Talk:Standard enthalpy change of combustion
Do the fuels you are burning have to be in their gasesous state?
No they do not, and please sign your name with four tildes (~) after you edit a discussion page. 220.127.116.11 10:38, 25 June 2007 (UTC)
No mention is made of the fact that there are two heats of combustion for a particular substance being burned from its particular phase. They are referred to, in my industry, as higher and lower heats of combustion. They differ due to more than one circumstance, but the main one is that they differ by the heat of vaporization (or condensation, really) of the produced water, if any. This can be considerable. 18.104.22.168 (talk) 19:00, 23 July 2011 (UTC)Kenneth E. Kogut