What is the percentage occurrence of the isotopes #""^35Cl#, and #""^37Cl# is the average atomic mass of chlorine is #35.45*"amu"#?

1 Answer
Feb 11, 2017

Answer:

The weighted average of the isotopes is #35.45*"amu....."#

Explanation:

And thus #x_1xx35*"amu"+x_2xx37*"amu"=35.45*"amu"#.

This is one equation in 2 unknowns. However, we can supply another equation because WE ASSUME that there are only the two isotopes of #Cl#, #""^35Cl# and #""^37Cl#, and thus #x_2=1-x_1#.

And thus we get the equation:

#x_1xx35+(1-x_1)xx37=35.45#

So #37-2x_1=35.45#

And #x_1=(37-35.45)/2=0.775#

And #x_2=0.225#.

And thus #%# #""^35Cl=77.5%#, and #%# #""^37Cl=22.5%#.

Capisce?