# A helium balloon with an internal pressure of 1.00 atm and a volume of 4.50 L at 20.0°C is released. What volume will the balloon occupy at an altitude where the pressure is 0.600 atm and the temperature is -20.0° C?

Dec 26, 2016

6.47 L

#### Explanation:

We can use the Ideal gas equation PV = nRT .....(a)

${p}_{1}$ ${v}_{1}$ / ${T}_{1}$ = ${p}_{2}$ ${v}_{2}$ / ${T}_{2}$

${p}_{1}$ = 1 atm, ${v}_{1}$ = 4.50 L , ${T}_{1}$ = 293 K

${p}_{2}$ = 0.6 atm, ${v}_{2}$ = ? , ${T}_{2}$ = 253 K

Plugging in the values;

(1 atm x 4.50 L ) / 293 K = 0.6 atm x ${v}_{2}$ / 253 K

(4.50 atm L x 253 K ) / ( 0.6 atm x 293 K) = ${v}_{2}$

${v}_{2}$ = 1138.5 atm L K / 175.8 atm K

${v}_{2}$ = 6.47 L approx