Ammonia is oxidised: 4NH3 + 5O2 -> 4NO + 6H2O. 3.4 g of NH3 (17 g/mol) is mixed with 6.4 g of O2 (32 g/mol) and the reaction goes to completion. The mass of water formed and the mass of NH3 left are respectively

JEE Advanced levelSingle correct optionDifficulty 3 of 3mc067

Ammonia is oxidised: $4 NH X_{3} + 5 O X_{2} 4 NO + 6 H X_{2} O$ . $3.4 g$ of $NH X_{3}$ ( $17 g/mol$ ) is mixed with $6.4 g$ of $O X_{2}$ ( $32 g/mol$ ) and the reaction goes to completion. The mass of water formed and the mass of $NH X_{3}$ left are respectively

NH X_{3}

= 0.2 mol,

O X_{2}

= 0.2 mol.

NH X_{3}

would need 0.25 mol

O X_{2}

, so

O X_{2}

limits.

H X_{2} O

= 0.2 x 6/5 = 0.24 mol = 4.32 g;

NH X_{3}

used = 0.2 x 4/5 = 0.16 mol, left = 0.04 mol = 0.68 g.