Question

At a given temperature the pressure of a gas reduces by 75% of its initial value and the volume increases by 40% of initial value find the temperature if the initial temperature was -10°C

Answer 1

[3.15degree C] Is the initial value

Answer 2

Answer: $1.33\times 10^{-3}K$

Explanation: The combined gas equation is,

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

where,

$P_1$ = initial pressure of gas = p

$P_2$ = final pressure of gas = $p-0.75p=0.25p$

$V_1$ = initial volume of gas = v

$V_2$ = final volume of gas =$v+0.40v=1.40v$

$T_1$ = initial temperature of gas = $-10^oC=-10+273=263K$

$T_2$ = final temperature of gas = ?K

$\frac{p\times v}{263}=\frac{0.25p\times 1.40v}{T_2}$

$T_2=1.33\times 10^{-3}K$