A mixture of liquids A and B exhibits ideal behavior. At 84 °C, the total vapor pressure of a solution containing 1.2 moles of A and 2.3 moles of B is 321 mmHg. Upon the addition of another mole of B to the solution, the vapor pressure increases to 347 mmHg. Calculate the vapor pressures of pure A and B at 84 °C. Part 1 of 2 Be sure your answer has the correct number of significant digits. P = mmHg Part 2 of 2 pº = 0 Be sure your answer has the correct number of significant digits. mmHg x10 X 0

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?

Arrange 0.10 m aqueous solutions of the following solutes in order of decreasing freezing point and boiling point. (a) Al(ClO3)3(b) CH3OH (c) (NH4)2Cr2O7 (d) MgSO4

Ice Cream A rock salt (NaCl), ice, and water mixture isused to cool milk and cream to make homemade icecream. How many grams of rock salt must be added towater to lower the freezing point by 10.0°C?

Calculate the freezing point and normal boiling points of each of the following aqueous solutions. (a) 2.63 m acetic acid (b) 33.0 % by mass lactose, C12H22O11 (c) 32.15 mL of ethylene glycol, C2H6O2(d=1.113g/mL) in 624 mL of water (d=1.00g/mL)

a. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. Lattice Energy Hsoln CaCl2(s) 2247kj/mol 46kj/mol Cal2(s) 2059kj/mol 104kj/mol b. Based on your answers to part a, which ion, Cl or I, is more strongly attracted to water?

Calculate the freezing point of 525 g of water that contains 25.0 g of NaCl. Assume i, the vant Hoff factor, is 1.85 for NaCl.

Which of the following salts, Li2SO4 or Cs2SO4, is expected to have the more exothermic enthalpy of hydration?

Consider two hypothetical pure substances, AB(s) and XY(s). When equal molar amounts of these substances are placed in separate 500-mL samples of water, they undergo the following reactions: AB(s)A+(aq)+B(aq)XY(s)XY(aq) a Which solution would you expect to have the lower boiling point? Why? b Would you expect the vapor pressures of the two solutions to be equal? If not, which one would you expect to have the higher vapor pressure? c Describe a procedure that would make the two solutions have the same boiling point. d If you took 250 mL of the AB(aq) solution prepared above, would it have the same boiling point as the original solution? Be sure to explain your answer. e The container of XY(aq) is left out on the bench top for several days, which allows some of the water to evaporate from the solution. How would the melting point of this solution compare to the melting point of the original solution?

The solubility of NaCl in water at 100 C is 39.1 g/100. g of water Calculate the boiling point of this solution. (Assume i = 1.85 for NaCl.)