Urea is manufactured on large scale by passing CO 2 (g) through ammonia solution followed by crystallization. CO 2 for the above reaction is prepared by combustion of hydrocarbons. If combustion of 236.1 kg of a saturated hydrocarbon produces as much CO 2 as required for production of 1000 kg of urea, deduce the number of carbon atoms in the hydrocarbon.

Step-by-step solution

Urea manufacture CO 2 + 2 NH 3 ⟶ H 2 NCO NH 2 + H 2 O 44 g 60 g For 1000 Kg urea CO 2 required is 4 4 6 0 × 1 0 0 0 × 1 0 3 = 7 3 3 . 3 3 g × 1 0 3 C n H 2 n + 2 + 3 n + 1 2 O 2 → n CO 2 + n + 1 H 2 O ℓ n = 7 3 3 . 3 3 4 4 × 1 0 3 moles Apply POAC to C n 2 3 6 . 1 × 1 0 3 1 2 n + 2 n + 2 = 7 3 3 . 3 3 4 4 × 1 0 3 × 1 n 1 4 n + 2 × 2 3 6 . 1 = 1 6 . 6 7 236.1 n = 233.38 n + 33.34 2.72 n = 33.34 n = 3 3 . 3 4 2 . 7 2 ≅ 1 2