Question

What is the molecular mass of glucose molecule $\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$?

Answer 1

Step1. Molecular Mass

• Molecular mass is the sum of atomic mass, measured in amu.
• The mass of one carbon atom is equal to the atomic mass unit (formerly abbreviated as 'amu,' but now spelled as 'u' – unified mass) according to the latest IUPAC recommendation.

Step2. Formula for molecular mass of glucose molecule $\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$

• The molecular mass of ${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$=$\text{6×The atomic mass of C+12×}\mathrm{The}\mathrm{atomic}\mathrm{mass}\mathrm{of}\text{H+6×Atomic mass of O}$

Step3. Calculation of molecular mass of glucose molecule

The molecular mass of glucose$\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$= $\left(\text{6×12.01+ 12×1.0079+6×16}\right)\text{u}$

=$\left(72.06+12.0948+96\right)\text{u}$

=$180.1548\text{u}$

$\simeq 180\text{u}$

Hence, the molecular mass of glucose molecule is $180\text{u}$.