Answer:
Kc → 5.58×10⁻⁴
Explanation:
Equilibrium reaction is:
2NOCl (g) ⇄ 2NO (g) + Cl₂(g)
Initially we have 1.25 moles of NOCl
After the equilibrium, we have 1.10 moles. So, during the process:
(1.25 mol - 1.1 mol) = 0.15 moles have reacted.
As ratio are 2:2, and 2:1, 0.15 moles of NO and (0.15 /2) = 0.075 moles of chlorine, were produced in the equilibrium.
Finally in equilibrium we have: 1.10 moles of NOCl, 0.15 moles of NO and 0.075 moles of Cl₂. But these amount are not molar, so we need molar concentration in order to determine Kc:
1.10 mol /2.50L = 0.44 M
0.15 mol / /2.50L = 0.06 M
0.075 mol /2.50L = 0.03 M
Let's make expression for Kc → [Cl₂] . [NO]² / [NOCl]²
Kc = (0.03 . 0.06²) / 0.44² → 5.58×10⁻⁴