c)
Catalysts / Casualties
d)
Reactants / Products
23.
Grinding a seltzer tablet into powder increases the rate of reaction due to increased
a)
concentration
b)
surface area
c)
temperature
d)
reactants
24.
Which factors increase the rate of a reaction.
a)
increasing temperature
b)
increasing concentration
c)
increasing surface area
d)
all of these
25.
What is rate of reaction?
a)
How fast a reaction is
b)
How big a reaction is
c)
How loud a reaction is
d)
How much gas a reaction produces
26.
Increased surface area ______ reaction rate.
a)
Increases
b)
Decreases
27.
Which reaction is endothermic?
a)
Welding
b)
Using an athletic cold pack
c)
Iron Rusting
d)
Burning Wood
28.
If two substances react and the temperature of the mixture increases, the reaction is
a)
Endothermic
b)
Not one that produces anything new
c)
One that needs a catalyst
d)
Exothermic
29.
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
30.
Which of the following is an example that includes evidence of a chemical reaction?
a)
A sample of zinc is placed in water and it settles to the bottom
b)
A solid block of ice is heated and it completely melts into a liquid.
c)
Sugar that is burned gives off an odor and turns brown and then black.
d)
A tomato is placed into a blender and chopped up into smaller pieces.
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