AnswersLA-Chemistry AElements, Compounds, and Mixtures

Elements, Compounds, and Mixtures Answers

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A solid precipitate is formed from the reaction of lead nitrate and sodium chromate. What would be the best method to separate this solid from the solution?

A
distillation
B
evaporation
C
filtration
D
sorting
2
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Which cannot be chemically broken down into simpler substances?

A
compound
B
element
C
solution
D
mixture
3

Which is a pure substance?

A
soda
B
gasoline
C
salt water
D
carbon dioxide
4

Which best describes a compound such as sodium chloride?

A
a pure substance that can be separated into different elements by physical means
B
a mixture of two common substances that can be separated by chemical means
C
a mixture of two common elements that can be separated by physical means
D
a pure substance that can be separated into different elements by chemical means
5

Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of –7.2°C. Bromine can be classified as a

A
compound.
B
impure substance.
C
mixture.
D
pure substance.
6

Which sample is a pure substance?

A
zinc oxide
B
sugar dissolved in water
C
pond water
D
soil
7

A teacher makes the following statement.“Gasoline boils at a relatively low temperature (about 150°C). The kerosene is removed at around 200°C, followed by diesel oil at 300°C and fuel oil at around 370°C.”What topic is the teacher most likely talking about?

A
distillation of a mixture
B
filtration of a pure substance
C
evaporation of a mixture
D
sorting of a pure substance
8

Which is a substance that is made up of only one type of atom?

A
compound
B
element
C
solution
D
mixture
9

The table shows the percentages of hydrocarbons that are found in a sample of crude oil.HydrocarbonsPercentageparaffins30naphthenes49aromatics15asphaltics6.0Based on the given information, what is the best classification for this sample of crude oil?

A
an element
B
a pure compound
C
a pure substance
D
a mixture
10

A chemist is studying an unknown substance and could break the substance into its elemental components only by using chemical means. Based on this observation, how should the unknown substance be classified?

A
impure substance
B
solution
C
mixture
D
pure substance

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