Question

a 20 liter sample of gas is kept under a constant pressure of 100 kpa. the temperature is lowered from 360 k to 90 k. what is the new volume

Answer 1

To solve this we assume that the gas inside the balloon is an ideal gas. Then, we can use the ideal gas equation which is expressed as PV = nRT. At a constant pressure and number of moles of the gas the ratio T/V is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

T1 / V1 = T2 / V2

V2 = T2 x V1 / T1

V2 =90 x 20 / 360

V2 = 5 L