Chemistry Semester Review

While walking in the woods one morning after a light rain, Juan notices water droplets on the leaves of plants. Which of the following properties of water allows these water droplets to form?

• Versatility as a solvent

• Cohesive Behavior

• High specific heat

• Expansion upon freezing

The picture was taken from the banks of Lake Erie in the winter of 2013.

You can see that the exterior of the lake is covered with ice, while the center portion is not. The ice that is found on the exterior of the lake is floating on the water below. Why does the ice float?

• Water expands as it freezes, allowing in small air bubbles, so it floats.

• Water expands as it freezes, making it less dense that liquid water, so it floats.

• When water freezes it becomes polar, and so it will not mix with the non-polar water.

• When water freezes it becomes non-polar, and so it will not mix with the polar water.

Tags

NGSS.HS-ESS2-5

NGSS.HS-PS3-4

The picture below models one of the unique properties of water that contribute to Earth’s suitability as an environment for life.

When the oxygen atom in one water molecule is close to a hydrogen atom in another water molecule, what is most likely to happen?

• The two like charges of the water molecules will repel each other.

• The two water molecules will gain energy and vaporize, becoming water vapor.

• A Hydrogen bond will form drawing the two water molecules towards each other.

• An Oxygen bond will form between the two molecules and they will join together to form a larger molecule.

In Jacksonville Beach, the average daytime and nighttime temperatures usually only differ by 7-8°C, while temperatures in Ocala can differ by as much as 12-15°C.

What role does water play in keeping temperatures from fluctuating dramatically?

• Water is an acid.

• Water is a versatile solvent.

• Water acts as a buffer.

• Water has a high heat capacity.

Tags

NGSS.HS-ESS2-5

Maria, after finding no cold soda in the refrigerator, placed a can of soda in the freezer. She then proceeded to check her social networking site and forgot about the soda. Later that evening her brother went to get some ice and it was brown. Maria’s soda can had split open. What is the best explanation for what happened?

• As the water cooled, it adhered to the can, causing it to split.

• hen the water froze, it weakened the molecular bonds in the aluminum can.

• When the water froze, the space between hydrogen molecules expanded.

• As the water cooled, the surface tension of the water decreased and the can collapsed.

Tags

NGSS.MS-PS1-4

Matter that has a definite shape and a definite volume is

• a liquid.

• an element.

• a solid.

• a gas.

Tags

NGSS.MS-PS1-4

How should ice cream be classified?

• heterogeneous mixture.

• homogenous mixture.

• compound.

• Element.

A student drew the following concept map about matter. A different student was asked to critique the concept map. What would the best critique statement of this concept map?

• The word “matter” should be switched with the word “mixture” on the map.

• The words “homogenous” and “heterogeneous” should both be placed under the heading “pure substance”.

• The words “homogenous” and “heterogeneous” should both be placed under the heading “mixture”.

• Heterogeneous should be followed by the word “mixture”; homogeneous should be followed by the word “substance”.

There are four states of matter: solid, liquid, gas and plasma. In order for matter to change between the different states it must undergo a phase change. Which of the following phase changes require absorbing energy?

• vaporization and condensation

• condensation and freezing

• freezing and melting

• melting and vaporization

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A cup of liquid water loses energy to its environment. Which phase change might occur as a result of this loss of energy?

• boiling

• freezing

• sublimation

• melting

Tags

NGSS.HS-PS3-4