Per NCERT eqn 5.10, the relationship between ΔH and ΔU for a gaseous reaction is which?
AΔH = ΔU − Δn_g RT
BΔH = ΔU + Δn_g RT — where Δn_g = (moles of gaseous products) − (moles of gaseous reactants)
CΔH = nRT only
DΔH = ΔU × Δn_g
Answer & Solution
Correct answer: B. ΔH = ΔU + Δn_g RT — where Δn_g = (moles of gaseous products) − (moles of gaseous reactants)
Per NCERT eqn 5.10, ΔH = ΔU + Δn_g RT. Significant only for gas reactions. For solids/liquids, ΔH ≈ ΔU.
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