Question

224cm3 of ammonia undergoes catalytic oxidation in the presence of Pt to give nitric oxide and water vapour. Calculate the volume of oxygen required for the reaction. All volumes measured at room temperature and pressure.

Answer 1

Answer ⇒ 280 cm³ of the Oxygen required. 

Explanation ⇒

Reaction of the Ammonia with the Oxygen in the Presence of the Platinum is 

4NH₃ + 5O₂ ----------→ 4NO + 6H₂O

From this Reaction, 
4 vol. of the Ammonia requires 5 vol. of the Oxygen. 
∴ 1 vol.------------------------------5/4 vol. of the Oxygen.
∴ 224 cm³--------------------------5/4 × 224 cm³ of the Oxygen. 
= 5 × 56  = 280 cm³ of the Oxygen. 



Hence, the volume of the Oxygen is required is 280 cm³. 


Hope it helps.

Answer 2

4NH3 + 5O2 -----pt ---- 4NO + 6H2O

WHEN THE AMOUNT OF AMMONIA IS 224 cm3 THEN LET AMOUNT OF OXYGEN BE X.

4 VOLUMES OF AMMONIA + 5 VOLUMES OF OXYGEN ---------- 4 VOLUMES OF NITRIC OXIDE + 6 H2O

4 VOLUMES OF AMMONIA = 224

1 VOLUME OF AMMONIA = 224/4 = 56

THEREFORE,

5 VOLUMES OF OXYGEN = 56*5 280cm3

THE VOLUME OF OXYGEN IS 280 cm3.