Molecular Weight Formula

The weight in atomic mass units of each of the atoms in a given formula is the molecular weight of a substance. An atomic mass unit is described as 1/12^th the weight of the carbon-12 isotope. The old symbol was amu, while the most correct symbol is u (a lower-case letter u).

The molecular weight of a material is required to tell an individual how many grams there in one mole of that chemical substance. The mole is the typical method in chemistry for interacting as to how much of a substance is present.

SOLVED EXAMPLES

Problem 1: 

Find out the molecular weight of Fe₂O₃?

Answer:

Fe₂O₃ contains two atoms of iron and three atoms of oxygen

Mass of Iron = 55.847 amu

Mass of Oxygen = 15.9994 amu

Molecular weight of Fe₂O₃ is

Fe₂O₃ = 2 × 55.847  + 3 × 15.9994 

Fe₂O₃ = 159.692 amu