# how many H atoms are in 4.00 moles of H2S?

• Each molecule of H2S has two hydrogen atoms and one sulfur atom. One mole is 6.022e23 molecules. So, 4.00 moles of hydrogen sulfide would have:

(4.00 moles H2S)(2 H atoms/1 H2S)(6.022e23) = 4.82e24 atoms

Source(s): B.BmE, B.S. Biochemistry UMTC
• Easy!

You just have to follow the units. You already have moles. Avogadro’s number is, by definition, 6.022 x10^23^ atoms or molecules per mole. So, you just cancel for moles: (4 moles) (6.022e23 atoms/mol)= 2.4088e24, or 2.41 x 10^24^ molecules of H2S. Multiply this by the number of atoms per molecule: (2 atoms H/molecule H2S)(2.4088e24 molecules)= 4.82e24 atoms of H in 4 moles of H2S.

• Since each molecule of H2S contains two hydrogen atoms, 4.00 moles of H2S contains (2 × 4.00) or 8.00 moles of hydrogen atoms.

Since one mole of hydrogen atoms equals 6.02 × 10^23 atoms, eight moles of hydrogen atoms equals 8.00 × 6.02 × 10^23 atoms or 48.16 × 10^23 hydrogen atoms. Changed to scientific notation this number becomes 4.816 × 10^24 hydrogen atoms or 4.82 × 10^24 hydrogen atoms rounded to three significant figures.

Answer: There are about 4.82 × 10^24 H atoms in 4.00 moles of H2S.

Source(s): personal knowledge