Worksheets8th Grade Chemistry Unit Test Review
Total questions: 44
Worksheet time: 22mins
Name
Class
Date
1.
What phase change occurs when water droplets form on a cold window from a student's breath?
a)
Freezing
b)
Condensation
c)
Boiling
d)
Evaporation
2.
How do the properties of sodium chloride (NaCl) compare to those of sodium and chlorine?
a)
The same as those of sodium but not chlorine
b)
The same as those of chlorine but not sodium
c)
The same as both sodium and chlorine
d)
Different from those of sodium and chlorine
3.
What best describes the combination of iron filings and sand?
a)
Solution
b)
Compound
c)
Heterogeneous Mixture
d)
Homogeneous Mixture
4.
Which method would effectively separate iron filings from sand?
a)
Pour water into the mixture
b)
Use a magnifying glass
c)
Use a magnet
d)
Heat the mixture
5.
Why is breaking a window considered a physical change?
a)
Energy is required to break the glass
b)
No new substances are created
c)
The mass of the glass is increased
d)
Sound energy is released
6.
What does the recovery of sugar from a solution by evaporation demonstrate?
a)
Phase Change
b)
Physical Change
c)
Chemical Property
d)
Chemical Change
7.
To dissolve more NH ₃ in a solution, what should you do?
a)
Heat the solution
b)
Cool the solution
c)
Keep the solution’s temperature the same
8.
How many grams of KNO₃ will dissolve in 100 mL of water at 60°C? (Use the graph we colored)
a)
30g
b)
60g
c)
90g
d)
102g
9.
What temperature is needed to dissolve 50 g of NH₃ ? (Use the graph we colored)
a)
22°C
b)
36°C
c)
40°C
d)
50°C
10.
In which condition will sugar dissolve the fastest? (Powdered means we crushed up the sugar cube)
a)
Powder and cold water
b)
Powder and hot water
c)
Cube form and cold water
d)
Cube form and hot water
11.
What must happen for a substance to change from liquid to solid?
a)
Lose heat energy and slow down
b)
Gain heat energy and speed up
c)
Lose cold energy and speed up
12.
What does burning paper and leaving black ashes demonstrate?
a)
Physical change in which no new substance is formed
b)
Phase change with heat energy being released
c)
Chemical change in which a new substance is formed
13.
Why can sand and sugar be separated using water?
a)
Sugar would float and sand would sink
b)
Sugar is magnetic and sand is not
c)
Sugar is soluble in water, sand is not
d)
None of the above
14.
In which phase do particles move the fastest and are the farthest apart?
a)
Solid
b)
Liquid
c)
Gas
15.
What are physical properties?
a)
Can be observed only by changing the substance’s identity
b)
Describe how a substance changes into a new substance
c)
Can be observed without changing the substance’s identity
16.
What element supports the burning of a piece of paper?
a)
Hydrogen
b)
Helium
c)
Carbon dioxide
d)
Oxygen
17.
What is the process of separating two liquids by their boiling points called?
a)
Distillation
b)
Sieving
c)
Decanting
d)
Centrifuge
18.
What method is used to separate gravel from water by pouring?
a)
Distillation
b)
Sieving
c)
Decanting
d)
Centrifuge
19.
How is a solution best described?
a)
Element
b)
Compound
c)
Heterogeneous mixture
d)
Homogeneous mixture
20.
How is dihydrogen monoxide or H₂O best characterized?
a)
Element
b)
Compound
c)
Heterogeneous mixture
d)
Homogeneous mixture
21.
What phase change occurs when water droplets appear on a cold window after breathing on it?
a)
Freezing
b)
Condensation
c)
Boiling
d)
Evaporation
22.
What type of change occurs when sugar dissolves in water?
a)
Phase Change
b)
Physical Change
c)
Chemical Property
d)
Chemical Change
23.
Based on the solubility curve, what would you do to dissolve more NH₃?
a)
Heat the solution
b)
Cool the solution
c)
Keep the solution's temperature the same
24.
In which scenario would sugar dissolve the fastest?
a)
Powder in cold water
b)
Powder in hot water
c)
Cube form in cold water
d)
Cube form in hot water
25.
