- #1
SAsurfa
- 10
- 0
Hey guys I was just wondering if you could help me out as I really struggle with these thermo questions and can never figure them out, cheers for any help :)
Question 1)Air consists of 20% oxygen and 80% nitrogen (by volume). Calculate the Gibbs energy of mixing in Joules if 8 x 3.9 L of pure nitrogen is mixed with 2 x 3.9 L of pure oxygen at 1 atm pressure.
I was thinking of using the fromula G = n*R*T*ln(Xa*ln(Xa) + Xb*ln(Xb)) but I can't see how the volumes come into it? I have no chemistry background at all and I think this is why I struggle
Question 2)What is the minimum amount of energy in Joules which would be required to separate 2 x 1.6 L of pure oxygen from 10 x 1.6 L of air at 1 atm pressure?
I think this will be the same as the first one but in reverse..
Question 3)Calculate the number of grams of oxygen dissolved in 7 L of water at 25°C when it is in equilibrium with the air above it at 1 atm. (Assume Henry’s law applies and use K=4.34 x 104 atm. Note that the partial pressure of oxygen in air is 0.2 atm and 1L of water has a mass 1kg).
Question 4)Liquid Acetone and Chloroform mixtures satisfy Raoults law approximately. If the vapour pressure at 35°C of pure acetone is 347 Torr and of pure Chloroform is 293 Torr, calculate the vapour pressure in Torr of a mixture with 28 % mole fraction of Chloroform.
Cheers guys, I need all the help I can get
Question 1)Air consists of 20% oxygen and 80% nitrogen (by volume). Calculate the Gibbs energy of mixing in Joules if 8 x 3.9 L of pure nitrogen is mixed with 2 x 3.9 L of pure oxygen at 1 atm pressure.
I was thinking of using the fromula G = n*R*T*ln(Xa*ln(Xa) + Xb*ln(Xb)) but I can't see how the volumes come into it? I have no chemistry background at all and I think this is why I struggle
Question 2)What is the minimum amount of energy in Joules which would be required to separate 2 x 1.6 L of pure oxygen from 10 x 1.6 L of air at 1 atm pressure?
I think this will be the same as the first one but in reverse..
Question 3)Calculate the number of grams of oxygen dissolved in 7 L of water at 25°C when it is in equilibrium with the air above it at 1 atm. (Assume Henry’s law applies and use K=4.34 x 104 atm. Note that the partial pressure of oxygen in air is 0.2 atm and 1L of water has a mass 1kg).
Question 4)Liquid Acetone and Chloroform mixtures satisfy Raoults law approximately. If the vapour pressure at 35°C of pure acetone is 347 Torr and of pure Chloroform is 293 Torr, calculate the vapour pressure in Torr of a mixture with 28 % mole fraction of Chloroform.
Cheers guys, I need all the help I can get