In order to decompose 9 g of water, 142.5 kJ of heat is required. Hence enthalpy formation of water is _____

In order to decompose 9 g of water, 142.5 kJ of heat is required. Henc

1.	In order to decompose 9 g of water, 142.5 kJ of heat is required. Hence enthalpy formation of water is _____
Answer» Solution :`UNDERSET"18 (g)"(H_2O) to H_2 + 1//2O_2` 9g `H_2O` is decomposed by -142.5 KJ amount of heat . `therefore` 18 g of `H_2O` will be decomposed by `142.5/cancel9 xxcancel18^(2)`=+285 kJ `therefore` 18 g of `H_2O` is formed by -285 kJ amount of heat (EVOLUTION of heat =- ve sign)