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Chemistry Unit 3 Review

Total questions: 45

Worksheet time: 1hrs 6mins

Name
Class
Date
1.

What are the five main types of chemical reactions? Provide an example for each.

a)

Addition, subtraction, multiplication, division, and exponentiation

b)

Solid, liquid, gas, plasma, and Bose-Einstein condensate

c)

Synthesis, decomposition, single displacement, double displacement, and combustion

d)

Acidic, basic, neutral, alkaline, and acidic

2.

Explain the difference between a synthesis reaction and a decomposition reaction.

a)

Synthesis reaction releases energy, while decomposition reaction absorbs energy.

b)

Synthesis reaction only involves one substance, while decomposition reaction involves multiple substances.

c)

Synthesis reaction combines substances, while decomposition reaction breaks them down.

d)

Synthesis reaction breaks substances down, while decomposition reaction combines them.

3.

What are the factors that can affect the rate of a chemical reaction? Provide examples for each factor.

a)

Color, pressure, volume, inhibitor

b)

Time, velocity, weight, reagent

c)

Temperature, concentration, surface area, catalyst

d)

pH, mass, density, solvent

4.

How does temperature affect the rate of a chemical reaction according to the collision theory?

a)

Decrease in temperature leads to an increase in the rate of a chemical reaction.

b)

Increase in temperature leads to an increase in the rate of a chemical reaction.

c)

Temperature has no effect on the rate of a chemical reaction according to the collision theory.

d)

Increase in temperature leads to a decrease in the rate of a chemical reaction.

5.

Explain the concept of activation energy in relation to collision theory.

a)

Activation energy is the maximum amount of energy required for a chemical reaction to occur.

b)

Activation energy is the energy released during a chemical reaction.

c)

Activation energy is the minimum amount of energy required for a chemical reaction to occur.

d)

Activation energy has no relation to collision theory.

6.

What is Le Chatelier's principle and how does it apply to chemical equilibrium?

a)

Le Chatelier's principle explains how a system at equilibrium responds to changes in conditions such as temperature, pressure, or concentration.

b)

Le Chatelier's principle only applies to solid-state reactions

c)

Le Chatelier's principle has no application in chemical equilibrium

d)

Le Chatelier's principle is used to predict the color of a chemical reaction

7.

How does an increase in pressure affect a system at equilibrium according to Le Chatelier's principle?

a)

The system will not shift at all.

b)

The system will shift towards the side with fewer moles of gas.

c)

The system will completely stop all reactions.

d)

The system will shift towards the side with more moles of gas.

8.

State the law of conservation of mass and provide an example to illustrate it.

a)

When wood burns, the mass of the ash, smoke, and gases produced is less than the mass of the original wood

b)

Mass can be destroyed in a chemical reaction

c)

Mass can neither be created nor destroyed in a chemical reaction. For example, when wood burns, the mass of the ash, smoke, and gases produced is equal to the mass of the original wood.

d)

Mass can be created in a chemical reaction

9.

Explain how the law of conservation of mass is applied in balancing chemical equations.

a)

Balancing chemical equations does not involve the law of conservation of mass

b)

The law of conservation of mass is applied in balancing chemical equations by ensuring that the total mass of the reactants equals the total mass of the products.

c)

The law of conservation of mass is not applied in balancing chemical equations

d)

The total mass of the reactants does not need to equal the total mass of the products in balancing chemical equations

10.

What happens to the total mass of the reactants and products in a chemical reaction according to the law of conservation of mass?

a)

The total mass decreases

b)

The total mass becomes zero

c)

The total mass increases

d)

The total mass remains constant

11.
What coefficient should be used to make the following equation balanced?
N2+O2--> _NO 
a)
1
b)
2
c)
3
d)
4
12.

Which equation is balanced?

a)

PbO2 + 2H2

b)

SO2 + H20 --> H2SO4

c)

2Na + 2H2O --> 2NaOH + H2

13.

What law governs the balancing of chemical equations?

a)

Law of Energy

b)

Law of Conservation of Matter/Mass

c)

Law of Gravity

d)

Law of Matter Movement

14.

Balance this equation

_Al +_HCl --> _H2 +_AlCl3

a)

2,6,3,2

b)

it's already balanced

c)

4,12,3,4

d)

2,1,4,5

15.

What are the coefficients that would properly balance this equation?

__H2 + __S --> __H2S

a)

1,1 --> 1

b)

2,2 --> 2

c)

1,2 --> 1

d)

1,2 --> 2

16.

Compare the two pathway diagrams for the same reaction. Which pathway shows the reaction that has taken place with the help of a catalyst?

a)

Pathway 1

b)

Pathway 2

c)

You cannot tell from these graphs.

d)

Both reactions involved an enzyme.

17.

Judging by the energy diagram above, is this reaction exothermic or endothermic?

a)

Exothermic

b)

Endothermic

c)

There is not enough information to tell.

d)

There is not change in the amount of energy in the system.

18.
What letter represents the energy of the products?
a)
A
b)
B
c)
C
d)
D
19.
What letter represents the activation energy?
a)
A
b)
B
c)
C
d)
D
20.

