(Physics)a thermodynamic quantity equivalent to the total heat content of a system. It is equal to the internal energy of the system plus the product of pressure and volume(Symbol: H) (物理)焓,热函(符号:H) ■the change in this quantity associated with a particular chemical process (化学反应的)焓变
语源
1920s: from Greek enthalpein 'warm in', from en- 'within' + thalpein 'to heat'