Question

Of the following complex ions. The one that probably has the largest overall formation constant $K _{ f }$ is :-

• A. $\left[ Co \left( NH _{3}\right)_{6}\right]^{3+}$
• B. $\left[ Co \left( H _{2} O \right)_{6}\right]^{3+}$
• C. $\left[ Co \left( NH _{3}\right)_{2}\left( H _{2} O \right)_{4}\right]^{3+}$
• D. $\left[ Co ( en )_{3}\right]^{3+}$

Answer 1

Answer: (D)

order of $K _{ f }=4>1>2>3$
$\left[ Co ( en )_{3}\right]^{3+}$ has highest value of $K _{ f }$ among complex due to chelation