Calculate the number of hydrogen atoms in 0.1 mole of H 2 SO 4 .

1 mole of H 2 SO 4 contains (2 × 6.022 × 10 23 ) hydrogen atoms 0.1 mole of H 2 SO 4 contains = = 1.2 × 10 23 atoms of hydrogen

Which of the following contains the maximum number of molecules?
(a) 4 g of O₂
(b) 4 g of NH₃
(c) 4 g of CO₂
(d) 4 g of SO₂