Question

Equivalent amounts of H₂ and I₂ are heated in a closed vessel till equilibrium is obtained. If 80% of the hydrogen can be converted to HI, the \( K_c \) at this temperature is

• A. 64
• B. 16
• C. 0.25
• D. 0.5

Hint:

To calculate \( K_c \), use the equilibrium concentrations of reactants and products and apply the equilibrium constant expression.

Answer 1

The Correct Option is A

Step 1: Understanding the equilibrium.
The reaction is: \[ H_2(g) + I_2(g) \rightleftharpoons 2HI(g) \] If 80% of hydrogen reacts, this gives us the concentration of reactants and products, which can be used to calculate \( K_c \).

Step 2: Conclusion.
Thus, the correct value of \( K_c \) is 64. Hence, the correct answer is option (A).

Final Answer: \[ \boxed{\text{(A) 64}} \]