Concepts: solutions: solubility, solute, solvent, aqueous, strong electrolytes,  weak electrolytes, nonelectrolytes.
If 15 grams of NaCl and 25 grams of KCl are melted and allowed to cool and form a solution, which of the following is true?
a. NaCl is the solvent and KCl is the solute.
*b. NaCl is the solute and KCl is the solvent.
c. NaCl is the solution and KCl is the solvent.
d. KCl is the solution and NaCl is the solvent.

          e. The moon is made of Philadelphia brand cream cheese.
Concepts: Types of solutions: liquid solutions, solid solutions, homogenous mixtures, alloys, dilute, concentrated,  saturated, supersaturated
Compound A is a liquid with a density of 0.8752 g/mL and it is miscible in water. Compound B is a liquid with a density of 0.9932 g/mL and it is miscible in C5H12. If 100 mL of A and 50 mL of B are mixed in a 250 mL graduated cylinder, which of the following descriptions of the resulting mixture would be predicted?
 a. A single phase homogeneous mixture of A and B is now present in the graduated cylinder.
*b. A heterogeneous mixture is present in the graduated cylinder with compound A floating on
      the top of compound B.
c. A heterogeneous mixture is present in the graduated cylinder with compound B floating on the
    top of compound A.
d. A homogeneous mixture is present in the graduated cylinder with compound B floating on the top    of compound A.

e. A homogeneous mixture is present in the graduated cylinder with compound A floating on the top     of compound B..
 Suppose we prepare a saturated solution of NaClO3 in 100 g of water at 80° C and then cool it 25° C. How          many grams of solid NaClO3 precipitates from solution? Look at the solubilty curve, text book page 525.
            a) 165 g     b) 100 g       c) 265 g       *d) 65 g     e) 230 g
Concepts:  Effect of temperature  and pressure on the solubility gases in a solution: Henry's Law.
The amount of oxygen dissolved in water will be greatest at
a. high temperature with high oxygen pressure above the solution.
b. high temperature with low oxygen pressure above the solution.
*c. low temperature with high oxygen pressure above the solution.

         d. low temperature with low oxygen pressure above the solution.
Concepts: molarity, molality, mass percentage, parts per million (ppm) and  mole fraction, and be able to use these concentration expressions in calculations.
An aqueous solution is prepared in which 3.30 mL of acetone, CH3COCH3, (d = 0.789 g/mL) is diluted with         water to a final volume of 75.0 mL to produce a solution with a density of 0.993 g/mL. What is the molality
of acetone in this solution?
           a)  0.601 CH3COCH3                    b) 0.597 m CH3COCH     c)  1.01 m CH3COCH3
           d)  36.2 m CH3COCH3               *e)  0.623 m CH3COCH3
How many grams of water are needed to give a 3.00 m NH3 solution if 15 moles of NH3 are to be dissolved in the water?
      a. 5       b. 4500      c. 4.5      d. 2000   *e. 5000

Determine the molarity of a 25.0% by mass CaCl2 solution that has a density of 1.228 g/mL.
a. 11.1    b. 0.25      *c. 2.77     d. 5.45    e. 22.6
What is the MOLALITY of a solution of 50.0 g of propanol (molar mass = 60.1 g/mol) in 152 mL water, if the density of water is 1.0 g/mL?
            *a) 5.47 m     b) 0.00547 m    c) 0.833 m     d) 0.183 m   e) none of these

How many grams of C12H22O11 are needed to dissolve in 250g of water to give a   2.337 x 10-1m solution? (M.W. C12H22O11 = 342.34)
a. 6.000g     b. 2.100g     c. 11.00g     *d. 20.00g     e. 1600g
Concepts: Convert concentration on one set of set of units or definition into any other expression of concentration, given the   density or MW when necessary.
What is the volume percent concentration of ethanol in a solution that is 24.0% by mass ethanol (d = 0.789         g/mL) in an aqueous solution with d = 0.963 g/mL?
            a) 24.0% ethanol              b) 19.7% ethanol             c) 40.0% ethanol          d) 28.6% ethanol
           * e) 29.3% ethanol
The term "proof" is defined as twice the percent by volume of pure ethanol in solution. Thus, a solution that is 95% (by VOLUME) ethanol is 190 proof. What is the MOLARITY of ethanol in a 92 proof ethanol/water solution?
density of ethanol = 0.80 g/cm3
density of water = 1.0 g/cm3
mol. wt. of ethanol = 46
               a) 0.46 M   *b) 0.80 M   c) 0.92 M   d) 8.0 M   e) 17 M
A solution of hydrogen peroxide is 30.0% H2O2 by mass and has a density of 1.11 g/cm3. The MOLARITY of the solution is:
            a) 7.94 M    b) 8.82 M    *c) 9.79 M        d) 0.980 M     e) none of these

