Question

write the formula for calculating number of molecules?

Answer 1

Multiply Moles by the Avogadro Constant. Multiply the number of moles by the Avogadro constant, 6.022 x 10^23, to calculate the number of molecules in your sample.

In benzene c6h6 the no. Of molecules is 1, atoms is 12. Now if they ask you to calculate the number of atoms in 1gm benzene, then equate the quantities with an unknown and compare with Avogadro's number. You will get number of atoms in 1 gm. Now since we have equal molecules of H and C, we can straightway divide the no of atoms obtained in one gram by 12 and get number​of benzene molecules. Then just half that number to get number of carbon and hydrogen atoms. Carbon is monoatomic so carbon molecules is =C atoms. For h2 it is just half.

Answer 2

6.022 * 10²³*n Is the answer