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Problem 34a
Which of the following in each pair is likely to be more soluble in water: (a) cyclohexane (C6H12) or glucose (C6H12O6),
Problem 34b
Which of the following in each pair is likely to be more soluble in water: (b) propionic acid (CH3CH2COOH) or sodium propionate (CH3CH2COONa)
Problem 34c
Which of the following in each pair is likely to be more soluble in water: (c) HCl or ethyl chloride (CH3CH2Cl)? Explain in each case.
Problem 35c
Indicate whether each statement is true or false: (c) As you cool a saturated solution from high temperature to low temperature, solids start to crystallize out of solution if you achieve a supersaturated solution.
Problem 35d
Indicate whether each statement is true or false: (d) If you take a saturated solution and raise its temperature, you can (usually) add more solute and make the solution even more concentrated.
Problem 39a
(a) Calculate the mass percentage of Na2SO4 in a solution containing 10.6 g of Na2SO4 in 483 g of water.
Problem 39b
(b) An ore contains 2.86 g of silver per ton of ore. What is the concentration of silver in ppm?
- A solution is made containing 14.6 g of CH3OH in 184 g of H2O. Calculate (a) the mole fraction of CH3OH.
Problem 41
Problem 42a
A solution is made containing 20.8 g of phenol (C6H5OH) in 425 g of ethanol (CH3CH2OH). Calculate (a) the mole fraction of phenol,
Problem 43c
Calculate the molarity of the following aqueous solutions: (c) 25.0 mL of 3.50 M HNO3 diluted to 0.250 L.
- How many grams of sulfur (S) must be dissolved in 100.0 g of naphthalene (C10H8) to make a 0.12 m solution?
Problem 46
- A sulfuric acid solution containing 571.6 g of H2SO4 per liter of solution has a density of 1.329 g/cm³. Calculate (d) the molarity of H2SO4 in this solution.
Problem 47
Problem 48a
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (a) the mass percentage,
Problem 48c
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (c) the molality,
Problem 49b
The density of acetonitrile (CH3CN) is 0.786 g/mL and the density of methanol (CH3OH) is 0.791 g/mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of CH3CN. (b) What is the molality of the solution?
Problem 49c
The density of acetonitrile (CH3CN) is 0.786 g/mL and the density of methanol (CH3OH) is 0.791 g/mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of CH3CN. (c) Assuming that the volumes are additive, what is the molarity of CH3OH in the solution?
Problem 50a
The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 8.10 g of thiophene in 250.0 mL of toluene. (a) Calculate the mole fraction of thiophene in the solution.
Problem 51b
Calculate the number of moles of solute present in each of the following aqueous solutions: (b) 86.4 g of 0.180 m KCl,
Problem 51c
Calculate the number of moles of solute present in each of the following aqueous solutions: (c) 124.0 g of a solution that is 6.45% glucose (C6H12O6) by mass.
Problem 52a
Calculate the number of moles of solute present in each of the following solutions: (a) 255 mL of 1.50 M HNO3(aq),
Problem 52b,c
Calculate the number of moles of solute present in each of the following solutions: (b) 50.0 mg of an aqueous solution that is 1.50 m NaCl, (c) 75.0 g of an aqueous solution that is 1.50% sucrose (C12H22O11) by mass.
Problem 53b
Describe how you would prepare each of the following aqueous solutions from water and solid KBr: b. 125 g of 0.180 m KBr.
Problem 54a
Describe how you would prepare each of the following aqueous solutions from water and the solid solute: a. 1.50 L of 0.110 M (NH4)2SO4 solution;
Problem 55
Commercial aqueous nitric acid has a density of 1.42 g/mL and is 16 M. Calculate the percent HNO3 by mass in the solution.
Problem 57a
Brass is a substitutional alloy consisting of a solution of copper and zinc. A particular sample of red brass consisting of 80.0 % Cu and 20.0 % Zn by mass has a density of 8750 kg/m3. (a) What is the molality of Zn in the solid solution?
Problem 57b
Brass is a substitutional alloy consisting of a solution of copper and zinc. A particular sample of red brass consisting of 80.0 % Cu and 20.0 % Zn by mass has a density of 8750 kg/m3. (b) What is the molarity of Zn in the solution?
Problem 61
Suppose that you want to use reverse osmosis to reduce the salt content of brackish water containing 0.22 M total salt concentration to a value of 0.01 M, thus rendering it usable for human consumption. What is the minimum pressure that needs to be applied in the permeators (Figure 13.26) to achieve this goal, assuming that the operation occurs at 298 K?
Problem 62
Assume that a portable reverse-osmosis apparatus operates on seawater, whose effective concentration (the concentration of dissolved ions) is 1.12 M, and that the desalinated water output has an effective molarity of about 0.02 M. What minimum pressure must be applied by hand pumping at 297 K to cause reverse osmosis to occur?
- You make a solution of a nonvolatile solute with a liquid solvent. Indicate whether each of the following statements is true or false. (a) The freezing point of the solution is higher than that of the pure solvent. (b) The freezing point of the solution is lower than that of the pure solvent.
Problem 63
Problem 64a
You make a solution of a nonvolatile solute with a liquid solvent. Indicate if each of the following statements is true or false.
a. The solid that forms as the solution freezes is nearly pure solute.