Answer to Question #97353 in General Chemistry for stanley Eze

Question

Nitrogen has an atomic mass of 14.0067, its naturally occuring isotopes are 14N (14.003) and 15N (15.001). What are the relative abundance of each isotope?

Answer 1

Nitrogen has an atomic mass of 14.0067 u.

Let one of its isotope having atomic mass 14.003 u has natural abundance of x %.

Other isotope having atomic mass 15.001 u has natural abundance of (100-x) %.

$(x×14.003 + (100-x)× 15.001)/100 =14.0067$

$14.003x +1500.1 -15.001x = 1400.67$

$0.998x=99.43$

$x = 99.43/0.998$

$x = 99.629$

$100-x =0.371$

Relative abundance of isotope having atomic mass 14.003 is 99.629 %(Ans)

The other isotope has abundance of 0.371 %(ans)