Question

A gas has an initial volume of 168 cm3 at a temperature of 255 K and a pressure of 1.6 atm. The pressure of the gas decreases to 1.3 atm, and the temperature of the gas increases to 285 K.

Answer 1

Would presume you are asked to find the volume, since there is no second volume.

By General Gas Law:

P₁V₁/T₁ = P₂V₂/T₂

1.6 * 168 /255 = 1.3*V₂/285

V₂ = 1.6 * 168 * 285 / (1.3*255)

V₂ = 231.095

Final volume ≈ 231 cm³

Answer 2

Answer: The final volume is  $231cm^3$

Explanation: Using ideal gas equation:

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

$P_1$= initial pressure = 1.6 atm

$V_1$= initial volume = $168cm^3$

$T_1$= initial temperature = 255 K

$P_2$= final pressure= 1.3 atm

$V_2$= final volume = ?

$T_2$= final temperature = 285 K

$\frac{1.6\times 168}{255}=\frac{1.3\times V_2}{285}$

$V_2=231cm^3$