Question

Which of the following has least conductivity in aqueous solution?

• A. $CO(N{H}_3{)}_{4}C{l}_3$
• B. $Co(N{H}_3{)}_{3}C{l}_3$
• C. $Co(N{H}_3{)}_{5}C{l}_3$
• D. $Co(N{H}_3{)}_{6}C{l}_3$

Answer 1

The correct option is A $CO(N{H}_3{)}_{4}C{l}_3$

Conductivity $\alpha$ no. of ions dissociated in solution.

$Co{\left({NH}_3\right)}_4{Cl}_3\to {\left[Co{\left({NH}_3\right)}_4{Cl}_2\right]}^{+}+{Cl}^{(-)}$

2 ions

$Co\left({NH}_3\right){Cl}_3\to \left[Co\left({NH}_3\right){\left(Cl\right)}_3\right]$

1 ion

$Co{\left({NH}_3\right)}_5{Cl}_3\to {\left[Co{\left({NH}_3\right)}_{5}Cl\right]}^{2+}+2{Cl}^{(-)}$

3 ions

$Co{\left({NH}_3\right)}_6{Cl}_3\to {\left[Co{\left({NH}_3\right)}_6\right]}^{3+}+3{Cl}^{(-)}$

4 ions

$\therefore Co{\left({NH}_3\right)}_6{Cl}_3$ has highest conductivity.