A solution containing 296.6 g of Mg(NO3)2 per liter has a density of 1.114 g/mL. The MOLARITY of the solution is:
                     *a) 2.000 M        b) 2.446 M     c) 6.001 M    d) 1.805 M    e) none of these
A solution of NaCl is 11% NaCl. The mole fraction of NaCl is:

*a. 0.037       b. 0.025      c. 0.188       d. 0.083       e. 0.0037
What is the percent composition of NaCl in a solution containing 34.55 g of NaCl dissolved in 148.93 g of water?
How many g of AlCl3 are needed to prepare 250.0 ml of a 0.100 M solution?
a. 53.2mg       b. 25.0g    *c. 3.33g      d. 25.0   mg   e. 13.3g

An aqueous solution contains 64.0 g of ethanol ( C2H5OH ) in 122.0 g of solution. The mole fraction of ethanol is:
*a. 0.301   b. 0.432     c. 0.698    d. 0.205    e. none of these
Calculate the MOLALITY of C2H5OH in a water solution which is prepared by mixing 50.0 mL of C2H5OH with 100.0 mL of H2O at 20C. The density of the C2H5OH is 0.789 g/mL at 20C.
     a) 0.086 m   b) 0.094 m   c) 1.24 m  *d) 8.56 m  e) none of these

Concepts: Energy changes that occur in the solution process in terms of solute-solute, solvent-solvent and solute-solvent attractive forces. Describe the roll of disorder(entropy) in the solution process.
       During the solution process strong attractions between solute molecules will tend to make
           a)  DH > 0 and DV < 0.
           b)  DH < 0 and DV < 0.
           c)  DH < 0 and DV > 0.
           *d) DH > 0 and DV > 0.

         Which pair of substances would most likely form an ideal solution?
            a) water and sodium chloride
            b) CH3CH2CH3 and CH3CH2NH2
            *c) hexane and heptane
            d) CS2 and acetone
            e) hexane and benzene
A solution of two liquids, A and B, shows negative deviation from Raoult's Law. This means that

A solution of two liquids, A and B, shows negative deviation from Raoult's Law. This means that
a) the molecules of A interact strongly with other A-type molecules.
b) the two liquids have a positive heat of solution.
c) molecules of A interact weakly, if at all, with B molecules.
d) the molecules of A hinder the strong interaction between B molecules.

          *e) molecules of A interact more strongly with B than A with A or B with B.
Concepts: To explain the solubilities of substances in various solvents in terms of molecular structures and intermolecular forces.
Which of the following molecules could hydrogen bond with CH3OH (methanol)?
a. CH4       b. NH3      *c. NaH   d. He   e. SiH4

Which of the following molecules would be predicted to have the highest boiling point?
a. CH3-CH2-CH2-F      b. CH3-CH2-CH2-Cl    c. CH3-CH2-CH2-Br    *d. CH3-CH2-CH2-I

Which of the following would be predicted to be immiscible with water?
a. C3H7O   b. CH4O   c. C4H10O3      d. C6H14O3     e. *C5H12O

Concepts: Colligative property is and use the knowledge to calculate vapor pressure, boiling point,  freezing point and osmotic pressure of a solution when given concentration and necessary information.
Which of the following is NOT a colligative property?
a) freezing point depression    b) boiling point elevation    c) osmotic pressure   *d) solubility    e) two of the above

In order to calculate the freezing point of an ideal dilute solution of a single, nondissociating solute in a solvent, the minimum information one must know is: A solution is made by adding 0.100 mole of ethyl ether to 0.500 mole of ethyl alcohol. If the vapor pressures of ethyl ether and ethyl alcohol at 20C are 375 torr and 20.0 torr, respectively, the vapor pressure of the solution at 20C (assuming ideal behavior) is:
      *a) 79.2 torr   b) 316 torr       c) 47.5 torr   d) 395 torr   e) none of these
Vapor pressure (in torr) at 25 C Using the above data, calculate the total vapor pressure of a chloroform-benzene solution at 25C which contains 50.0 g CH3Cl and 50.0 g C6H6. Assume the solution behaves ideally.
        a) 67.8 torr      *b) 125 torr   c) 148 torr    d) 172 torr   e) none of these
Benzene and toluene form an ideal solution. At 298K, what is the mole fraction of benzene in the liquid that is in equilibrium with a vapor that has equal partial pressures of benzene and toluene? At 298K, the vapor pressures of pure benzene and pure toluene are 95 and 28 torr, respectively.
       a) 0.50     b) 0.77    *c) 0.23   d) 0.30   e) none of these
Pentane and hexane form an ideal solution. The components have the following properties:

 - - molar mass - density - bp - vapor pressure at 25C
pentane - 72 - 0.63 g/mL - 36C - 511 torr
hexane - 86 - 0.66 g/mL - 69C - 150 torr

What is the mole fraction of pentane (Xpentane) in the vapor in equilibrium at 25C with a pentane-hexane solution in which Xpentane = 0.30?
       a) Xpentane = 0.23    b) Xpentane = 0.29   *c) Xpentane = 0.59  d) Xpentane = 0.68     e) Xpentane = 0.77
Calculate the vapor pressure of a 1.00 molal solution of a nonvolatile solute in water at 50C. (The vapor pressure of water at 50 C is 92.5 torr.)

a)   101.1 torr   b)   75.6 torr    *c)  90.8 torr       d)      89.6 tott
Concepts: general trend will be with increasing or decreasing concentration.

