For this case, we use the equation for an ideal gas which is expressed as PV=nRT where P is the pressure, V is the volume, n is the number of moles and T is the temperature. We calculate as follows:
PV = nRT T = PV / nR T = 20 kPa (100 L) / 1 mol (8.314) T = 240.56 K
A calorie is the amount of energy needed to raise the temperature of one gram of water 1 degree centigrade. If we are raising 835 grams of water 30 degrees then we multiply 835*30 to get 25,050 calories.
