The enthalpy of formation of water is –285.8 kj/mol. what can be inferred from this statement?

From the given statement it can be inferred that the heat is released during the process.  

Explanation:

The enthalpy of formation of water is mentioned as -285.8 kJ/mol, this indicates that the reaction is exothermic, that is, the enthalpy of formation is negative.  

The exothermic reaction signifies that the heat is discharged at the time of the reaction process. The heat is discharged from reaction to the surroundings is articulated with a negative sign showing that the energy is given out in the reaction process. In the given statement, the formation of water occurs by giving out heat, that is, -285.8 kJ/mol.