[Maxtor]

I can solve other problems except these problems. Does anybody can solve?
Physical chemistry is too hard.

1) A solution of 1 mole of NaOH in 4.559 moles of water has a vapor pressure of 4.474 torr at 15 C, while the vapor pressure of pure water is 12.788 torr at the same temperature. Calculate the difference in the Gibbs free energy between 10 moles of water in this solution and in pure water.

2) The normal (normal = 1atm) melting point of mercury is -38.9C. What would its melting point be under a pressure of 500 atm? The enthalpy of fusion of mercury is 2.40 kJ/mol, and the difference in molar volume between solid and liquid mercury is 0.504 cm3/mol.
(1J = 9.870cm3atm)

3) It takes about 10-15 minutes to boil an egg in LA. It takes about 30-40 minutes to boil an egg in Denver. Why? Because water boils at a lower temperature in Denver given that the city is 5000 ft. above sea level. Calculate how much lower the boiling temperature of water is in Denver compared to in LA(at sea level, 1atm) assuming that the atmospheric pressure there is 0.6 atm.

The answer of 1) is -25.1 kJ and 2) is  -36.4 C. I don't have answer for 3).

[pantone159]

3) It takes about 10-15 minutes to boil an egg in LA. It takes about 30-40 minutes to boil an egg in Denver. Why? Because water boils at a lower temperature in Denver given that the city is 5000 ft. above sea level. Calculate how much lower the boiling temperature of water is in Denver compared to in LA(at sea level, 1atm) assuming that the atmospheric pressure there is 0.6 atm.

P.S.  The pressure in Denver is a lot higher than 0.6 atm, I figure around 0.82 atm.  You will notice a VERY significant difference in how hard it is to breathe (or, better, exercise) in Denver (1 mile=5280 feet), vs. at 13250 ft (4050 m) where the pressure is actually 0.6 atm.

[Donaldson Tan]

Forum policy requires you to show your attempt on the problem.

Here's a hint for the first problem:
Can you relate the ratio of the vapour pressures to the activity coefficient? Can you relate the activity coefficient to the molar gibbs' free energy?

Here's a hint for the second problem.
delta(h) = P.delta(V)