Phosphoric acid ($H_ {3} PO_ {3} $), its molar mass is related to stoichiometry and is the basis for research.

Phosphorus has an atomic weight of about 31 dollars $. The atomic weight of hydrogen is nearly 1 dollar $, and the atomic weight of oxygen is about 16 dollars $.

In phosphoric acid ($H_ {3} PO_ {3} $), there are hydrogen atoms three, phosphorus atoms one, and oxygen atoms three.

Its molar mass is calculated by summing the product of the atomic weight and the number of atoms. The contribution of hydrogen atoms is 3 dollars\ times1 = 3 $, the contribution of phosphorus atoms is 31 dollars\ times1 = 31 $, and the contribution of oxygen atoms is 3 dollars\ times16 = 48 $.

The molar mass of phosphite is 3 dollars + 31 + 48 = 82g/mol $. This value is crucial for chemical operations and experimental considerations. It helps to accurately grasp the amount of reaction and clarify the composition ratio of substances. It is an important parameter for chemical study and practice.