Chemistry
posted by Beth .
For one mole the ideal gas law is pV=RT , write down the exact differential dV.
Would I be right to differentiate with respect to T and p separately?...
V = RT/p
dV = R/p  (RT)/(p^2)

I think they mean
dV = (R/p) dT  (RT)/(p^2) dp
This satisfies the requirement that the partial derivative of (R/p) with respect to p equals the partial derivative of (RT)/(p^2) with respect to T.
See
http://mathworld.wolfram.com/ExactDifferential.html
for more about exact differentials