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Chemistry · EQUILIBRIUM
हिन्दीFor the equilibrium \( \text{H}_2(\text{g}) + \text{I}_2(\text{g}) \rightleftharpoons 2\text{HI}(\text{g}) \), the value of \( K_c \) is \( 49.0 \) at a certain temperature. If \( 1.0\text{ mol} \) of \( \text{H}_2 \) and \( 1.0\text{ mol} \) of \( \text{I}_2 \) are placed in a \( 2.0\text{ L} \) flask and allowed to reach equilibrium, what is the total number of moles of \( \text{HI} \) present at equilibrium?
Correct answer · Option 4
1.56 mol
Explanation
Let moles reacted be \( x \). At equilibrium, moles of \( \text{H}_2 = 1 - x \), \( \text{I}_2 = 1 - x \), \( \text{HI} = 2x \). \( K_c = \frac{(2x)^2}{(1-x)^2} = 49 \implies \frac{2x}{1-x} = 7 \implies 2x = 7 - 7x \implies 9x = 7 \implies x = 7/9 \approx 0.778\text{ mol} \). Moles of \( \text{HI} = 2x = 2 \times 0.778 = 1.556 \approx 1.56\text{ mol} \).
