At `25^(@)C` if the standard enthalpies of formation of MX(s), `M^(+)(aq)` and `X^(-)(aq)` are -x, y and -z `kJ*mol^(-1)` respectively, then what will the heat of reaction be for the reaction `M^(+)(aq)+X^(-)(aq)toMX(s)`.

Explanation

`M^(+)(aq)+X^(-)(aq)toMX(s)`
The standard heat of reaction,
`DeltaH^(0)=DeltaH_(f)^(0)[MX(s)]-DeltaH_(f)^(0)[M^(+)(aq)]-DeltaH_(f)^(0)[X^(-)(aq)]`
`=(-x-y+z)kJ*mol^(-1)`.