The enthalpy change for chemical reaction is denoted aas `DeltaH^(Theta)` and `DeltaH^(Theta) = H_(P)^(Theta) - H_(R)^(Theta)`. The relation between enthalpy and internal enegry is expressed by equation:
`DeltaH = DeltaU +DeltanRT`
where `DeltaU =` change in internal enegry `Deltan =` change in number of moles, `R =` gas constant.
For a reaction, `2X(s) +2Y(s) rarr 2C(l) +D(g), DeltaH` at `27^(@)C` is `-28 kcal mol^(-1). DeltaU` is .....`kcal mol^(-1)`

Options

A. `-25.5`
B. `+25.5`
C. `-28.6`
D. `28.4`

Explanation

`DeltaH = DeltaU +DeltanRT`
`:. DeltaU = DeltaH - DeltanRT`