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Problem 0.48
Scuba divers breathing air at increased pressure can suffer from oxygen toxicity—too much oxygen in their bloodstream— when the partial pressure of oxygen exceeds about 1.4 atm. What happens to the amount of oxygen in a diver's bloodstream when he or she breathes oxygen at elevated pressures? How can this be reversed?
Problem 30
Pick an appropriate solvent from Table 13.3 to dissolve each substance. State the kind of intermolecular forces that would occur between the solute and solvent in each case. b. sodium chloride (ionic)
Problem 31
Which molecule would you expect to be more soluble in water: CH3CH2CH2OH or HOCH2CH2CH2OH?
Problem 33
For each compound, would you expect greater solubility in water or in hexane? Indicate the kinds of intermolecular forces that occur between the solute and the solvent in which the molecule is most soluble. a. glucose
Problem 34
For each compound, would you expect greater solubility in water or in hexane? Indicate the kinds of intermolecular forces that would occur between the solute and the solvent in which the molecule is most soluble. d. ethylene glycol
Problem 36a
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. a. Is the dissolution of lithium iodide endothermic or exothermic?
Problem 36b
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. b. What can you conclude about the relative magnitudes of the lattice energy of lithium iodide and its heat of hydration?
Problem 36c
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. c. Sketch a qualitative energy diagram similar to Figure 13.7 for the dissolution of LiI.
Problem 36d
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. d. Why does the solution form? What drives the process?
Problem 37
Silver nitrate has a lattice energy of -820 kJ/mol and a heat of solution of 22.6 kJ/mol. Calculate the heat of hydration for silver nitrate.
Problem 38
Use the data to calculate the heats of hydration of lithium chloride and sodium chloride. Which of the two cations, lithium or sodium, has stronger ion–dipole interactions with water? Why?
Problem 40
Potassium nitrate has a lattice energy of -163.8 kcal/mol and a heat of hydration of -155.5 kcal/mol. How much potassium nitrate has to dissolve in water to absorb 1.00⨉102 kJ of heat?
Problem 41
A solution contains 25 g of NaCl per 100.0 g of water at 25 °C. Is the solution unsaturated, saturated, or supersaturated? (Use Figure 13.11.)
Problem 42
A solution contains 32 g of KNO3 per 100.0 g of water at 25 °C. Is the solution unsaturated, saturated, or supersaturated? (Use Figure 13.11.)
Problem 43
A KNO3 solution containing 45 g of KNO3 per 100.0 g of water is cooled from 40 °C to 0 °C. What happens during cooling? (Use Figure 13.11.)Problem 44
A KCl solution containing 42 g of KCl per 100.0 g of water is cooled from 60 °C to 0 °C. What happens during cooling? (Use Figure 13.11.)
Problem 51a
An aqueous NaCl solution is made using 112 g of NaCl diluted to a total solution volume of 1.00 L. Calculate the molarity of the solution. (Assume a density of 1.08 g>mL for the solution.)
Problem 51b
An aqueous NaCl solution is made using 112 g of NaCl diluted to a total solution volume of 1.00 L. Calculate the molality of the solution. (Assume a density of 1.08 g>mL for the solution.)
Problem 51c
An aqueous NaCl solution is made using 112 g of NaCl diluted to a total solution volume of 1.00 L. Calculate the mass percent of the solution. (Assume a density of 1.08 g>mL for the solution.)
Problem 52a
An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted to a total solution volume of 2.00 L. Calculate the molarity of the solution. (Assume a density of 1.05 g>mL for the solution.)
Problem 52b
An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted to a total solution volume of 2.00 L. Calculate the molality of the solution. (Assume a density of 1.05 g>mL for the solution.)
Problem 52c
An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted to a total solution volume of 2.00 L. Calculate the mass percent of the solution. (Assume a density of 1.05 g>mL for the solution.)
Problem 53
To what volume should you dilute 50.0 mL of a 5.00 M KI solution so that 25.0 mL of the diluted solution contains 3.05 g of KI?
Problem 55
Silver nitrate solutions are often used to plate silver onto other metals. What is the maximum amount of silver (in grams) that can be plated out of 4.8 L of an AgNO3 solution containing 3.4% Ag by mass? Assume that the density of the solution is 1.01 g>mL.
Problem 56
A dioxin-contaminated water source contains 0.085% dioxin by mass. How much dioxin is present in 2.5 L of this water? Assume a density of 1.00 g>mL.
Problem 58
Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011% Pb by mass. How much of the water (in mL) contains 150 mg of Pb? (Assume a density of 1.0 g>mL.)
Problem 62b
Describe how to prepare each solution from the dry solute and the solvent. b. 125 g of 0.100 m NaNO3
Problem 62c
Describe how to prepare each solution from the dry solute and the solvent. c. 125 g of 1.0% NaNO3 solution by mass
Problem 64a
A solution is prepared by dissolving 20.2 mL of methanol (CH3OH) in 100.0 mL of water at 25 °C. The final volume of the solution is 118 mL. The densities of methanol and water at this temperature are 0.782 g>mL and 1.00 g>mL, respectively. For this solution, calculate the concentration in each unit. a. molarity
Problem 64b
A solution is prepared by dissolving 20.2 mL of methanol (CH3OH) in 100.0 mL of water at 25 °C. The final volume of the solution is 118 mL. The densities of methanol and water at this temperature are 0.782 g/mL and 1.00 g/mL, respectively. For this solution, calculate the concentration in each unit. b. molality
