=8‌ moles ‌ ‌2H2O⟶2H2+O2 ‌2‌ moles water ‌⟶3‌ moles of gases ‌ ‌8‌ moles water ‌⟶12‌ moles of gases ‌ ‌‌ Volume of gases ‌=‌
12×R×300
P
m3 ‌‌ Work done ‌=−P‌ext ‌∆V ‌=−P‌ext ‌×[‌
12×8.3×300
P
−0] ‌=−29880J ‌=−29.88‌kJ ‌‌ Ans. ‌29.88