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Glacial acetic acid has a melting point of
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Student Solutions Manual for Ball's Physical Chemistry, 2nd
- What quantity of ethylene glycol, HOCH2CH2OH, must be added to 125 g of water to raise the boiling point by 1.0 C? Express the answer in grams.arrow_forwardInsulin is a hormone responsible for the regulation of glucose levels in the blood. An aqueous solution of insulin has an osmotic pressure of 2.5 mm Hg at 25C. It is prepared by dissolving 0.100 g of insulin in enough water to make 125 mL of solution. What is the molar mass of insulin?arrow_forward6-111 As noted in Section 6-8C, the amount of external pressure that must be applied to a more concentrated solution to stop the passage of solvent molecules across a semipermeable membrane is known as the osmotic pressure The osmotic pressure obeys a law similar in form to the ideal gas law (discussed in Section 5-4), where Substituting for pressure and solving for osmotic pressures gives the following equation: RT MRT, where M is the concentration or molarity of the solution. (a) Determine the osmotic pressure at 25°C of a 0.0020 M sucrose (C12H22O11) solution. (b) Seawater contains 3.4 g of salts for every liter of solution. Assuming the solute consists entirely of NaCl (and complete dissociation of the NaCI salt), calculate the osmotic pressure of seawater at 25°C. (c) The average osmotic pressure of blood is 7.7 atm at 25°C. What concentration of glucose (C6H12O6) will be isotonic with blood? (d) Lysozyme is an enzyme that breaks bacterial cell walls. A solution containing 0.150 g of this enzyme in 210. mL of solution has an osmotic pressure of 0.953 torr at 25°C. What is the molar mass of lysozyme? (e) The osmotic pressure of an aqueous solution of a certain protein was measured in order to determine the protein's molar mass. The solution contained 3.50 mg of protein dissolved in sufficient water to form 5.00 mL of solution. The osmotic pressure of the solution at 25°C was found to be 1.54 torr. Calculate the molar mass of the protein.arrow_forward
- 3. (a) The Lattice enthalpy for the solid ionic compound AgBr is +900. kJ/mole. Write the chemical equation that corresponds to the Lattice Enthalpy for AgBr(s) in the space above. Then explain in your own words why this is a large positive number. (b) The hydration enthalpy for AgBris -821 kJ/mole. Write the chemical equation that corresponds to the Hydration Enthalpy for AgBr(s) in the space above. Then explain in your own words why this is a large negative number. (c) Would you expect this compound to be soluble in water? Why/Why not? Calculate anything you need in order to figure this out, and explain your answer.arrow_forward(a) Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. CaCl₂(s) Cal₂(s) Lattice Energy -2247 kJ/mol -2059 kJ/mol * AH soln -46 kJ/mol -104 kJ/mol *Lattice energy is defined as the energy change for the process M*(g) + X¯(g) → MX(s). calcium chloride kJ/mol kJ/mol calcium iodide (b) Based on your answers to part (a), which ion, CI or I, is more strongly attracted to water? chloride iodide Explain. The enthalpy of hydration for CaCl₂ is |---Select--- exothermic than for Cal₂. Any differences must be due to differences in hydrations between CI and I¯.arrow_forwardCarbon disulfide 1CS22 boils at 46.30 °C and has a density of 1.261 g>mL. (a) When 0.250 mol of a nondissociating solute is dissolved in 400.0 mL of CS2, the solution boils at 47.46 °C. What is the molal boiling-point-elevation constant for CS2? (b) When 5.39 g of a nondissociating unknown is dissolved in 50.0 mL of CS2, the solution boils at 47.08 °C. What is the molar mass of the unknown?arrow_forward
- (a) Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. CaCl ₂ (s) Cal₂(s) Lattice Energy -2247 kJ/mol -2059 kJ/mol * AH soln -46 kJ/mol -104 kJ/mol *Lattice energy is defined as the energy change for the process M*(g) + X¯(g) → MX(s). calcium chloride calcium iodide kJ/mol kJ/molarrow_forward(a) What is the charge density of an ion, and what two prop-erties of an ion affect it?(b) Arrange the following in order of increasing charge density:(c) How do the two properties in part (a) affect the ionic heat of hydration, ΔH(hydr)?arrow_forwardThe lattice energy of KCI is -690. kJ/mol, and the enthalpy of hydration is -707 kJ/mol. (Recall that lattice energy is defined as the energy change for the process M*(g) + X¯(g) → MX(s).) (a) Calculate the enthalpy of solution (in kJ/mol) per mole of solid KCI. kJ/mol (b) Describe the process to which this enthalpy change applies. ΔΗ. refers to the heat released or gained when a a solute dissolves in a solvent soln ↑arrow_forward
- The common laboratory solvent diethyl ether (ether) is often used to purify substances dissolved in it. The vapor pressure of diethyl ether, CH3CH,0CH,CH3, is 463.57 mm Hg at 25 °C. In a laboratory experiment, students synthesized a new compound and found that when 34.94 grams of the compound were dissolved in 220.4 grams of diethyl ether, the vapor pressure of the solution was 449.89 mm Hg. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight of this compound? diethyl ether = CH3CH,0CH,CH3 = 74.12 g/mol. MW g/molarrow_forwardOsmotic pressure can be very useful for estimating the molecular weights of macromolecules for whom a molecular formula may not be available as it can provide greater precision in the measurement. (a) 1.364 g of a protein with molecular mass 1.78 × 104 g/mol is dissolved in enough water to create 100.0 mL of solution at 298 K. What would be the expected osmotic pressure (in bars) of this solution? (b) If 1.853 g of a protein are dissolved in enough water to make up 100.0 mL of solution at 298 K, then the osmotic pressure is observed to be 2.521 torr (3.361 × 10-³ bar). What is the molar mass (g/mol) of the protein?arrow_forwardC2H;OH, is 44 torr 65. The vapor pressure of methanol, CH3OH, is 94 torr at 20 °C. The vapor pressure of ethanol, C2H5OH, is 44 torr at the same temperature. (a) Calculate the mole fraction of methanol and of ethanol in a solution of 50.0 g of methanol and 50.0 g of ethanol. (b) Ethanol and methanol form a solution that behaves like an ideal solution. Calculate the vapor pressure of methanol and of ethanol above the solution at 20 °C. (c) Calculate the mole fraction of methanol and of ethanol in the vapor above the solution.arrow_forward
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