Chemistry I - Ch 12 - 15 Study Guide

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____1.A heterogeneous mixture always contains

a. / only one substance.
b. / more than two substances.
c. / two or more substances that are visibly distinguishable.
d. / two or more substances that are not visibly distinguishable.

____2.Which of the following is a heterogeneous mixture?

a. / water / c. / whole wheat bread
b. / a sugar-water solution / d. / sugar

____3.Which of the following is a homogeneous mixture?

a. / water / c. / whole wheat bread
b. / a sugar-water solution / d. / sugar

____4.All of the following are homogeneous mixtures except

a. / soil. / c. / gasoline.
b. / a sugar-water solution. / d. / a salt-water solution.

____5.All of the following are heterogeneous mixtures except

a. / whole wheat bread. / c. / tap water.
b. / granite. / d. / an oil-water mixture.

____6.Which mixture contains visible particles that settle out unless the mixture is stirred?

a. / a colloid / c. / a solution
b. / a homogeneous mixture / d. / a suspension

____7.Which mixture contains particles that are in a dispersed phase and do not settle out?

a. / a colloid / c. / a solution
b. / a homogeneous mixture / d. / a suspension

____8.A metal solution is a(n)

a. / colloid. / c. / suspension.
b. / alloy. / d. / emulsion.

____9.A substance whose water solution is a good conductor of electricity is a(n)

a. / nonelectrolyte. / c. / nonpolar substance.
b. / electrolyte. / d. / solute.

____10.Which of the following is an electrolyte?

a. / sodium chloride / c. / pure water
b. / sugar / d. / glass

____11.A substance whose water solution is a poor conductor of electricityis a(n)

a. / polar substance. / c. / electrolyte.
b. / nonelectrolyte. / d. / ionic substance.

____12.Which of the following is a molecular substance whose aqueous solution carries an electric current?

a. / liquid hydrogen / c. / sugar
b. / hydrogen chloride / d. / iron

____13.Which of the following is a nonelectrolyte?

a. / sodium chloride / c. / sugar
b. / hydrogen chloride / d. / potassium chloride

____14.Which of the following does not increase the rate of dissolving a solid in water?

a. / raising the temperature of the water
b. / stirring the solution
c. / using larger pieces of solid
d. / crushing the solid

____15.Increasing the surface area of the solute

a. / increases the rate of dissolution.
b. / decreases the rate of dissolution.
c. / has no effect on the rate of dissolution.
d. / can increase, decrease, or have no effect on the rate of dissolution.

____16.Which of the following will dissolve most rapidly?

a. / sugar cubes in cold water / c. / powdered sugar in cold water
b. / sugar cubes in hot water / d. / powdered sugar in hot water

____17.Which of the following will dissolve most slowly?

a. / large salt crystals in unstirred water / c. / small salt crystals in unstirred water
b. / large salt crystals in stirred water / d. / small salt crystals in stirred water

____18.If the amount of solute present in a solution at a given temperature is less than the maximum amount that can dissolve at that temperature, the solution is said to be

a. / saturated. / c. / supersaturated.
b. / unsaturated. / d. / concentrated.

____19.A solute crystal is dropped into a solution containing dissolved solute. It falls to the bottom of the beaker and does not dissolve after vigorous stirring. What does this indicate about the solution?

a. / It is probably unsaturated. / c. / It is probably saturated.
b. / It is probably supersaturated. / d. / It is not at equilibrium.

____20.Which of the following is likely to produce crystals if disturbed?

a. / an unsaturated solution / c. / a saturated solution
b. / a supersaturated solution / d. / an electrolytic solution

____21.In the expression "like dissolves like," the word like refers to similarity in molecular

a. / mass. / c. / energy.
b. / size. / d. / polarity.

____22.Two immiscible substances

a. / exist together in one phase.
b. / will not separate on standing.
c. / dissolve freely in one another in any proportion.
d. / will not form a solution.

____23.Pressure has the greatest effect on the solubility of

a. / solids in liquids. / c. / gases in gases.
b. / liquids in liquids. / d. / gases in liquids.

____24.The solubility of gases in liquids

a. / increases with increasing pressure. / c. / decreases with increasing pressure.
b. / cannot reach equilibrium. / d. / does not depend on pressure.

____25.As temperature increases, solubility of gases in liquids

a. / increases. / c. / can increase or decrease.
b. / decreases. / d. / is not affected.

____26.As temperature increases, solubility of solids in liquids

a. / always increases. / c. / usually increases.
b. / always decreases. / d. / usually decreases.

