The Total solution for NCERT class 6-12
ΔUθof combustion of methaneis – X kJ mol–1. The value of ΔHθ is
(i) = ΔUθ
(ii) > ΔUθ
(iii) < ΔUθ
(iv)= 0
Since ΔHθ = ΔUθ + ΔngRT and ΔUθ = –X kJmol–1,
ΔHθ = (–X) + ΔngRT.
⇒ ΔHθ < ΔUθ
Therefore,alternative (iii) is correct.