Question

A compound is made by mixing cobalt(III) nitrite and potassium nitrite solutions in the ratio of $1: 3 .$ The aqueous solution of the compound showed $ 4$ particles per molecule whereas molar conductivity reveals the presence of six electrical charges. The formula of the compound is :

• A. $Co \left( NO _{2}\right)_{3}.2 KNO _{2}$
• B. $Co \left( NO _{2}\right)_{3} .3 KNO _{2}$
• C. $K _{3}\left[ Co \left( NO _{2}\right)_{6}\right]$
• D. $K \left[ Co \left( NO _{2}\right)_{4}\right]$

Answer 1

Answer: (C)

$Co \left( NO _{2}\right)_{3} +\underset{\text{potassium cobalt nitrite}}{3KNO _{2} \rightarrow K _{3}\left[ Co \left( NO _{2}\right)_{6}\right]}$