Question

A 25.0 L helium balloon was filled in a desert at temperature of 35 ^oC. When the balloon is released to 20,000 ft, the air temperature becomes -48 ^oC. What is the new volume if the atmosphere pressure remains unchanged? Answer in 3 sig-dig number without unit L

Answer 1

$\frac{P_1V_1}{T_1}$ = $\frac{P_2V_2}{T_2}$

Pressure is unchanged

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

$\frac{25.0L}{35⁰C} = \frac{V/2}{-48⁰C}$

V₂ = $\frac{25×(-48)}{35}$ = -34.285 L

V₂ = 34.285 L

3 sig digit

V₂ = 342.85 × 10^-1 L