hopefully someone will be able to help. i just need to know how to get started. here's the problem:

for 1kg of dry air with initial temperature 10C and pressure 1000mb, if its volume expands by 30% during isothermal expansion, calculate the amount of heat that has to be absorbed.... it goes on with several other things to find.

now i don't know if i should find the amount of heat first, or find some other variables first. i've tried it a couple ways but the answers aren't realistic. since this is isothermal, i know that dw=dq, and several other equations. but none of them seem to be of any help without some extra given information. can anyone help me get started with this? thanks