chem.13
How does increasing the partial pressure of a gas above a solution affect the solubility of the gas?
Gas solubility increases.
Molality is defined as the ratio of moles of solute dissolved in:
1 kilogram of solvent.
State Henry's Law.
At a given temperature, the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.
Give an example of a suspension.
Muddy water or sand in water.
The decrease in a solution's vapor pressure is proportional to the number of particles the solute makes in solution. This statement describes:
Vapor Pressure Lowering
Give an example of a strong electrolyte mentioned in the notes.
Sodium chloride (NaCl).
Why does stirring or shaking increase the rate of solvation?
It moves dissolved particles away allowing new collisions.
For nonelectrolytes, the magnitude of the boiling point elevation is directly proportional to the solution's:
Molality
What is the formula for Henry's Law?
S1/P1 = S2/P2
What is a saturated solution?
A solution that contains the maximum amount of dissolved solute for a given amount of solvent at a specific temperature and pressure.
For nonelectrolytes, the value of the freezing point depression is directly proportional to the solution's what?
Molality.
Two liquids that are soluble in each other in any proportion are described as:
Miscible liquids
To form a supersaturated solution, a saturated solution is formed at high temperature and then:
Slowly cooled
What term describes a solution containing a large amount of solute qualitatively?
Concentrated.
What is a key characteristic of colligative properties?
They are affected by the number of particles but not by the identity of dissolved solute particles.
When diluting a solution, what remains unchanged?
The total number of moles of solute.
Compounds that dissociate in water to form solutions that conduct electric current are called:
Electrolytes.
Molarity is defined as the number of moles of solute dissolved per:
Liter of solution.
What is the term for a mixture that has a uniform composition throughout?
Homogeneous mixture or solution.
What are concentrated solutions of standard molarity called?
Stock solutions.
Define mole fraction.
The ratio of the number of moles of solute in solution to the total number of moles of solutes and solvent.
What is the 'heat of solution'?
The overall energy change that occurs during solution formation.
What is solvation in water specifically called?
Hydration.
Which of the following is NOT a colligative property?
Solution color intensity.
Molecular compounds that do not ionize when dissolved are called:
Nonelectrolytes
In a solution, what is the substance that dissolves called?
Solute substance
What is the process of surrounding solute particles with solvent particles to form a solution called?
Solvation
What is the most common solvent among liquid solutions?
Water.
What effect does adding a nonvolatile solute have on the solvent's vapor pressure?
It lowers the solvent's vapor pressure.
How does increasing temperature affect the solubility of most solid substances?
Solubility increases.
What unit is 'm' read as for molality?
Molal.
What is the particle size range for a colloid?
Between 1 nm and 100 nm
For a solution to form, the attractive forces between the solvent and solute particles must be:
Stronger than the forces holding solute particles.
Which quantity is required to calculate molality?
Mass of solvent in kilograms.
What is the 'molal boiling point elevation constant' (Kb)?
The difference in boiling point between 1m nonvolatile, nonelectrolyte solution and a pure solvent.
Define boiling point elevation.
The temperature difference between a solution's boiling point and a pure solvent's boiling point.
What happens to the rate of solvation when the temperature of the solvent increases?
It increases.
Write the dilution equation.
M1V1 = M2V2.
Do colloids settle out if left undisturbed?
No.
If a solution is 2.5M, how is this read?
2.5 molar solution.
Strong electrolytes are characterized by which of the following?
They almost completely dissociate in solution.
Give an example of a common solvent used in many medicines.
Ethanol.
Which characteristic distinguishes a suspension from a colloid?
Particles are visible to the naked eye.
Define a heterogeneous mixture.
A mixture that doesn't have a uniform composition and in which the individual substances remain distinct.
Which type of solution contains less dissolved solute than a saturated solution at a given temperature and pressure?
Unsaturated solution
A 1m solution of NaCl contains how many moles of solute particles?
Two moles
Which of the following best describes a heterogeneous mixture?
Individual substances remain distinct.
What is freezing point depression?
The difference in temperature between a solution's freezing point and the pure solvent's freezing point.
What is the formula for calculating percent by mass concentration?
(Mass of solute / Mass of solution) x 100
Which property is shared by both suspensions and colloids?
Considered non-uniform mixtures.