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 idea here is that the standard molar enthalpy of combustion, Î´Hâcomb, tells you the enthalpy change associated with the combustion of one mole of a given substance under standard conditions. This tells you that every mole of methane that undergoes combustion under standard conditions gives off 890.8 kJ of heat. All you have to do here is use the molar mass of methane to see how many moles you have in that 50.00 g sample. 50.00gâ1 mole CH416.0425g=3.1167 moles CH4.