Very simple npm package, just give it a valid chemical formula and get its molar mass.

Install with: npm i molarcalc

Then include this in your code:

const molarcalc = require('molarcalc');

console.log(molarcalc.calc('NaCl'));

Response should be: { atoms: [ 'Na', 'Cl' ], mass: '58.4425' }

molarcalc.calc() function returns a JSON object with an array of all the atoms found in the formula, and the calculated molar mass.

It recognises:

• Elements (written as their periodic table symbols).
• Frequent o-chem abbreviations such as 'Me' for methyl or 'Ph' for 'phenyl' (will probably add some more in the future).
• Numbers.
• Parentheses surrounding several elements. It will read everything inside and add it to the calculation a number of times indicated by the number after the closing parenthesis. Just a complicated way of saying that it knows how to read parentheses.

It does NOT recognise:

• Words. Won't recognise 'tri-' or 'acetyl'.
• 'Ac' for 'acetyl', as it creates a conflict with element Actinium. You will need to write 'CH3CO', 'C2H3O', 'COMe', etc.