According to Charles's Law, for a given mass of an ideal gas at constant pressure, the volume is directly proportional to its absolute temperature assuming in a closed system. Mathematical equation is : V1/T1=V2/T2. 87 degrees Celsius equals 87+273.15=360.15 k, and standard temperature is 273.15 k. So, 180/360.15 = V2/273.15, V2=180*273.15/360.15 = 136.52 mL, which is the volume of gas at standard temperature.
