Question

$28.0\, L$ of $CO _2$ is produced on complete combustion of $168 \, L$ gaseous mixture of ethene and methane at $25^{\circ} C$ and $1 \, atm$ Heat evolved during the combustion process is ______$kJ$ Given : $\Delta H _{ c }\left( CH _4\right)=-900 \, kJ\, mol ^{-1}$ $\Delta H _{ c }\left( C _2 H _4\right)=-1400\, kJ \, mol ^{-1}$

Answer 1

The correct answer is 925.

⇒28=16.8+x
x=11.2L
nCH4​​=RTPV​=0.082×2981×5.6​=0.229 mole
nC2​H2​​=0.082×29811.2​=0.458 mole
∴ Heat evolved =0.229×900+0.458×1400
=206.1+641.2
=847.3kJ