An organic compound A contain 62.0% by mass of carbon, 21.1% by mass of nitrogen, the reminder being hydrogen. Determine the percentage by mass of hydrogen and the empirical formula A.....Can any one help me on that?????

Answer 1

Take a 100 g sample. This will give you
62.0 g C
21.1 g N
100-21.1-62.0 = ?? g O

Now convert each of these grams into moles. moles = g/atomic mass.

The empirical formula consists of small whole numbers for the atoms; therefore, find the ratio of these moles to each other in small whole numbers. The easiest way to do that is to divide the smallest number by itself. That will make the smallest number 1.00. Divide the other values by the same small number. By the way, check the values in your post to make sure there is no typo. Second, is this a book problem or a lab problem?