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- A 0.95 m aqueous solution of an ionic compound with the formula MX has a freezing point of -3.0 °C. Calculate the van’t Hoff factor (i) for MX at this concentration.
문제 1
- Why do fish die when placed in a tank filled with water that has been boiled and then cooled?
문제 5
문제 30b
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)
문제 31
Which molecule would you expect to be more soluble in water: CH3CH2CH2OH or HOCH2CH2CH2OH?
- Which molecule would you expect to be more soluble in water: CCl4 or CH2Cl2?
문제 32
문제 35
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
문제 36
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
문제 40a
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. a. Is the dissolution of lithium iodide endothermic or exothermic?
문제 40b
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?
문제 40c
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.
문제 40d
When lithium iodide (LiI) is dissolved in water, the solution becomes hotter. d. Why does the solution form? What drives the process?
문제 41
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.
문제 42
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?
- Lithium iodide has a lattice energy of -7.3 * 10^2 kJ/mol and a heat of hydration of -793 kJ/mol. Find the heat of solution for lithium iodide and determine how much heat is evolved or absorbed when 15.0 g of lithium iodide completely dissolves in water.
문제 43
문제 44
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?
문제 45
A solution contains 35 g of NaCl per 100.0 g of water at 25°C. Is the solution unsaturated, saturated, or supersaturated? (Use Figure 14.11.)
문제 46
A KNO3 solution containing 35 g of KNO3 per 100.0 g of water is cooled from 40°C to 0°C. What happens during cooling? (Use Figure 14.11.)
문제 47
A KNO3 solution containing 35 g of KNO3 per 100.0 g of water is cooled from 40 °C to 0 °C. What happens during cooling? (Use Figure 14.11.)
문제 48
A KCl solution containing 38 g of KCl per 100.0 g of water is cooled from 60 °C to 0 °C. What happens during cooling? (Use Figure 14.11.)
- Why do some laboratory procedures involving oxygen-sensitive reactants or products call for using water that has been boiled and then cooled?
문제 49
- Scuba divers breathing air at increased pressure can suffer from nitrogen narcosis—a condition resembling drunkenness—when the partial pressure of nitrogen exceeds about 4 atm. What property of gas-water solutions causes this to happen? How can a diver reverse this effect?
문제 51
문제 52
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?
- Calculate the mass of nitrogen dissolved at room temperature in an 80.0-L home aquarium, assuming a total pressure of 1.0 atm and a mole fraction for nitrogen of 0.78.
문제 53
문제 57a
An aqueous NaCl solution is made using 102 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.)
문제 57b
An aqueous NaCl solution is made using 102 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.)
문제 57c
An aqueous NaCl solution is made using 102 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.)
문제 58a
An aqueous KNO3 solution is made using 55.3 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.)
문제 58b
An aqueous KNO3 solution is made using 55.3 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.)
문제 58c
An aqueous KNO3 solution is made using 55.3 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.)
문제 59
To what volume should you dilute 50.0 mL of a 3.00 M KI solution so that 25.0 mL of the diluted solution contains 2.55 g of KI?