1. The problem statement, all variables and given/known data A house has a volume of 770 m^3. (a) what is the total mas of air inside the house at 20 Celsius? (b) If the temperature drops to -10 Celsius, what mass of air enters or leaves te house? 2. Relevant equations PV = nRT 3. The attempt at a solution I found the solution for part a which I think 924 kg. I found this answer by multiplying 770 m^3 by 1.2 kg (density of air at 20 Celsius: 1.2kg/m^3). But I do not know how to find the answer to part b. I read the whole chapter but still did not know how. Please help me.