Question

How do you determine the average weighted isotopic mass of Carbon?

Answer 1

Well, first you must quote the percentage isotopic masses of the common isotopes.

Explanation:

According to this site, `""^12C` has a 99% abundance, and `""^13C` has a 1% abundance (there are other isotopes, but these are the most abundant). The weighted average is `(12xx0.99)` `+(13xx0.01)` `"amu"` `=` `12.01` `"amu"`.

The `""^13C` isotope is a very important nucleus inasmuch as `""^13C{""^1H}` `"NMR spectroscopy"` can be routinely performed.