[offlinedoctor]

Q. NH4CL(s) -> NH3(g) + HCl(g)

i) Total Partial Pressure was 4.4atm, calculate Kp.
 
What I did was:

Total M(NH4Cl) = 53.5
Total M(NH3) = 17
Total M (HCl) = 36.5

There NH3 makes up (17/53.5 x 100) = 31.8% of total pressure.
         HCl makes up (36.5/53.5 x 100) = 68.2% of total pressure

Therefore their partial pressures:
P(NH3) = 0.318 x 4.4 = 1.4atm
P(HCl) = 0.682 x 4.4 = 3 atm

Therefore Kp = 1.4 x 3 = 4.2.

Is that the right way to go about the question?

Also, could someone show me to how approach this problem revolving around the Henrys Law? Textbooks seem to lack these styles of questions.

'Mole fraction of CO2 in aqueous solution is 3.6x10^-5, assuming carbon dioxide in solution is in equilibrium with atmosphere, what is the partial pressure of CO2 in solution? Kh = 1.63x10^3'.

[Borek]

Q. NH4CL(s) -> NH3(g) + HCl(g)

i) Total Partial Pressure was 4.4atm, calculate Kp.

No such thing as "total partial pressure". Are you sure it wasn't just "total"?

There NH3 makes up (17/53.5 x 100) = 31.8% of total pressure.
         HCl makes up (36.5/53.5 x 100) = 68.2% of total pressure

No, they are in 1:1 molar ratio. No need for any mass calculations, it is just a direct application of Avogadro's hypothesis.

'Mole fraction of CO2 in aqueous solution is 3.6x10^-5, assuming carbon dioxide in solution is in equilibrium with atmosphere, what is the partial pressure of CO2 in solution? Kh = 1.63x10^3'.

Partial pressure of CO₂ IN solution, or OVER solution?

[offlinedoctor]

Ooh sorry, total pressure for first question, IN solution for second.