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WorksheetsChemical Reactions by Schott
Total questions: 41
Worksheet time: 38mins
Name
Class
Date
1.
In the equation,
2Mg + O2 ---> 2MgO, which are the reactants?
2Mg + O2 ---> 2MgO, which are the reactants?
a)
Mg and O
b)
MgO
c)
Mg and MgO
d)
O and MgO
2.
Exothermic reactions...
a)
Absorb energy
b)
Release energy
c)
Release Color
d)
Absorb Color
3.
What type of chemical reaction is this one?
Al(OH)3 --> Al2O3 + H2O
Al(OH)3 --> Al2O3 + H2O
a)
Decomposition
b)
Combustion
c)
Synthesis
d)
Single Replacement
4.
What type of chemical reaction is this one?
CUO + CO2 --> CuCO3
CUO + CO2 --> CuCO3
a)
Decomposition
b)
Combustion
c)
Synthesis
d)
Single Replacement
5.
What is a coefficient?
a)
The small number on the right of the chemical symbol.
b)
The large number to the left of a formula.
6.
What is a product?
a)
What's left of the chemical reaction.
b)
The beginning formulas.
7.
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)
Based on the Law of Conservation of Matter, matter cannot be created or destroyed.
d)
Based on the Law of Conservation of Energy, energy cannot be created or destroyed.e
8.
What must go in the blank space to balance the equation?
4Fe + _O2 --> 2Fe2O3
4Fe + _O2 --> 2Fe2O3
a)
1
b)
2
c)
3
d)
4
9.
A reaction that gives off heat to its surroundings is...
a)
exothermic
b)
endothermic
c)
endergonic
d)
none of these
10.
The right side of the equation below is called the
a)
products
b)
reactants
11.
The left side of the equation below is called
a)
Products
b)
Reactants
12.
A chemical change is different than a physical change because in a chemical change
a)
Chemicals are used
b)
Molecules do not physically touch
c)
A new substance is formed and in a physical change no new substance is formed
d)
The change can be seen but in a physical change it cannot
13.
Which statement explains the Law of Conservation of Matter?
a)
In a chemical
reaction, matter can only be destroyed.
b)
In a
chemical reaction, matter can only be created.
c)
Matter can neither be
created nor destroyed in a chemical reaction.
d)
Matter can be created
or destroyed in a chemical reaction.
14.
The substances to the right of the arrow in a chemical equation are called-
a)
coefficient
b)
reactant
c)
subscript
d)
product
15.
How many atoms of hydrogen (H), sulfur (S), and oxygen (O) are there in sulfuric acid (H2SO4)?
a)
H-6, S-4, O-4
b)
H-1, S-2, O-8
c)
H-2, S-1, O-4
d)
H-2, S-4, O-4
16.
2Ca + O2 --> 2CaO What is the 2 located in front of calcium (Ca) called?
a)
coefficient
b)
subscript
c)
reactant
d)
product
17.
You know you a chemical reaction has occurred if
a)
there is a precipitate.
b)
there is a color change.
c)
there is a temperature change.
d)
All of these answers are evidence.
18.
Jane shook, then opened a bottle of soda, and it fizzed over. Is this evidence of a chemical reaction?
a)
yes
b)
no
19.
What kind of reaction is shown in the picture
a)
Endothermic
b)
Exothermic
c)
Explosive
d)
Boring
20.
The energy needed to start a chemical reaction is the _____________________.
a)
Activation Energy
b)
Products
c)
Reactants
d)
Enzymes
21.
_______________ can speed up the rate of reactions and/or lower the amount of energy needed for the reaction to take place.
a)
Carbohydrates
b)
Fuel source
c)
Chemical
d)
Catalyst
22.
Enzymes work by lowering the __________________ for chemical reactions.
a)
Products
b)
Solutes
c)
Activation Energy
d)
Reactants
23.
Chemical reactions that release energy are known as ________________________.
a)
Endothermic
b)
Exothermic
c)
Boring
d)
Reactions
24.
Chemical reactions that absorb energy are known as ________________________.
a)
Endothermic
b)
Exothermic
c)
Boring
d)
Explosive
25.
Is burning wood a chemical or physical change?
a)
chemical
b)
physical
26.
When you observe a physical property, the substance __________.
a)
Changes
b)
Doesn't Change
c)
Burns
d)
Melts
27.
A nail rusts
a)
Physical Property
b)
Chemical Property
28.
This is used to represent the number of each atom being represented.
a)
A Exponent
b)
The Coefficient
c)
A Molecule
d)
The Subscript
29.
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
30.
How many oxygen atoms are in this chemical formula?
a)
6 oxygen atoms
b)
2 oxygen atoms
c)
3 oxygen atoms
d)
4 oxygen atoms
31.
Is this balanced?
2HgO → 2Hg + O2
2HgO → 2Hg + O2
a)
Yes
b)
No
32.
Is this balanced?
Al + O2 → 2Al2O3
Al + O2 → 2Al2O3
a)
Yes
b)
No
33.
To balance a chemical equation, you should change ONLY the...
a)
subscripts
b)
coefficients
c)
chemical formulas
d)
direction of the arrow
34.
A + B --> AB What type of chemical reaction is this?
a)
single
b)
double
c)
synthesis
d)
decomposition
35.
Which of the below is not evidence of a chemical reaction?
a)
Color Change
b)
Temperature Change
c)
Gas Production
d)
Changing Physical Form
36.
Chemistry is....
a)
A characteristic of that can be observed without changing the substance
b)
The study of matter and how matter changes
c)
Anything that has mass and takes up space
d)
A rapid reaction between oxygen and a substance
37.
What is a yield?
a)
The arrow in an equation that represents the chemical reaction.
b)
The beginning substances.
38.
Is melting an object technically known as a chemical reaction?
a)
I don't know
b)
Yes
c)
No
39.
Which is a Synthesis Reaction?
a)
A + B ----> AB
b)
AB -----> A + B
40.
Which is NOT an example of chemical change?
a)
production of gas.
b)
change in color.
c)
change in size.
d)
transfer of energy.
41.
Which is a Decomposition Reaction?
a)
AB --> A + B
b)
ab ----> a + B
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