What is the empirical formula of monosodium glutamate (MSG) which contains 35.50% C, 4.77% H, 8.29% N, 13.6% Na, and 37.90% O?

Question

An empirical formula shows the smallest whole-number ratio of different atoms in a chemical substance. However, the simplest ratio does not always indicate the actual ratio in the chemical substance. Molecular formulas specify the actual number of atoms of each element in one molecule or formula unit of the chemical substance. The molecular formula is a whole-number multiple of the empirical formula.

Answer 1

Assume 100 g of the compound, then % is the same as grams

Moles C = 35.50 g C x 1 mol C /12 g = 2.96 moles C

Moles H = 4.77 g H x 1 mol H / 1 g = 4.77 moles H

Moles N = 8.29 g N x 1 mol N / 14 g = 0.592 moles N

Moles Na = 13.6 g Na x 1 mol Na / 23 g = 0.591 moles Na

Moles O = 37.9 g O x 1 mol O / 16 g = 2.37 moles O

Divide all by 0.591 to get whole numbers:

5 moles C

8 moles H

1 mol N

1 mol Na

4 mol O

Empirica formula = C₅H₈NO₄Na