Given a molecular equation string determine its atomic weight.
Limited atoms of C H O N and S where wts are rounded to [12 1 16 14 32].
Example molecules and wts:
CH4 16; CH3OH 32; O2 32; C6H6 78; H2SO4 98; radical SO4 96;
Input: Molecular Eqn [string with no spaces, all Caps]
Output: Molecular Wt [approx wt]
Saw this as a question on Matlab Answers.