Unit 6 Review

A substance such as water is described as polar because its molecules have -

• a neutral charge

• a positive end and a negative end

• two positive ends

• two negative ends

60 milliliters of vinegar is added to 40 milliliters of water. In this solution, the vinegar is identified as the -

• salt

• base

• solute

• solvent

Water is known as the "universal solvent." This is due to -

• the ratio of hydrogen to oxygen atoms

• the bonds between hydrogen and oxygen atoms

• the balance of OH- and H+ ions

• the unequal sharing of electrons between hydrogen and oxygen atoms

Tags

NGSS.HS-ESS2-5

A group of students are investigating gas solubility. Each group is given an amount of clear carbonated soda, hot water, cold water, four clear plastic cups, and a pair of goggles for each group member. Based on the materials provided, which question is most likely being investigated?

• How does mixing cold water with carbonated soda affect the solubility of gas?

• How does mixing warm water with carbonated soda affect the solubility of gas?

• How does temperature affect how quickly dissolved gas will escape from carbonated soda?

• How does temperature affect how quickly gas will dissolve in carbonated soda?

To increase the concentration of a solution, you would -

• increase the amount of solute

• increase the amount of solvent

• cool the solvent

• cool the solute

Tags

NGSS.HS-PS1-5

A crystal substance is dissolved into water. When a conductivity tester is placed in the water, a dim light is observed. The indicates that the crystal can be described as -

• polar

• nonpolar

• an electrolyte

• a non-electrolyte

A student is testing the rate of dissolution of a whole antacid tablet versus a crushed table. The crushed tablet would -

• take the same amount of time to dissolve as a whole antacid tablet

• not dissolve while the whole tablet would dissolve

• dissolve slower than a whole tablet

• dissolve quicker than a whole tablet

Tags

NGSS.HS-PS1-3

Nitrogen narcosis and the bends are disorders caused by nitrogen gas bubbles that form in the blood if the scuba diver surfaces too rapidly. Which of the following best explains the formation of the nitrogen bubbles in the diver's blood?

• The deeper water contains less dissolved oxygen.

• The solubility of gases decrease with increasing pressure.

• Increased pressure underwater causes more nitrogen gas than normal to be dissolved in the blood.

• Decreased pressure underwater causes less nitrogen gas than normal to be dissolved in the blood.

Solutions of ammonia (NH₃) and water can be purchased at most grocery stores. What best explains why ammonia can dissolve in water?

• Ammonia is a polar covalent compound.

• Ammonia is a nonpolar covalent compound.

• Ammonia is an ionic compound.

• Pure ammonia is a solid at room temperature.

Tags

NGSS.HS-PS1-1

According to the graph and rules of solubility above, temperature affects the solubility of which salt the most?

• NaCl

• NaNO₃

• KNO₃

• KCl