Question

Which of the following shows maximum molar conductance ?

• A. $\left[Co\right(N{H}_3{)}_6]C{l}_3$
• B. $\left[Co\right(N{H}_3{)}_{3}C{l}_3]$
• C. $\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$
• D. $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$

Answer 1

The correct option is A $\left[Co\right(N{H}_3{)}_6]C{l}_3$

Molar conductance depends on the number of ions in aqueous solution. More is the number of ions more is the molar conductance.
(A) $\left[Co\right(N{H}_3{)}_6\left]C{l}_3\stackrel{aq.}{\rightleftharpoons }\right[Co\left(N{H}_3{)}_6{]}^{3+}\right(aq)+3C{l}^{-}(aq)$. It has 4 ions.
(B) $\left[Co\right(N{H}_3{)}_{3}C{l}_3\left]\stackrel{aq.}{\rightleftharpoons }\right[Co\left(N{H}_3{)}_{3}C{l}_3\right]\left(aq\right)\left(\text{neutral}\right)$
There are no ions here.
(C) $\left[Co\right(N{H}_3{)}_{4}C{l}_2\left]Cl\stackrel{aq.}{\rightleftharpoons }\right[Co\left(N{H}_3{)}_{4}C{l}_2{]}^{+}\right(aq)+C{l}^{-}(aq)$. It has 2 ions.
(D) $\left[Co\right(N{H}_3{)}_{5}Cl\left]C{l}_2\stackrel{aq.}{\rightleftharpoons }\right[Co\left(N{H}_3{)}_{5}Cl{]}^{2+}\right(aq)+2C{l}^{-}(aq)$. It has 3 ions.
So, correct answer is A.