Thanks for sharing
I think "volatility" is one of those words that expresses a general concept (liability to evaporate) but is not a precisely defined technical term. For example for an ideal mixture of A and B, the partial pressure of A vapour is xAP°A, where xA is the mole fraction of A in the liquid and P°A is the vapour pressure of pure A. The total vapour pressure of the mixture is given byI am getting a bit confused about this, well I'm sure that if we have the partial pressure of a component doubled (we can also refer to partial pressure by saying vapour pressure of the component in the mixture, because we're talking about a liquid mixture), then we have the double of the particles of that component as the pressure only depends on the number of particles when the solution is ideal. In conclusion, so far I only found out this about volatility:
P = xAP°A + xBP°B
Now I think that saying the volatility of A is twice that of B is ambiguous, because "volatility" is not precisely defined. It could mean
P°A = 2P°B
or it could mean
xAP°A = 2xBP°B
The latter corresponds to your option 2; option 1 is ambiguous - is it referring to vapour pressures of pure A and B, or of A and B in the mixture?