AnswersPA-Science 8 Q1Lab: Rate of Chemical Reactions

Lab: Rate of Chemical Reactions — Unit test Answers

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Which statement best describes the diagram below?

Question illustration
A
The pressure is greater at the bottom of the container.
B
The pressure is greater at the top of the container.
C
The temperature is greater at the top of the container.
D
The temperature is greater at the bottom of the container.
2
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What are the products of the combustion of a hydrocarbon?

A
carbon and oxygen
B
carbon dioxide and water
C
carbon and hydrogen
D
carbon dioxide and hydrogen
3

In which reaction would the activation energy result in an endothermic reaction?

A
water freezing
B
an egg cooking
C
a candle burning
D
iron rusting
4

Which clue can be used to identify a chemical reaction as a decomposition reaction?

A
The reaction involves oxygen.
B
The reaction involves ions.
C
The reaction has a single reactant.
D
The reaction has a single product.
5

Which is a characteristic of atoms?

A
They come in ten major types.
B
They are the smallest units of matter.
C
They can be found in nonliving things only.
D
They cannot combine together.
6

Which is the amount of matter in an object?

A
weight
B
mass
C
volume
D
pounds
7

Abi measures the volume and weight of four objects and records his data in this table.Which object has the most mass?

Question illustration
A
W
B
X
C
Y
D
Z
8

Four students made statements about a tennis ball they were using in a lab.Which student made a mistake in her statement?

Question illustration
A
Irma
B
Julia
C
Grace
D
Masha
9

The release of a gas from a chemical reaction is very quick. A scientist wants to measure what is released, but in small increments. What would allow the scientist to change the rate of the reaction so the results could be measured?

A
an enzyme
B
an inhibitor
C
a depressant
D
an accelerator
10

Which type of reaction has the general formula of AB + CD → AD + CB?

A
synthesis
B
decomposition
C
oxidation
D
replacement
11

The activation energy of a reaction going on its own is 20 kJ. If the reaction was treated with a catalyst, which would most likely represent the amount of energy needed to start a reaction?

A
15 kJ
B
20 kJ
C
25 kJ
D
30 kJ
12

What else is produced during the replacement reaction of silver nitrate and potassium sulfate?2AgNO3 + K2SO4 Ag2SO4 + ________

Question illustration
A
KNO3
B
2KNO3
C
K2
D
2AgNO3
13

Which type of reaction is NaCl + AgNO3 → NaNO3 + AgCl?

A
synthesis
B
decomposition
C
oxidation
D
replacement
14

Which clue can be used to identify a chemical reaction as a combustion reaction?

A
Oxygen is a product.
B
A hydrocarbon reacts with oxygen.
C
Water and carbon dioxide react.
D
The reaction involves ions.
15

Why is reaching activation energy necessary?

A
Reactants require a minimum amount of energy to start to break a chemical bond.
B
Products require a minimum amount of energy to start to break a chemical bond.
C
Reactants must have the maximum amount of energy to start to break a chemical bond.
D
Products must have the maximum amount of energy to start to break a chemical bond.
16

Andre is predicting the products of chemical reactions. In one reaction, a hydrocarbon is the only reactant. What is the best prediction and explanation of this reaction?

A
Two new compounds form as the hydrocarbon undergoes a synthesis reaction.
B
Carbon dioxide and water form because the hydrocarbon undergoes a combustion reaction.
C
A polymer forms because the hydrocarbon joins with itself in a polymerization reaction.
D
Oxides form because the hydrocarbon combines with oxygen in an oxidation reaction.
18

Imagine that Kevin can instantly transport himself between Planet X and Planet Y. Which statement could be said about Kevin in this situation?

A
Kevin’s weight may change between Planet X and Planet Y.
B
Kevin’s volume may change between Planet X and Planet Y.
C
Kevin’s mass may change between Planet X and Planet Y.
D
Kevin’s matter may change between Planet X and Planet Y.
19

The typical speed of a reaction releases gas every twenty seconds for two minutes. The chart lists four substances that were added to the reaction at different times. Which statement best summarizes the chart?

Question illustration
A
Substances W and Y are catalysts, and substances X and Z are inhibitors.
B
Substance W is an inhibitor, and substances X, Y, and Z are catalysts.
C
Substances W and Z are inhibitors, and substances X and Y are catalysts.
D
Substance X is a catalyst, and substances W, Y, and Z are inhibitors.
20

Krishne wants to measure the mass and volume of a key. Which tools should she use?

A
a balance and a beaker of water
B
a balance and a meter stick
C
a beaker of water and a ruler
D
a ruler and a meter stick
21

Rosa was looking for patterns to help predict the products of chemical reactions. She recorded three similar decomposition reactions in the table.What products should she record in the last row of the table?

Question illustration
A
2LiCl + 3O2
B
3LiCl + 2O2
C
2LiO + 3Cl2
D
3LiO+ 2Cl2

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