Explain standard enthalpy of reaction.

Explanation

Standard enthalpy of reaction is the change in enthalpy that occurs, when the number of moles of the reactants indicated by the balanced chamical equation have completely reached under standard conditions, that is, 298 K and one bar pressure `[Delta H^(@)]`
Example : `H_(2(g)) + (1)/(2)O_(2(g)) rarr H_(2)O_((l)) , Delta H^(@) = -285.8 kJ`.