1. 1  an implement, such as a hammer, saw, or spade, that is used by hand. 2  a power-driven instrument; machine tool. ( 3 in combination): a toolkit.
The standard enthalpy of combustion is the enthalpy change when one mole of a reactant completely burns in excess oxygen under standard thermodynamic conditions (although experimental values are usually obtained under different conditions and subsequently adjusted).he standard enthalpy of combustion is the enthalpy change when one mole of a reactant completely burns in excess oxygen under standard thermodynamic conditions (although experimental values are usually obtained under different conditions and subsequently adjusted).
The standard enthalpy (heat) of formation for liquid water at 298K (25 o) is -286 kJ mol -1. 2 O (l) , is produced from its elements, hydrogen and oxygen, in their standard states, ie, H 2(g) and O 2(g) . 2 O (g) , is produced from its elements, hydrogen and oxygen, in their standard states, ie, H 2(g) and O 2(g) .