Chemical Properties Answers

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1
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Which characteristic of a substance is considered a chemical property?

A
its boiling point
B
its reactivity
C
its density
D
its conductivity
2
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In a science demonstration, a teacher mixed zinc (Zn) with hydrogen chloride (HCl) in a flask and quickly attached a balloon over the mouth of the flask. Bubbles formed in the solution and the balloon inflated.

A
The Zn and HCl both retained their identity.
B
Either Zn or HCl, but not both, retained its identity.
C
Evaporation of one of the substances occurred.
D
One or more new substances formed.
4

Which laboratory activity involves a chemical change?

A
leaving a copper penny in vinegar until it turns green
B
boiling saltwater for several minutes until only solid salt remains
C
extracting iron filings from a sand mixture using a magnet
D
crushing a rock with a hammer to extract mineral deposits
5

Which event always involves a chemical change?

A
boiling
B
melting
C
conducting
D
burning
6

Which statement best describes chemical properties of matter?

A
Chemical properties, such as density, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure.
B
Chemical properties, such as reactivity, must be observed when a substance is in its natural state at room temperature and normal atmospheric pressure.
C
Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.
D
Chemical properties, such as boiling point, are generally observed as the identity of a substance changes and one or more new substances form.
7

Justin is making a snack. He toasts a piece of bread and spreads peanut butter and jelly on it. Then he cuts an apple into several slices and adds these to his plate. Next, Justin mixes a scoop of lemonade powder into a glass of water, mixes it, and adds ice.

A
one
B
two
C
three
D
four
8

Which statement best describes what happens during a chemical change?

A
Both the identity and the properties of a substance change.
B
Some properties of a substance change, but its identity remains the same.
C
The chemical properties of a substance change, but its physical properties remain the same.
D
The physical properties of a substance change, but its chemical properties remain the same.
9

In a science lab, Cash mixes two clear liquids together in a beaker. Bubbles are produced, and a white solid forms and settles to the bottom. He plans to heat the beaker over low heat and make more observations.

A
A physical change occurred, so if Cash heats it, the white solid will dissolve to form the original mixture of clear liquids.
B
A physical change occurred, so even if Cash heats it, the white solid will remain.
C
A chemical change occurred, so if Cash heats it, the white solid will dissolve to form the original mixture of clear liquids.
D
A chemical change occurred, so even if Cash heats it, the white solid will remain.
11

Jenna took an open bowl of leftover mashed potatoes from the refrigerator and noticed a difference in smell. She determined that chemical changes occurred since the potatoes were first placed there.

A
a change of odor
B
a decrease in temperature
C
a change in moisture content
D
a decrease in mass
12

Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation.

A
He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
B
He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
C
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
D
He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
13

What is the outcome of all chemical changes when two substances are combined?

A
A new substance forms with identical properties.
B
The two substances release an odor.
C
The two substances change color.
D
A new substance forms with different properties.
14

In a science demonstration, a teacher mixed zinc (Zn) with hydrogen chloride (HCl) in a flask and quickly attached a balloon over the mouth of the flask. Bubbles formed in the solution and the balloon inflated.

A
The Zn and HCl both retained their identity.
B
Either Zn or HCl, but not both, retained its identity.
C
Evaporation of one of the substances occurred.
D
One or more new substances formed.
15

Which statement describes all chemical changes, but not all physical changes?

A
Bubbles are produced.
B
A new substance forms.
C
Phase changes occur.
D
A color change occurs.
17

Which use of iron is due to its chemical properties?

A
producing colored sparks in fireworks
B
changing from liquid to gas at 2,862°C
C
conducting electricity and heat
D
changing from solid to liquid if heated to 1,538°C

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