Lowering of Vapour Pressure - a C.P ?

[zorro]

Is lowering of vapour pressure a colligative property?

I tried proving this and found it to be true.

P_a = P^o_aχ_a, where a=solvent and b=solute

Substituting χ_a=1-χ_b and some rearranging, we get

P^o_a-P_a=P^o_aχ_b

As P^o_a is constant for a given liquid at a given temperature, lowering of vapour pressure (LHS) is directly proportional to the no. of moles of solute provided the solution is very dilute.

Is my proof correct?

 

[wazani]

Hi
your proof is correct
right lowering of vapour pressure really is a colligative property

 

[zorro]

But my book says that Relative lowering of vapour pressure is a colligative property but lowering of vapour pressure is not a colligative property.

 

[asamaid1]

hi,

can anyone tell me where i can get a free reaction simulation software, like aspen plus.

thanks.