Question

$\Delta g^{\circ }(HI,g)\cong +1.7kJ.$ What is the equilibrium constant at $25^{\circ }C$ for $2HI(g)\rightleftharpoons H_{2(g)}+I_2(g)$? ’

• A. $24.0$
• B. $3.9$
• C. $2.0$
• D. $0.5$

Answer 1

Answer: (D)

$\Delta G^o=-2.303\times 8.314\times 10^{-3}\times 298$ log $K_p$
$1.7=-2.303\times 8.314\times 10^{-3}\times 298\times$ log $K_p$
$K_p=0.5$