Chapter 14, Problem 14.1P

(a)

Interpretation Introduction

Interpretation:

The average molar mass is to be calculated by using measurement of mass spectrometry.

Concept introduction:

Osmometry gives the number average molar mass and formula is,

$\begin{array}{l}{\stackrel{-}{\text{M}}}_{\text{n}}=\frac{N_1{M}_1+N_2{M}_2}{N_1+N_2}\\ {\stackrel{-}{\text{M}}}_{\text{n}}=\frac{\left(\frac{m_1}{M_1}\right)M_1+\left(\frac{m_2}{M_2}\right)M_2}{\left(\frac{m_1}{M_1}\right)+\left(\frac{m_2}{M_2}\right)}\\ {\stackrel{-}{\text{M}}}_{\text{n}}=\frac{m_1+m_2}{\left(\frac{m_1}{M_1}\right)+\left(\frac{m_2}{M_2}\right)}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The average molar mass is to be calculated by using light scattering.

Concept introduction:

Light scattering gives the number average molar mass and the formula is,

${\stackrel{-}{\text{M}}}_w=\frac{m_1{M}_1+m_2{M}_2}{m_1+m_2}$