Question

If 35.7 kPa of Bromine gas takes up 41.3 L, how much volume will the gas take up at 13.8 kPa

Answer 1

This follows Boyles law which relates pressure and volume. The law states that pressure is inversely proportional to volume at a constant temperature.
PV = k
where k is a constant.
At two instances ;
P1V1 = P2V2
where parameters for the 1st instance is on the left and parameters for the second instance is on the right. 
37.5 kPa x 41.3 L = 13.8 kPa x V2
V2 = 37.5 x 41.3 / 13.8
V2 = 112.23 L
At the new pressure gas will take up a volume of 112.23 L