____27.Which of the following expresses concentration?

a. / molality / c. / moles of solute per liter of solution
b. / molarity / d. / All of the above

____28.The concentration of a water solution of NaCl is 2.48 m, and it contains 806 g of water. How much NaCl is in the solution? (molar mass of NaCl = 58.44 g/mol)

a. / 2.00 g / c. / 117 g
b. / 89.3 g / d. / 224 g

____29.What mass of water must be used to make a 1.35 m solution that contains 8.20 mol of NaOH? (molar mass of NaOH = 40.00 g/mol)

a. / 6.07 kg / c. / 11.1 kg
b. / 7.44 kg / d. / 14.5 kg

____30.How many moles of ions are produced by the dissociation of 1 mol of MgCl2?

a. / 0 / c. / 2 mol
b. / 1 mol / d. / 3 mol

____31.How many moles of ions are produced by the dissociation of 1 mol of Al2(CO3)3?

a. / 2 mol / c. / 5 mol
b. / 4 mol / d. / 11 mol

____32.Colligative properties depend on

a. / the identity of the solute particles.
b. / the concentration of the solute particles.
c. / the physical properties of the solute particles.
d. / the boiling point and freezing point of the solution.

____33.The freezing point of an aqueous solution that contains a nonelectrolyte is –8.0ºC. What is the molal concentration of the solution? The molal freezing-point constant for water is

–1.86°C/m.

a. / 1.86 m / c. / 4.5 m
b. / 4.3 m / d. / 14.8 m

____34.What is the freezing-point depression of an aqueous solution of an electrolyte that produces three ions for every formula unit that dissociates if the electrolyte's concentration is 1.25 m?

Kf = –1.86°C/m.

a. / –1.25°C / c. / –5.58°C
b. / –1.86°C / d. / –6.98°C

____35.Compared with a 0.01 m sugar solution, a 0.01 m KCl solution has

a. / the same freezing-point depression.
b. / about twice the freezing-point depression.
c. / the same freezing-point elevation.
d. / about six times the freezing-point elevation.

____36.As electrolyte concentration decreases, freezing-point depression

a. / approaches the value calculated by assuming complete ionization.
b. / gets farther from the value calculated by assuming complete ionization.
c. / remains exactly equal to the value calculated by assuming complete ionization.
d. / approaches 0ºC.

____37.An Arrhenius acid contains

a. / hydrogen that does not ionize.
b. / hydrogen that ionizes to form hydrogen ions.
c. / oxygen that ionizes to form hydroxide ions.
d. / oxygen that ionizes to form oxygen ions.

____38.Which of the following is a strong acid?

a. / / c. / CH3COOH
b. / H2SO4 / d. / H3PO4

____39.Which of the following is a weak base?

a. / NH3 / c. / NaOH
b. / KOH / d. / Ba(OH)2

____40.A Brønsted-Lowry acid is a(n)

a. / electron-pair acceptor. / c. / proton acceptor.
b. / electron-pair donor. / d. / proton donor.

____41.A Brønsted-Lowry base is a(n)

a. / producer of OH– ions. / c. / electron-pair donor.
b. / proton acceptor. / d. / electron-pair acceptor.

____42.A Lewis acid is

a. / an electron-pair acceptor. / c. / a proton acceptor.
b. / an electron-pair donor. / d. / a proton donor.

____43.A Lewis base is a(n)

a. / producer of OH– ions. / c. / electron-pair donor.
b. / proton acceptor. / d. / electron-pair acceptor.

____44.In the reaction represented by the equation the conjugate acid of NH3 is

a. / HClO3. / c. / .
b. / . / d. / not shown.

____45.In the reaction represented by the equation , the conjugate base of H3O+ is

a. / H2O. / c. / CH3COO–.
b. / CH3COOH. / d. / not shown.

____46.In the reaction represented by the equation acts as a(n)

a. / acid. / c. / spectator species.
b. / base. / d. / salt.

____47.What is the pH of a neutral solution at 25ºC?

a. / 0 / c. / 7
b. / 1 / d. / 14

____48.The pH of an acidic solution is

a. / less than 0. / c. / greater than 7.
b. / less than 7. / d. / greater than 14.

____49.The pH of a basic solution is

a. / less than 0. / c. / greater than 7.
b. / less than 7. / d. / greater than 14.

Completion

Complete each statement.

50.When a liquid is insoluble in another liquid, the liquids are said to be ______.

51.A substance that does not dissolve in a solvent is said to be ______in that solvent.

52.The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature and pressure is called ______.

Problem

53.How many grams of NaOH are required to prepare 200. mL of a 0.450 M solution? (molar mass of NaOH = 40.00 g/mol)

54.Calculate the boiling-point elevation of a solution made from 15.0 g of a nonelectrolyte solute and 250.0 g of water. The molar mass of the solute is 50.0 g and Kb=0.51°C/m.

55.What concentration of ethylene glycol is needed to raise the boiling point of water to 105°C? (Kb=0.51°C/m)

56.Use the solubility curve to answer the following: (2 points each)

a.) What type of solution is formed when 50 g of KCl are added to 100 g of water at 30°C?

b.) How many grams of ammonium chloride are needed to make a saturated solution at 60°C in 100 grams of water?

c.) At what temperature is 80g of sodium nitrate soluble?

d.) Which salt has the lowest solubility at 40°C?

57.What is the molarity of a methanol solution that contains 25 g of methanol in 3.5 L of a solution? The molar mass of methanol is 32 g/mol.

58.Calculate the moles of camphor dissolved in 1.32 L of phenol. The molar mass of camphor is 152 g/mol and the molarity of phenol is 6.01 M.