Question

a weather balloon contains 450 L of helium at 25 degrees celcuis what is the volume of the balloon when it ascends to an altitude where the temperature is 2 degrees celcuis and the pressure is 650 mmHg

Answer 1

Because we are looking for the volume change caused by a temperature change at constant pressure, this is Charles’s law.

$\frac{V_1}{T_1}=\frac{V_2}{T_2}$

We have to convert temperature from degrees celsius to kelvin.

25 degrees celsius = 25 + 273 = 298 K

2 degrees celsius = 2 + 273 = 275 K

V2 = (V1/T1) x T2

V2 = (450 L/298 K) x 275

V2 = 415.3 L