Chemical Thermodynamics

Chapter 2

The First Law of Thermodynamics

2.a.  Principle of Conservation of Energy

In 1798 Count Rumford observed that the heat developed during the boring of a cannon was related to the mechanical work involved. J. P. Joule established that when 4.184 joule of work of any kind is converted into heat, 1 calorie of heat is evolved. This relationship is known as the mechanical equivalent of heat. This observation together with the failure to create a machine that can produce one type of energy without the expenditure of an equivalent amount of another type of energy (perpetual motion of the first kind) led to the enunciation of the first law. This is essentially the principle of conservation of energy and can be stated in a number of ways.

‘Although ...