Chapter 3, Problem 3.36P

Interpretation Introduction

Interpretation:

An excel spreadsheet is to be prepared according to the given structure to calculate the composition of a mixture from the set of obtained peak areas.

Concept introduction:

A device, Gas Chromatograph (GC) is used to separate, identify, and quantify components of gas mixtures. The detector signal is mapped as the series of peaks on a recorder. Each peak corresponds to the specific component and the area under that peak is proportional to the amount of that component in the sample.

$n_i\left(\text{mol}\right)=k_i{A}_i$                  …… (1)

Here, $A_i$ is the area of the peak corresponding to the $i\text{th}$ species and $k_i$ is the proportionality constant.

The formula to calculate mole fraction $\left(x_i\right)$ is:

$x_i=\frac{n_i}{\sum n_i}$                  …… (2)

Here, $n_i$ is the moles of the $i\text{th}$ component and $\sum n_i$ is the total moles of all the components present in the mixture.

The formula to calculate the mass fraction is:

$\text{Mass Fraction}=\frac{n_i{\left(\text{MW}\right)}_i}{\sum n_i{\left(\text{MW}\right)}_i}$                  …… (3)

Here, ${\left(\text{MW}\right)}_i$ is the molecular weight of the $i\text{th}$ component.