Question

Write the formulae for Ethanol and calculate the molecular mass for Ethanol

Answer 1

• The formula of Ethanol is ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$
• Molecular mass of a substance is defined as the sum of masses of atoms or elements present in the molecule.
• So the atomic mass of ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$- Atomic mass of $\mathrm{C}$$\times 2$+Atomic mass of ${\mathrm{H}}_{}$$\times 6$+Atomic mass of $\mathrm{O}$

$$\begin{gathered} =12\times 2+1\times 6\times 16 \\ =46u \end{gathered}$$