Question

Which of the following contains maximum number of molecules :
(i) 36 g water
(ii) 28 g carbon monoxide

Answer 1

(i) Molar mass of water (H₂O) is 18 g/mol 18 g of water contains 1 mole which contains 6.023 × 10²³ molecules of it.
Therefore, 36 g water will contain 2 moles i.e, 6.023 × 10²³ × 2 molecules
= 12.046 × 10²³ molecules
(ii) Molar mass of carbon monoxide (CO) is 28 g/mol So, 28 g of CO will contain 1 mole i.e, 6.023 × 10²³  molecules
Therefore 36 g of water will contain maximum number of molecules.