For which of the following chemical equation has `DeltaH=DeltaU-`

Options

A. `C(s)+2H_(2)O(g)to2H_(2)(g)+CO_(2)(g)`
B. `PC l_(5)(g)toPC l_(3)(g)+Cl_(2)(g)`
C. `2CO(g)+O_(2)(g)to2CO_(2)(g)`
D. `H_(2)(g)+Br_(2)(g)to2HB r(g)`.

Answer

D

Explanation

`H_(2)(g)+Br_(2)(g)to2HB r(g)`
We know, `DeltaH=DeltaU+Deltan_(g)RT`
For, `Deltan_(g)=0,DeltaH=DeltaU`
`Deltan_(g)=n_("product (g)")-n_("reactant (g)")`