Question

Use the data given in the following table to calculate the molar mass of naturally occurring argon isotopes:-

Isotope	Isotopic molar mass	Abundance
36Ar	35.96755 gmol-1	0.337%
38Ar	37.96272 gmol-1	0.063%
40Ar	39.9624 gmol-1	99.600%

Answer 1

Molar mass of argon

`=[(35.96755xx0.337/100)+(37.96272xx0.063/100)+(39.9624xx90.60/100)]" gmol"^-1`

`=[0.121 +0.024+39.802]" gmol"^-1`

= 39.947 gmol^-1