It is difficult to overestimate importance of the correct measurement and calculation of various physical data and sizes. Stability of work of large chemical installations and engines sometimes depends on it. Heat of combustion represents amount of the generated heat at combustion of mass or volume unit of substance. The specific heat of combustion pays off as the warmth relation per unit mass (joule on kilogram).
Instruction
1. Take chemical reaction for an example - so you will be able quicker to understand warmth calculation. Try to calculate heat of combustion of acetone - C3H6O + nO2-> 3CO2 + 3N2OOsnovnymi concepts of this area are the highest and the lowest heat of combustion. The highest heat of combustion is defined as the amount of heat which was allocated at full combustion of unit of substance. The lowest is result of subtraction of the highest warmth and warmth of steam formation of water vapor. From it the calculation formula follows: drH = 3dfH(CO2) + 3dfH(H2O) - dfH(C3H6O) - ndfH(O2) where dfH () - warmth of formation of any given substance.dfH (O2) is equal to zero as oxygen represents simple substance. dfH(CO2) = 393.5; 3dfH(H2O) =-241.8; dfH(C3H6O) is warmth of education which needs to be found.
2. Substitute all known components in a formula and you will find what heat of combustion, for example, of acetone which is actively used both in physical, and in chemical industry today is equal to. When conducting various chemical experiments most strictly follow safety regulations which ignoring can lead to awful consequences, up to chemical burns and the disability connected with it.
3. If you need to calculate heat of combustion of fuel, you remember that here it is defined as the amount of heat which was allocated at combustion 1 kg of solid fuel and 1 meter of cubic gaseous fuel. For example, heat of combustion of diesel fuel is equal 42624 kJ/kg, gasoline – 44000, liquefied gas – 45200, kerosene – 43500. Knowledge of all these values allows producers of cars and other equipment using internal combustion engines, it is correct to count the parameters and indicators, vital for stable work. The attention which is paid to the latest chemical developments from producers is connected with it. Not far off those times when invent such type of fuel which will cardinally change the existing automobile market.