question_answer

Arrange the following in order of increasing molar conductivity:

I. \[K[Co{{(N{{H}_{3}})}_{2}}{{(N{{O}_{2}})}_{4}}]\]

II. \[[Cr{{(N{{H}_{3}})}_{3}}{{(N{{O}_{2}})}_{3}}]\]

III. \[{{[Cr{{(N{{H}_{3}})}_{5}}(N{{O}_{2}})]}_{3}}\,{{[Co{{(N{{O}_{2}})}_{6}}]}_{2}}\]

IV. \[Mg[Co(N{{H}_{3}})\,{{(N{{O}_{2}})}_{5}}]\]

A) \[II<I<III<IV\] 

B)               \[II<I<IV<III\]

C)  \[III<IV<II<I\]  

D)                \[IV<III<I<II\]

Correct Answer: B

Solution :

[b]

(I)

II, \[[Cr{{(N{{H}_{3}})}_{3}}{{(N{{O}_{2}})}_{3}}]\]being non-electrolyte, does not ionise.

III.

IV.

Greater the number of ions and greater the total (positive or negative) charge produced after ionisation, greater is the value of molar conductivity. Hence, increasing order of molar conductivity is \[II<I<IV<III\]