What happens to atoms or molecules during the phase change from liquid to solid?
a)
Lose heat energy and slow down
b)
Gain heat energy and speed up
c)
Lose cold energy and speed up
26.
Why is burning paper considered a chemical change?
a)
No new substance is formed
b)
Heat energy is released
c)
A new substance (ashes) is formed
27.
How could a mixture of sand and sugar be easily separated?
a)
Sugar would float and sand would sink
b)
Sugar is magnetic and sand is not
c)
Sugar is soluble in water and sand is not
d)
None of the above
28.
In which phase of matter do particles move the fastest and are farthest apart?
a)
Solid
b)
Liquid
c)
Gas
29.
What type of properties are color, texture, hardness, and phase at room temperature?
a)
Physical
b)
Chemical
c)
Specific
30.
What element supports the burning of paper?
a)
Hydrogen
b)
Helium
c)
Carbon dioxide
d)
Oxygen
31.
What process separates two liquids based on their boiling temperatures?
a)
Distillation
b)
Sieving
c)
Decanting
d)
Centrifuge
32.
What method of separation is used when water is poured out of a beaker, leaving gravel behind caught by a screen?
a)
Distillation
b)
Sieving
c)
Decanting
d)
Centrifuge
33.
What best describes a solution?
a)
Element
b)
Compound
c)
Heterogeneous mixture
d)
Homogeneous mixture
34.
In a cup of coffee with dissolved sugar, what is the solvent and what is the solute?
a)
Sugar is the solvent, water is the solute
b)
Sugar is the solute, water is the solvent
35.
What happens to liquid molecules when they lose heat energy?
a)
Slow down and move closer together
b)
Speed up and move closer together
c)
Slow down and move farther apart
d)
Speed up and move farther apart
36.
Which of the following best explains why a substance changes from a solid to a liquid?
a)
The molecules lose energy and move closer together.
b)
The molecules gain energy and move farther apart.
c)
The molecules lose energy and move farther apart.
d)
The molecules gain energy and move closer together.
37.
What is the primary reason that a chemical change is different from a physical change?
a)
Chemical changes involve a change in state.
b)
Chemical changes create new substances.
c)
Chemical changes are reversible.
d)
Chemical changes do not involve energy.
38.
Why does increasing the temperature of a solvent generally increase the solubility of a solute?
a)
It decreases the kinetic energy of the molecules.
b)
It increases the kinetic energy of the molecules.
c)
It decreases the surface area of the solute.
d)
It increases the surface area of the solute.
39.
Which of the following scenarios is an example of a chemical change?
a)
Ice melting into water.
b)
Salt dissolving in water.
c)
Iron rusting over time.
d)
Sugar mixing with tea.
40.
What is the main factor that determines the state of matter of a substance at a given temperature and pressure?
a)
The color of the substance.
b)
The mass of the substance.
c)
The arrangement and movement of its particles.
d)
The volume of the substance.
41.
A student mixes salt and water, then boils off all the water. The salt remains. What does this experiment demonstrate about the nature of solutions?
a)
Solutions are always permanent
b)
Solutes and solvents form new compounds
c)
The components of a solution can be separated
d)
Heat always destroys solutions
42.
In a phase change experiment, the temperature of a substance remains constant while heat is being added. What conclusion can be drawn from this observation?
a)
The substance is changing phase
b)
The substance is chemically reacting
c)
The heat is being lost to the environment
d)
The thermometer is faulty
43.
When ice cream melts, it becomes a liquid. However, when you refreeze it, the texture changes. What does this suggest about the relationship between structure and properties in matter?
a)
Chemical changes are always reversible
b)
Physical changes are always reversible
c)
Some physical changes can alter internal structure
d)
Temperature has no effect on molecular arrangement
44.
A student notices that a cold soda can develops water droplets on its outside when left in a warm room. Which process best explains this observation?
a)
Evaporation of the soda
b)
Condensation of water vapor from the air
c)
Sublimation of ice inside the can
d)
Chemical reaction between the can and air
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