eQuizShow

Solutions

Dissolution processes

Question:

The term for a substance that is dissolved into a solution.


Answer:

solute



Question:

The term for a substance that dissolves another substance.


Answer:

solvent



Question:

Why is it that some substances cannot be dissolved by water?


Answer:

Water is a polar solvent. Materials that are non-polar will likely not be dissolved by water since water is not attracted to their molecules enough to dissolve them. (Like dissolves like)



Question:

What dissolution process occurs when an ionic compound is separated into free ions by the action of a polar solvent?


Answer:

dissociation



Question:

What dissolution process occurs when sugar crystal (a polar-covalent compound) is separated into individual molecules by the action of a polar solvent?


Answer:

dispersion



Types of solutions

Question:

Term for a solution in which more solute can be dissolved.


Answer:

unsaturated



Question:

The measure of the amount of a certain solute that can be dissolved into a given amount of a certain solvent at a certain temperature.


Answer:

solubility



Question:

Any substance that produces a solution containing free ions when dissolved.


Answer:

electrolyte



Question:

A solution in which the amount of solute dissolved exceeds its solubility at that temperature.


Answer:

supersaturated



Question:

Identify two factors that affect the solubility of a gaseous solute in a liquid solvent.


Answer:

1) the temperature of the solvent (higher temp = less solubility for gasses)

2) the pressure of the gas (higher pressure = greater solubility)



Concentration

Question:

How is the molarity of a solution determined?


Answer:

Dividing the moles of solute by the volume of the solution.



Question:

A solution that is holding the maximum amount of solute at its present temperature.


Answer:

saturated



Question:

This term refers to the act of adding solvent to a solution in an effort to reduce the concentration of the solute.


Answer:

dilution



Question:

The solubility of sodium chloride is 36 g per 100 g of water at 20 C.

A) what is the concentration (in % by mass) of a saturated salt-water solution at 20 C?

B) How many grams of salt can be dissolved into 200 g of water at 20 C?

C) How would the answer to part B change if the 200 g of water was heated well above 20 C?


Answer:

A) 36 %

B) 36 x 2 = 72 grams

C) It would become greater than 72 grams.



Question:

When a salt is dissolved into water, decribe three properties of water that change.


Answer:

1) becomes conductive

2) melting / freezing point drops

3) boiling point increases



The pH scale

Question:

What is the pH of pure water (defined as "neutral")


Answer:

7



Question:

A) A pH below 7 defines this type of solution.

B) A pH above 7 defines this type of solution.


Answer:

A) acidic

B) basic (alkaline)



Question:

pH is calculated based on the concentration of what in a solution?


Answer:

hydronium ions



Question:

What is the pH value for a solution with a hydronium ion concetration equal to 1 x10{-9} or   1 E-9?


Answer:

9



Question:

To increase the pH of a solution by 1 on the pH scale would require a(n)  {increase / decrease} of hydronium ion by a factor of __________.


Answer:

decrease ; 10



Acids and Bases

Question:

What characteristic defines all acids?


Answer:

They produce hydronium ions when dissolved in solution.



Question:

What characteristic defines all bases?


Answer:

They form hydroxide ions when dissolved in a solution.



Question:

What dissolution process results in the release of free protons when an acid is dissolved into solution?


Answer:

ionization



Question:

What is a "neutralization" reaction? What products are formed?


Answer:

A reaction between an acid and a base.

Water and a salt are produced.



Question:

Differentiate between  "strong" acid and a "weak" acids and bases.


Answer:

Strong acids and bases almost completely ionize in solution, whereas a weak acid or base only partially ionzizes in a solution to form hydronium or hydroxide ions.