Question

How many atoms are present in 11.2 litre of chlorine at stp? (a) 6.023 x 1023 (b)6.023 x 1022 (c)6.023 x 1020 (d) 6.023 x 1021?

Answer 1

11.2 litres at STP indicates 0.5 moles of a gas.

1mole of Cl₂ gas at STP contains 2 x Avogadro number of atoms.

So, 0.5moles of Cl₂ gas contains 0.5 x 2 x Avogadro number of Cl atoms

                                                → Avogadro number of Cl atoms

                                                → 6.023 x 10²³ Chlorine atoms