There are two solutions of eugenol (b.p. = 248 °C, v.p. = 4 torr at 100° C) and water (b.p = 100 °C and v.p. = 760 torr at 100 °C). The molar fraction of eugenol and water in solution A are 0.80 and 0.20 respectively. The molar fraction of eugenol and water in solution B are 0.20 and 0.80 respectively. Which statement is true regarding the boiling point of the two solutions? (Hint: eugenol and water are immiscible) A. Solution A will have a higher boiling point. B. Solution B will have a higher boiling point. C. Both solutions will boil at the same temperature. D. The relative boiling points cannot be determined with the given information. A. Solution A will have a higher boiling point. OB. Solution B will have a higher boiling point. C. Both solutions will boil at the same temperature. OD. The relative boiling points cannot be determined with the given information.

A forensic chemist is given a white solid that is suspected of being pure cocaine (C17H21NO4, molar mass = 303.35 g/mol). She dissolves 1.22 0.01 g of the solid in 15.60 0.01 g benzene. The freezing point is lowered by 1.32 0.04C. a. What is the molar mass of the substance? Assuming that the percent uncertainty in the calculated molar mass is the same as the percent uncertainty in the temperature change, calculate the uncertainty in the molar mass. b. Could the chemist unequivocally state that the substance is cocaine? For example, is the uncertainty small enough to distinguish cocaine from codeine (C18H21NO3, molar mass = 299.36 g/mol)? c. Assuming that the absolute uncertainties in the measurements of temperature and mass remain unchanged, how could the chemist improve the precision of her results?

A 1.00 mol/kg aqueous sulfuric acid solution, H2SO4,freezes at 4.04 C. Calculate i, the vant Hoff factor,for sulfuric acid in this solution.

The organic salt [(C4H9)4N][ClO4] consists of the ions (C4H9)4N+ and ClO4. The salt dissolves in chloroform. What mass (in grams) of the salt must have been dissolved if the boiling point of a solution of the salt in 25.0 g chloroform is 63.20 C? The normal boiling point of chloroform is 61.70 C and Kb = 3.63 C kg mol1. Assume that the salt dissociates completely into its ions in solution.

A solution is made by dissolving 0.455 g of PbBr2 in 100 g of H2O at 50C. Based on the data in Table 8-1, should this solution be characterized as a. saturated or unsaturated b. dilute or concentrated

Carbon tetrachloride (CCl4) and benzene (C6H6) form ideal solutions. Consider an equimolar solution of CCl4 and C6H6 at 25C. The vapor above the solution is collected and condensed. Using the following data, determine the composition in mole fraction of the condensed vapor. Substance Gfo C6H6(l) 124.50 kJ/mol C6H6(g) 129.66 kJ/mol CCI4(l) 65.21 kJ/mol CCI4,(g) 60.59 kJ/mol

Predict the relative solubility of each compound in the two solvents, based on the intermolecular attractions. (a) Is potassium iodide more soluble in water or in methylene chloride (CH2Cl2)? (b) Is toluene (C6H5CH3) more soluble in benzene (C6H6) or in water? (c) Is ethylene glycol (C2H4(OH)2) more soluble in hexane (C6H14) or in ethanol (C2H5OH)?

Predict the relative solubility of each compound in the two solvents, on the basis of intermolecular attractions. (a) Is Br2 more soluble in water or in carbon tetrachloride? (b) Is CaCl2 more soluble in water or in benzene (C6H6)? (c) Is chloroform (CHCl3) more soluble in water or in diethyl ether [(C2H5)2O]? (d) Is ethylene glycol (HOCH2CH2OH) more soluble in water or in benzene (C6H6)?

Vapor-pressure lowering is a colligative property, as are freezing-point depression and boiling-point elevation. What is a colligative property? Why is the freezing point depressed for a solution as compared to the pure solvent? Why is the boiling point elevated for a solution as compared to the pure solvent? Explain how to calculate T for a freezing-point depression problem or a boiling-point elevation problem. Of the solvents listed in Table 10-5, which would have the largest freezing-point depression for a 0.50 molal solution? Which would have the smallest boiling-point elevation for a 0.50 molal solution? A common application of freezing-point depression and boiling-point elevation experiments is to provide a means to calculate the molar mass of a nonvolatile solute. What data are needed to calculate the molar mass of a nonvolatile solute? Explain how you would manipulate these data to calculate the molar mass of the nonvolatile solute.

What is the total vapor pressure at 20C of a liquid solution containing 0.30 mole fraction benzene, C6H6, and 0.70 mole fraction toluene, C6H5CH3? Assume that Raoults law holds for each component of the solution. The vapor pressure of pure benzene at 20C is 75 mmHg; that of toluene at 20C is 22 mmHg.