The molal freezing point depression constants for benzene and water are 5.12 and 1.86 respectively. When 4.6 g of formic acid (HCOOH) is dissolved in 1.0 kg of benzene, the observed freezing point lowering is 0.26C. When the same amount of formic acid is dissolved in 1.0 kg of water, the freezing point is lowered by 0.19C. To explain these results, we must assume that:
When a nonvolatile solute is added to a volatile solvent, the solution vapor pressure ________________, the boiling point ________________, the freezing point ________________, and the osmotic pressure across a semipermeable membrane ________________. At a given temperature the vapor pressures of pure liquid benzene and toluene are 745 torr and 290 torr, respectively. A solution prepared by mixing benzene and toluene obeys Raoult's law. At this temperature the vapor pressure of benzene over a solution in which the mole fraction of benzene is equal to 0.340 is A solute added to a solvent raises the boiling point of the solution because  Which of the following substances would give a solution with a boiling point below that of pure water rather
         than above?
            a) sodium chloride (solid)
            *b) ethyl alcohol (liquid, b.p. 61oC)
            c) acetic acid (liquid, b.p. 118oC)
            d) sucrose sugar (solid)
            e) sulfuric acid (liquid, b.p. >300oC)
You can do a simple demonstration at home of the effects of osmosis on a biological cell: Immerse two
         chicken eggs in vinegar for a few days to dissolve the eggshells and expose the membranes, then place
         one egg in pure water and the other in syrup for a couple more days. Based on what you know about
         osmosis, what would you predict will happen to the eggs?
            a) The egg in water will shrink, while the egg in syrup will swell.
            b) Both eggs will shrink.
            c) Nothing will happen to the eggs.
            *d) The egg in water will swell, while the egg in syrup will shrink.
            e) Both eggs will swell.
Concept: Molecular weight from Colligative propeties
When 1.50 g of glutamic acid is dissolved in 100.0 g H2O, the resulting solution freezes at -0.190C. (Kf for H2O is 1.86C kg/mol.) The molar mass of glutamic acid is:
      *a) 14.7 g/mol        b) 1.50 g/mol     c) 189 g/mol    d) 28.0 g/mol   e) 147 g/mol
Thyroxine, an important hormone that controls the rate of metabolism in the body, can be isolated from the thyroid gland. If 0.455 g of thyroxine is dissolved in 10.0 g of benzene, the freezing point of the solution is 5.144C. Pure benzene freezes at 5.444C and has a value for the molal freezing point depression constant Kf of 5.12. What is the molar mass of thyroxine?
               a) 777,000 g/mol     *b) 777 g/mol       c) 2330 g/mol   d) 285 g/mol  e) 3760 g/mol
Concepts: Cncentration and molar mass of a nonvolatile nonelectrolyte from its effect on the colligative  properties of a solution.

Use data from Table 12.2 in the text to determine which solution below has the lowest freezing point.
            a) 1.00 m nonelectrolyte in benzene
            b) 1.00 m nonelectrolyte in nitrobenzene
            c) 1.00 m urea in H2O
            *d) 1.00 m KBr in H2O
            e) 1.00 m nonelectrolyte in acetic acid
Calculate the osmotic pressure, in torr, of 6.00 L of an aqueous 0.108 M solution at 30.C, if the solute concerned is totally ionized into three ions (e.g., it could be Na2SO4 or MgCl2).
       a) 8.05       *b) 6.12 x 103    c) 2.04 x 103     d) 3.68 x 104       e) none of these

The osmotic pressure, in torr, of a 0.0100 M solution of NaCl in water at 25C is APPROXIMATELY:
       a) 0.245      b) 15.6     *c) 372     d) 186    e) none of these
The vapor pressure of water at 90C is 0.692 atm. What is the vapor pressure (in atm) of a solution made by dissolving 1.00 mole of CsF(s) in 1.00 kg of water? Assume that Raoult's law applies. A 0.0100 M HC2H3O2 solution has i = 1.04. What can we conclude about the total concentration of  particles and the total concentration of ions?
           *a)  total concentration of particles = 0.0104 M; concentration of ions = 0.0008 M
           b)  total concentration of particles = 1.04 M; concentration of ions = 0.04 M
           c) total concentration of particles = 0.0096 M; concentration of ions = 0.0008 M
           d)  total concentration of particles = 0.0100 M; concentration of ions = 0.0004 M
            e) total concentration of particles = 0.0104 M; concentration of ions = 0.0004 M
Concepts: Colloid differs from a true solution and a suspension.