Calculate the atomic mass (average) of chlorine using the following data:
% Natural Abundance Molar Mass
\(^{35}\text{Cl}\) 75.77 34.9689
\(^{37}\text{Cl}\) 24.23 36.9659
% Natural Abundance Molar Mass
\(^{35}\text{Cl}\) 75.77 34.9689
\(^{37}\text{Cl}\) 24.23 36.9659
Solution and Explanation
The average atomic mass of chlorine
= [(Fractional abundance of \(^{35}\text{Cl}\))(Molar mass of \(^{35}\text{Cl}\)) + (Fractional abundance of \(^{35}\text{Cl}\))(Molar mass of \(^{35}\text{Cl}\))]
\(= \bigg[{(\frac{75.77 }{ 100})(34.9689 u)} + {(\frac{24.23 }{ 100})(36.9659 u)}\bigg]\)
= 26.4959 + 8.9568
= 35.4527 u
∴ The average atomic mass of chlorine = 35.4527 u
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Concepts Used:
Molecular Mass of Polymers
It is described as the distribution rather than a specific number due to the occurrence of polymerization in such a way as to produce different chain lengths. Polymer MW is derived as follows:
\[M_{W} = \sum^{N}_{i=1} w_{i}MW_{i}.\]Where,
wi = the weight fraction of polymer chains having a molecular weight of MWi.
The MW is typically measured by light dispersing experiments. The degree of dispersing arises from the molecule size and, thus, molecular weight dispensation can be mathematically set on the total scattering created by the sample.