A helium weather balloon is filled to a volume of 219 m³ on the ground, where the pressure is 754 torr and the temperature is 25 °C. As the balloon rises, the pressure and temperature decrease, so it is important to know how much the gas will expand to ensure that the balloon can withstand the expansion. What is the volume at an altitude of 10,000 m, where the atmospheric pressure is 210 torr and the temperature is -43 °C?

Strategy

Verify that the units are appropriate (temperature must be in kelvins), and use the combined gas law to solve for the final volume.