Question

If a sample of this compound contains 6.4×1022 sodium ions, how many sulfide ions does it contain?

Answer 1

The ionic compound formed by sodium and sulfur is Na2S, whose name is sodium sulfide.


The chemical formula tells you the ratio between the two elements is 2Na/1S or 1S/2Na

So, if you have 6.4 * 10^22 sodium ions, you will have

6.4 * 10^22 Na * 1S / 2Na = 3.2 * 10^22 S.


Answer: the compound contains 3.2 * 10^22 sulfide ions.