A salt containing water of crystallization gave the following percentage composition :
Mg = 9.76 ; S = 13.01 ; O = 26.01 and H2O = 51.22. Calculate the simplest formula (At mass of Mg = 24)
We discussed in the article – Hill nomenclature – A guide to writing empirical and molecular formula, the correct position to place the water of crystallization while writing the empirical formula, that is, at the end.
There are four steps to finding an unknown compound's empirical formula, which are discussed in this article.
The problem is solved using those steps, and their results are compiled in one table as shown below-

The empirical formula of the compound is MgSO4.7H2O.
Related reading -
Molecular Formula (subscribers only premium article)
Empirical Formula (subscribers only premium article)
How to calculate Empirical Formula from percentage composition and atomic masses (subscribers only premium article)
Difference between empirical and molecular formula (free)
Hill nomenclature (free)
