What is the empirical formula? A compound being used in experimental medicine is 78.14% boron (B) and 21.86% hydrogen (H). The empirical formula of the compound will have a boron to hydrogen ratio of :

The empirical formula is BH₃. Its B:H ratio is 1:3.

Assume that you have 100 g of the compound.

Then you have 78.14 g B and 21.86 g H.

Now, we must convert these masses to moles and find their ratios.

From here on, I like to summarize the calculations in a table.

Element Mass/g Moles Ratio Integers

B 78.14 7.2285 1 1

H 21.86 21.686 3.0001 3

The empirical formula is BH₃.