Can someone explain to me why the energy value given standard enthalpy of combustion is always negative?
Thankyou
2007-03-11 01:21:43 · 5 answers · asked by howdy 2 in Science & Mathematics ➔ Chemistry
Negative values of enthalpy mean that heat is given off.
A positive value of enthalpy means that it gets colder as it reacts, so it isn't really combustion.
The point of combustion is to get hot, so reactions with negative enthalpies are the onlyones that will work.
2007-03-11 01:31:17 · answer #1 · answered by tgypoi 5 · 1⤊ 1⤋
OKK the enthalpy for any general reaction is always negative..... only and only if heat is given out that is the reaction is exothermic so in combustion heat is given out watsoever be the case .... because combustion is an exothermic reaction always
2007-03-11 01:55:57 · answer #2 · answered by Smart Gal 2 · 1⤊ 0⤋
as the heat is given out during combustion the enthalpy of combustion is negative
2015-11-12 13:22:48 · answer #3 · answered by neelakantha 1 · 1⤊ 0⤋
Combustion is an exothermic reaction which have negative delta H .
2007-03-11 05:51:10 · answer #4 · answered by Anonymous · 1⤊ 0⤋
In simple terms, the energy that was stored in the compound has been taken away and expelled as heat, light and sound.
2007-03-11 06:24:27 · answer #5 · answered by Tim Owen 1 · 1⤊ 1⤋