C2H4+H2⟶C2H6
As from the above reaction,
1 mole of ethylene requires 1 mole of hydrogen to react.
Given volume of ethylene =59mL
Given volume of hydrogen =50mL
∴ Only 50mL of ethylene will react.
Pressure (P)=1.5bar=1.48atm
∴W=PΔV=1.48×0.05=0.074Latm=(0.074×101.3)J=7.496J
From first law of thermodynamics-
ΔU=ΔH+W
Given that ΔH for the reaction is −0.31KJ=−310J.
∴ΔU=−310+7.496=302.504J=0.302KJ
Hence the correct answer is 0.302KJ.