A 101.96 g sample of a solid is broken down into 53.96 g of aluminum and an unknown amount of oxygen. If a chemist wants to make 1,937 grams of that solid without any leftovers, how much aluminum
and oxygen should she react together?

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.