What is the ΔH of this reaction?

a)

40 kJ

b)

20 kJ

c)

80 kJ

d)

-60 kJ

21.
What letter represents ΔH?
a)
A
b)
B
c)
C
d)
D
22.

At what time did the reaction reach equilibrium?

a)

t1

b)

t2

c)

t3

d)

t4

23.

2SO2(g)+O2(g) ⇌ 2SO3(g) + Heat


Adding SO2(g) will

a)

shift equilibrium right

b)

shift equilibrium left

c)

increase rate of reaction

d)

have no change

24.

2SO2(g)+O2(g) ⇌ 2SO3(g) + Heat


Increasing the temperature will...

a)

shift equilibrium right

b)

shift equilibrium left

c)

increase pressure

d)

have no change

25.

2SO2(g) + O2(g) ⇌ 2SO3(g) + Heat


Removing O2(g) will

a)

shift equilibrium right

b)

shift equilibrium left

c)

increase pressure

d)

have no change

26.
2SO2(g)+O2(g)⇌2SO3(g)
Increasing volume of container will
a)
shift equilibrium right
b)
shift equilibrium left
c)
slow rate of reaction
d)
have no change
27.

What is the effect of a catalyst on the rate of a chemical reaction?

a)

A catalyst increases the rate of a chemical reaction by lowering the activation energy.

b)

A catalyst decreases the rate of a chemical reaction by increasing the activation energy.

c)

A catalyst has no effect on the rate of a chemical reaction.

d)

A catalyst increases the rate of a chemical reaction by increasing the activation energy.

28.

What is the correct Lewis structure for BF3?

a)
b)
c)
d)

BF3 (The formula is the Lewis Structure)

29.

MgCl2 + Na ---> NaCl + Mg


What type of reaction is shown by the equation?

a)

Combination/Synthesis

b)

Decomposition

c)

Single Replacement

d)

Double Replacement

30.

What is the correct IUPAC name for the compound P2O5?

*IUPAC stands for International Union of Pure and Applied Chemistry and it is the naming system that we use in class.

a)

phosphorus pentoxide

b)

diphosphorus pentoxide

c)

phosphorus oxide

d)

potassium oxide

31.

Which Lewis Dot Structure  is correct for the particular element?

a)
b)
32.

Which two statements are correct about the figure shown?

a)

It is a covalent bond.

b)

Hydrogen atoms loss electrons and Carbon gains the atoms.

c)

It happens on metal and on another non-metal.

d)

The valence electrons are shared by both atoms.

33.

Fe (s)+CuSO4 (aq) → FeSO4 (aq)+Cu(s)

How do electrons move in this reaction?

a)

Iron loses one electron and sulfate gains one electron

b)

Iron loses two electrons and copper gains two electrons.

c)

Copper loses two electrons, iron and sulfate each gain one electron

d)

Copper gains two electrons, iron and sulfate each lose one electron

34.

Select all of the systems in equilibrium.

a)

two reactant compounds form products at twice the rate as the products decompose

b)

two reactant compounds form products at the same rate as the products decompose

c)

substance in a closed container reaches its melting point

d)

substance in an open container reaches it boiling point

e)

solution becomes saturated

35.

The following equation is incomplete. 2 N2O5 (g) →

Which set of products completes and balances the incomplete equation?

a)

4 NO(g) + SO2 (g)

b)

2 N2(g) + 3 H2(g)

c)

2 N2(g) + 2 O2 (g)

d)

4 NO2 (g) + O2 (g)

36.

The name of FeCl₂ is

a)

iron chloride

b)

iron(II) chloride

c)

iron(I) chloride

d)

iron dichloride

37.

Name for SrBr2

a)

strontium bromine

b)

strontium bromide

c)

strontium dibromide

d)

strontium dibromine

38.
If an atom becomes an ion with a 2+ charge, what does that mean?
a)
It has lost 2 electrons
b)
It has gained 2 electrons
c)
The atom is in period 2
d)
The atom has an atomic # of 2
39.
How do the following two elements bond together?
Cr3+  O2-         
a)
CrO
b)
Cr3O2
c)
Cr2O3
d)
CrO3
40.
How do the following two elements bond together?
Pb4+  O2-       
a)
PbO
b)
Pb4O2
c)
PbO2
d)
Pb2O4
41.

What is the name for S3O8?

a)

Trisulfide octaoxide

b)

Trisulfide oxide

c)

Sulfide octaoxygen

d)

Trisulfur octaoxide

42.
For the equilibrium reaction
2NH3(g) + 22 kJ ↔ N2(g) + 3H2(g),
which of the following changes would result in the formation of more N2 and Hat equilibrium?

a)
increasing pressure
b)
increasing temperature
c)
adding N2
d)
removing NH3
43.
Increasing the temperature of an exothermic reaction will:
a)
shift the reaction to the left towards the reactants, making more of the reactants.
b)
shift the equilibrium to the right towards the products, making more of the product.
c)
Have no effect on equilibrium.
44.

Ammonia is produced commercially by the Haber reaction: N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g) + heat. The formation of ammonia is favored by what?

a)

an increase in pressure

b)

a decrease in pressure

c)

removal of N₂(g)

d)

removal of H₂(g)

45.

What is the correct Lewis Dot Structure for ammonia NH3

a)
b)
c)
d)