Question

For the complex $ML_2$, stepwise formation constants for
$M + L \rightleftharpoons ML$
$ML + L \rightleftharpoons ML _{2} $
are 4 and $3 .$ Hence, overall stability constant for
$M +2 L \rightleftharpoons ML _{2} $ is:

• A. 12
• B. 7
• C. 1.33
• D. 0.75

Answer 1

Answer: (A)

$M + L \rightleftharpoons ML , \quad K _{1}=\frac{[ ML ]}{[ M ][ L ]}=4$

$ML + L \rightleftharpoons ML _{2}, \quad K _{2}=\frac{\left[ ML _{2}\right]}{[ ML ][ L ]}=3$

$M +2 L \rightleftharpoons ML _{2}, \quad K _{3}=\frac{\left[ ML _{2}\right]}{[ M ][ L ]^{2}}$

$K _{3}= K _{1} K _{2}=12$