State law of reciprocal proportion with an example.

The law of reciprocal proportion, also known as Richter's law, is a principle in chemistry that states that when elements combine to form compounds, the ratio of their masses is either the same or a simple multiple of the ratio in which they combine with one another. In simpler terms, it refers to the relationship between the masses of two elements that react with a fixed mass of another element to form compounds.

Mathematically, if two elements (A and B) combine with a fixed mass of another element (C) to form two different compounds, then the mass of element A divided by the mass of element B will be a simple whole number or a ratio of small whole numbers.

Example:

Let's consider the reaction between hydrogen (H) and oxygen (O) to form water (H2O) and hydrogen peroxide (H2O2).

Formation of Water (H2O):
When 2 grams of hydrogen (H) reacts with 16 grams of oxygen (O), it forms 18 grams of water (H2O).
Mass of H: 2 grams
Mass of O: 16 grams
Mass ratio H:O = 2:16 = 1:8

Formation of Hydrogen Peroxide (H2O2):
When 2 grams of hydrogen (H) reacts with 32 grams of oxygen (O), it forms 34 grams of hydrogen peroxide (H2O2).
Mass of H: 2 grams
Mass of O: 32 grams
Mass ratio H:O = 2:32 = 1:16

Now, if we take the mass ratio of hydrogen to oxygen in water and divide it by the mass ratio of hydrogen to oxygen in hydrogen peroxide:

(H2O mass ratio) / (H2O2 mass ratio) = (1:8) / (1:16) = 2

The result is a simple whole number (2). This demonstrates the law of reciprocal proportion, as the mass ratio of hydrogen to oxygen in water is exactly twice the mass ratio of hydrogen to oxygen in hydrogen peroxide.

This law helps chemists establish consistent patterns and ratios in chemical reactions, leading to the development of stoichiometry and a better understanding of the relationships between elements in compounds.