CHEM 121 - Ch 8 - Study guide

If 145 mL of 2.00 M KOH is diluted to 1.15 L, the resulting solution contains a. 0.334 moles of KOH b. 2.30 moles of KOH c. 3.34 moles of KOH d. 23.0 moles of KOH

a. 0.334 moles of KOH

Calculate the grams of NaOH present in 9.0 mL of a 8.0% (m/v) NaOH solution. a. 0.72 g b. 0.80 g c. 7.2 g d. 8.0 g

a. 0.72 g

Which of the following solutions would always contain 10.0 g of solute per 40.0 g of solvent? a. 20.0% (m/m) solution b. 25.0% (m/v) solution c. 25.0% (v/v) solution d. more than one correct response e. no correct response

a. 20.0% (m/m) solution

Which of the following statements concerning a saturated solution is incorrect? a. Undissolved solute must be present. b. Undissolved solute may or may not be present. c. Undissolved solute, if present, is continually dissolving. d. Undissolved solute, if present, is in equilibrium with dissolved solute.

a. Undissolved solute must be present.

A solution may contain a. only one solvent but many solutes b. many solvents but only one solute c. only one solvent and one solute d. many solvents and many solutes

a. only one solvent but many solutes

Choose the correct numerical value for the molarity from the response list for a solution using 50.0 mL of a 0.30 M solution to which 75.0 mL of solvent has been added. a. 0.10 M b. 0.12 M c. 0.25 M d. 0.30 M

b. 0.12 M

What is the molarity of a solution containing 16.7 grams of NH3 in 1.50 liters of solution? a. 0.0653 M b. 0.653 M c. 1.53 M d. 11.1 M

b. 0.653 M

What volume, in milliliters, of 4.0 M NaOH is needed to prepare 145 mL of 0.15 M NaOH by dilution? a. 3.9 ´ 103 mL b. 5.4 mL c. 2.6 ´ 10-4 mL d. 0.18 mL

b. 5.4 mL

Calculate the concentration in % (m/m) of a solution containing 20.5 g of LiF dissolved in 340.0 g of H2O. a. 1.14% (m/m) b. 5.69% (m/m) c. 6.03% (m/m) d. 6.42% (m/m)

b. 5.69% (m/m)

Which of the following statements concerning factors that affect solute solubility is incorrect? a. Most solid solutes become more soluble in water with increasing temperature. b. Most solid solutes become less soluble in water with decreasing pressure. c. Gaseous solutes become less soluble in water with increasing temperature. d. Gaseous solutes become more soluble in water with increasing pressure.

b. Most solid solutes become less soluble in water with decreasing pressure.

A colloidal dispersion differs from a suspension in that colloidal particles a. tend to settle at an appreciable rate b. are large enough to scatter light c. are large enough to be seen with the naked eye d. are large enough to be seen with a microscope

b. are large enough to scatter light

A crystal of solid NaCl is placed into an aqueous NaCl solution. It is observed that most, but not all, of the crystal dissolves. This means the original solution was a. supersaturated b. unsaturated c. dilute d. more than one correct response e. no correct response

b. unsaturated

In which of the following pairs of properties are both members of the pair colligative properties? a. density, boiling point b. vapor pressure, osmotic pressure c. solubility, freezing point d. more than one correct response e. no correct response

b. vapor pressure, osmotic pressure

A solution is made by dissolving 0.35 mole of LiI in enough water to give a final volume of 260.0 mL. What is the molarity of the solution? a. 0.091 M b. 0.67 M c. 1.3 M d. 2.6 M

c. 1.3 M

Which of the following statements is correct for 25.0 mL of 3.0 M NH3 solution? (NH3 has a molar mass of 17.0 g.) a. 25.0 mL of solvent is present. b. 0.75 moles of solute is present. c. 1.3 grams of solute is present. d. More than one correct response. e. No correct response.

c. 1.3 grams of solute is present.

Compared to pure water, a 1 M sugar-water solution will have a a. lower vapor pressure, lower boiling point and lower freezing point b. higher vapor pressure, higher boiling point and higher freezing point c. lower vapor pressure, higher boiling point and lower freezing point d. lower vapor pressure, lower boiling point and higher freezing point

c. lower vapor pressure, higher boiling point and lower freezing point

In a solution, the solvent is a. the substance being dissolved b. always a liquid c. the substance present in the greatest amount d. always water

c. the substance present in the greatest amount

A 0.300 M solution of LiOH that contains 0.500 mole of solute would have a volume, in milliliters, of a. 30.0 mL b. 60.0 mL c. 6.00 ´ 102 mL d. 1.67 ´ 103 mL

d. 1.67 ´ 103 mL

Which of the following types of interparticle attractions must be overcome in order for a solute to dissolve in a solvent? a. solute-solute b. solvent-solvent c. solute-solvent d. more than one correct response e. no correct response

d. more than one correct response

If two solutions with concentrations of 0.4 M sugar and 0.7 M sugar respectively are separated by a semipermeable membrane, during osmosis there is a net flow of a. sugar molecules from the concentrated to the dilute solution b. sugar molecules from the dilute to the concentrated solution c. water molecules from the concentrated to the dilute solution d. water molecules from the dilute to the concentrated solution

d. water molecules from the dilute to the concentrated solution