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The law is named after the scientist Joule; who also gave the conversion from Joule to Calorie; which is the more usual unit for heat. According to that,
1 Caloric = 4.2 Joule. The number "4.2" is commonly denoted by a symbol J and is called the "mechanical equivalent of heat"."
૧૦૫. અગ્નિની ક્રિયામાં વાયુ રૂપ ઇંધણની રાસાયણિક ક્રિયાને સમજવા માટે અમુક વ્યાખ્યાઓ આ રીતે પ્રસ્તુત છે, જેનાથી અગ્નિના રાસાયણિક રૂપના કોરા ભૌતિક પરિણમનથી ભિન્નત્વ સ્પષ્ટ થાય છે. જુઓ :
"Theory and Mechanism of Combustion
The combustion of a gaseous substance is the combination of oxygen with the combustible gas. The intermediate stages through which the gas passes from its initial condition to the final product of combustion are termed as mechanism of reaction.
Usually, a combustible gas consists of carbon monoxide, hydrogen and hydrocarbons. The mechanism of combustion reactions of these elements will be considered separately.
Carbon Monoxide
It is a well known fact that in presence of water vapours, carbon monoxide burns quickly and intensively. In absolute absence of water vapours the combustion of carbon monoxide almost ceases. This phenomenon can be explained as follows at the first instance the water vapours are endowed with the high electrical conductivity which helps to increase the process of ionisation: secondly, steam molecules colliding with those of carbon dioxide (CO2) obstruct radiation of heat by carbon dioxide molecules, which are formed during the combustion. In absolute absence of water vapours, there would be a considerable loss of heat due to radiation and thus the combustion would proceed slowly.
Hydrogen
It has been finally established that hydrogen burns first in preference to carbon. According to Dixon, a struggle arises between the carbon and hydrogen for combination with the oxygen.
Hydrocarbons
There are two hypotheses regarding the combustion of hydrocarbons: hydroxylation and peroxidation.
The essence of mechanism of hydroxylation, according to Bone, is that there is an initial association of oxygen with the hydrocarbon molecule, forming intermediate "Hydroxylated" compounds, which in turn burn or are broken down thermally.
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