HElp with these Questions and how to do them?

[ajschick]

1. When 0.179 mol of urea, a nonelectrolyte whose MW = 60.1 and whose density = 1.48 g/cm3, is dissolved in 171 g of water (Kf = 1.86°C/molal), the molality of the solution is?

a 1.549 m.
b 1.047 m.
c 0.0629 m.
d 1.95 m.
e 0.0188 m

2. A bottle is labeled “Constant-boiling hydrochloric acid, 21.0 percent HCl by mass, density 1.1 g/mL.” Calculate the molarity of the HCl solution.

a 7.3 M
b 6.3 M
c 6.0 M
d 63 M
e 5.8 M

3.Calculate the molecular weight of a small protein if a 0.29-g sample dissolved in 147 mL of water has an osmotic pressure of 9.7 mmHg at 23°C.

a. 2.9 > 103 g/mol
b. 3.8 > 103 g/mol
c. 2.0 > 104 g/mol
d. 2.6 > 104 g/mol
e. none of these

4.Which of the following solutions would have the highest osmotic pressure?

a. 0.15 M NaCl, sodium chloride
b 0.15 M MgCl₂, calcium chloride
c 0.2 M CH₃COOH, acetic acid
d 0.2 M C₆H₁₂O₆, glucose
e 0.2 M C₁₂H₂₂O₁₁, sucrose

5.A solution consisting of 0.266 mol of methylbenzene (C₆H₅CH₃) in 252 g of nitrobenzene (C₆H₅NO₂) freezes at –1.4°C. Pure nitrobenzene freezes at 6.0°C. The molal freezing-point constant of nitrobenzene is

a 1.8°C molal-1.
b 3.5°C molal-1.
c 5.6°C molal-1.
d 7.0°C molal-1.
e 14.0°C molal- 1

6. The solubility of a gas in a liquid can always be increased by

a increasing the temperature of the solvent.
b decreasing the polarity of the solvent.
c decreasing the temperature of the gas above the solvent.
d decreasing the pressure of the gas above the solvent.
e increasing the pressure of the gas above the solvent.