Solutions

The symbol for molarity is

(M)

The symbol for molality is

(m)

In order to calculate molar mass from freezing or boiling point data, we need to know all of the following except: A. the Kf or Kb of the solvent B. the molar mass of the solvent C. the type of solute-electrolyte or not D. the number of particles in solution

B

An example of a liquid in solid solution is A. water in air B. zinc in copper C. mercury in silver and tin D. salt in water

C

One of the following is not a colligative property of water A. vapor pressure B. freezing point C. solubility D. boiling point

C

Vapor pressure lowering is best accomplished by a material that is all of the following except A. nonvolatile B. does not undergo chemical reaction C. slightly soluble D. does not escape into the gaseous phase

C

When NaCl is added to water, all of the follow occur except A. ions break off from the salt crystal B. ions are hydrated by water molecules C. ions precipitate D. ions recombine with the salt crystal

C

Temperature affects all of the following parameters except A. kinetic energy of the system B. increased frequency of collision between solute and solvent C. increased energy of collision D. change in molecular configuration

D

A concentrated solution contains a specified amount of solute. True or False?

False.

A greater surface area decreases the amount of material dissolved. True or False?

False.

Methylene glycol is used in many commercial antifreeze products. True or False?

False.

NaCl and methanol provide the same degree of boiling point elevation. True or False?

False.

Nonvolatile solutes readily escape into the vapor phase. True or False?

False.

Only freezing point data can be used to determine molar mass. True or False?

False.

Recrystallization from a supersaturated solution is very slow. True or False?

False.

Solubilities of gases are usually reported in grams/mL. True or False?

False.

Solutions are best prepared in a calibrated beaker. True or False?

False.

Stirring a solute affects the overall amount dissolved. True or False?

False.

The chemical nature of the solute is an important influence on vapor pressure lowering. True or False?

False.

When adding liquid solute and solvent together, volume is always conserved. True or False?

False.

A calibrated pipet improves the accuracy of preparing dilutions. True or False?

True.

Adding more water to a solution dilutes it. True or False?

True.

Addition of a solute decreases the vapor pressure of the solvent. True or False?

True.

Hydrated ions take up space in a solution. True or False?

True.

Ingredients in medicines and foods are often expressed as percentages. True or False?

True.

Many solutions do not involve water. True or False?

True.

Molality values are not affected by temperature. True or False?

True.

Moles of solute can be calculated using m x kg solvent. True or False?

True.

More NaCl can dissolve if more water is added to the solution. True or False?

True.

Pressure has very little effect on the solubility of solids or liquids. True or False?

True.

Some dissolved ions can recombine with the crystal. True or False?

True.

The choice of solvent has no effect on the value for the molality of a solution. True or False?

True.

The lowering of vapor pressure depends on the number of dissolved solute particles. True or False?

True.

The mass of the solute is needed in order to calculate molar mass. True or False?

True.

The solubility of most solid substances increases as the temperature increases. True or False?

True.

The vapor pressure of water depends on the number of particles dissolved in it. True or False?

True.

When a liquid evaporates readily, it has

a high vapor pressure

Volume units for dilution calculations

both sides of equation must have same units

Once we measure the freezing point depression, the next step is to

calculate molality of the solution

The solvent with the highest freezing point depression constant is

camphor

The solubility of gases

decreases as temperature increases

If the value for the number of ions formed is in error, then the molar mass will

depends on whether the value used is higher or lower than the real value

A solute affects the freezing point of a solvent by

disrupting the order of solvent molecules

A concentrated solution is one that

has a relatively large amount of solute

A dilute solution is one that

has a relatively small amount of solute

As pressure above the solvent _______, the amount of dissolved gas ________.

increases, increases

Molality is defined as moles of solute divided by

kg of solvent

Alcohol dissolved in water is an example of a _______ solution.

liquid in liquid

Molarity is determined by

moles of solute ÷ liters of solution

The rate at which a solute dissolves depends upon the _____ of the solute particles.

size

Use of a _____ solution is common in preparing dilutions of lower concentration.

stock

The relationship between gas solubility and pressure was developed by

the English chemist William Henry

Molal solutions are used in freezing point and boiling point calculations because

the concentration of molar solutions is affected by temperature

Mass percent is used when

the solute is a solid

Volume percent is calculated using the following formula

volume solute ÷ volume solution

The addition of NaCl to water

will reach a saturation point