Chapter 12, Problem 12.128SP

Interpretation Introduction

Interpretation:

To find the molecular weight and formula of $\text{β-carotene}$

Concept introduction:
Change in temperature in boiling point is directly proportional to molality

${\text{ΔT}}_{\text{f}}{\text{=K}}_{\text{f}}\text{m}$

Where,

$\begin{array}{l}\Delta T_f=\text{ change in freezing point},{\text{ΔT}}_{\text{f}}\text{=1}{\text{.17}}^{\text{o}}\text{C}\\ {\text{K}}_{\text{f}}=\text{ molal elevation constant of camphor }=\text{37}{\text{.7}}^{\text{o}}{\text{CKgmol}}^{\text{-1}}\\ \text{m}=\text{ molality }\left(\text{moles}/\text{solvent in Kg}\right)\end{array}$

To determine:

The molecular weight and formula of $\text{β-carotene}$

Given:

mass of beta carotene = 0.025 g
mass of solvent = 1.5 g