Multiple choice Which of the following occupies 22.4 litres at N.T.P.? 17 gm NH3 22 gm CO2 1.7 gm NH3 4.4 gm CO2 Reveal answer Fill a bubble to check yourself A Correct answer Explanation At N.T.P., one mole of any gas occupies 22.4 litres. The molar mass of NH3 is 14 + 3 = 17 grams. Therefore, 17 grams of NH3 is one mole and occupies 22.4 litres.