Question

Calculate the molecular weight of the following:

Potassium dichromate(${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$)

Answer 1

Definition of molecular weight

Molecular weight, also called molecular mass, is the mass of a molecule of a substance, based on 12 as the atomic weight of carbon-12. It is calculated in practice by summing the atomic weights of the atoms making up the substance's molecular formula.

Calculation

Given, $\mathrm{K}=39,\mathrm{Cr}=52,\mathrm{O}=16$

The molecular weight of Potassium dichromate = $2\times 39+2\times 52+7\times 16=294amu$

$\therefore$The molecular weight ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ is 294 amu.