The following sequence of reactions occurs in the commercial production of aqueous nitric acid: 4 N H 3 ( g ) + 5 O 2 ( g ) ⟶ 4 NO ( g ) + 6 H 2 O ( l ) Δ H = − 800 k J ( 1 ) 2 NO ( g ) + O 2

Question

The following sequence of reactions occurs in the commercial production of aqueous nitric acid:

$4 N H_{3} (g) + 5 O_{2} (g) ⟶ 4 NO (g) + 6 H_{2} O (l) Δ H = - 800 k J (1)$

$2 NO (g) + O_{2} (g) ⟶ 2 N O_{2} (g) Δ H = - 80 k J (2)$

$3 N O_{2} (g) + H_{2} O (l) ⟶ 2 H N O_{3} (a q) + NO (g) Δ H = - 120 k J (3)$

What is the total heat liberated (in kJ/mol) at constant pressure for the production of exactly 1 mole of aqueous nitric acid from $N H_{3}$ by this process?

TestHub · Accepted Answer

Hess's Law: Sum Δ H for reactions adjusted to yield 1 mol HNO₃. Total heat liberated is 420 kJ/mol.

Chemistry - Thermochemistry Question with Solution | TestHub

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