Question

Which of the following compounds has the maximum molar conductivity?

• A. $K\left[Co{\left(N{H}_3\right)}_2{\left(N{O}_2\right)}_4\right]$
• B. $\left[Cr{\left(N{H}_3\right)}_3{\left(N{O}_2\right)}_3\right]$
• C. ${\left[Cr{\left(N{H}_3\right)}_5\left(N{O}_2\right)\right]}_3{\left[Co{\left(N{O}_2\right)}_6\right]}_2$
• D. $Mg\left[Cr\left(N{H}_3\right){\left(N{O}_2\right)}_5\right]$

Answer 1

The correct option is C ${\left[Cr{\left(N{H}_3\right)}_5\left(N{O}_2\right)\right]}_3{\left[Co{\left(N{O}_2\right)}_6\right]}_2$

Molar conductivity can be determined by calculating the number of ions in solution. A solution with higher number of ions will have higher molar conductivity.
1. $K\left[Co{\left(N{H}_3\right)}_2{\left(N{O}_2\right)}_4\right]$ - 2 ions
2. $\left[Cr{\left(N{H}_3\right)}_3{\left(N{O}_2\right)}_3\right]$ - no ionisation
3. ${\left[Cr{\left(N{H}_3\right)}_5\left(N{O}_2\right)\right]}_3{\left[Co{\left(N{O}_2\right)}_6\right]}_2$ - 5 ions
4. $Mg\left[Cr\left(N{H}_3\right){\left(N{O}_2\right)}_5\right]$ - 2 ions

Hence, we can say that ${\left[Cr{\left(N{H}_3\right)}_5\left(N{O}_2\right)\right]}_3{\left[Co{\left(N{O}_2\right)}_6\right]}_2$ will have maximum molar conductivity in solution.