Question

What is Law of Definite or Constant Proportions (Proust, 1799)?

Answer

Law of Definite or Constant Proportions is that the same compound always contains the same proportions by weight. Thus, if the elements A and B combine together to form the compound AB, then in whatever manner AB is formed, it is always composed of these two elements only. Also, if AB is formed in more than one way, the proportion of two elements in all the samples by weight will be same.