An equilibrium system for the reaction between hydrogen and iodine to give hydrogen iodide at `670` K in a `5` litre flask contains `0.4` mole of hydrogen , `0.4` mole of iodine and `2.0` moles of hydrogen iodide. Calculate equilibrium constant.

Explanation

To calculate the equilibrium constant (Kc) for the reaction between hydrogen (H₂) and iodine (I₂) to form hydrogen iodide (HI) at 670 K in a 5-liter flask, we can follow these steps:

### Step 1: Write the balanced chemical equation
The balanced chemical equation for the reaction is:
\[ \text{H}_2(g) + \text{I}_2(g) \rightleftharpoons 2 \text{HI}(g) \]

### Step 2: Determine the number of moles of each substance at equilibrium
From the problem, we know the following:
...