The enthalpy change for chemical reaction is denoted aas `DeltaH^(Theta)` and `DeltaH
Channel: Doubtnut
Date: 2020-07-26

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)`