Question

1.What is the mole fraction of MgCl2 (MM=95.21 g/mole) in an aqueous solution that is 5.80 m MgCl2?

A. 0.104 B. 0.0946 C. 0.356 D. 0.553 E. none of these

2. A solution contains 0.144m Na2SO4 and has a measured freezing point of -0.606 degree celcius. What is the value of the Van’t Hoff factor, i? The freezing point depression constant for water is -1.86 degree celcius/m.

A. 3 B.0.326 C.2.26 D. 3.07. E. Cannot be determined

3.The vapor pressure of pure water at 45 degrees celcius is 71.9 mm Hg. What is the vapor pressure in mmHg of a mixture of 21.0 g sucrose (C12H22O11, MM=342.30 g/mole) and 79.0 g water?

A. 0.992. B. 15.1 C. 19.1 D. 70.9 E. None of these

Answer 1