Question

Which of the following statements corresponds to the nitrogen rule of mass spectrometry?

Select one:

a. Molecules with odd numbers of nitrogens will have an even-numbered molecular weight.

b. Molecules with even numbers of nitrogens will have a molecular ion that is two units less than the molecular weight.

c. Molecules with odd numbers of nitrogens will have an odd-numbered molecular weight.

d. Molecules with even numbers of nitrogens will have a molecular ion that is two units more than the molecular weight

Answer 1

The nitrogen rule important in determining the nitrogen content.Nitrogen rule: If a compound has even number (or 0) of nitrogen atoms, the molecular ion peak will appear at even mass number and if a compound contains odd number of nitrogen atoms then molecular peak will be at odd mass value.

So option C is correct. A is false as odd -even relation is given. B and D does not fit into the rule.