Question

150g of a gas at 10.0°C and 1.0 atm pressure occupies 913L volume. The volume of the gas increases to 988L and its temperature increases to 41.5°C while the pressure remains constant. Calculate ΔE, q and w for the gas. (Specific heat of the gas = 5.2J/g°C and 1L.atm = 101.3J).

Answer 1

$W=\int PdV=P\triangle V (\because P$ is constant$)$ $=1\times (988-913)\times 101.3 \ J=$ $7597\times 10^{-3} KJ=7.6KJ$

$Q=$ $mC_P\triangle T=150\times 5.2J/g\degree C\times(41.5-10)=$ $24.57\ KJ\approx24.6\ KJ$

$\triangle E=Q+W$ (As work is done by the gas)$=7.6+24.6=32.2\ KJ$