Chemistry - Coordination Chemistry Question with Solution | TestHub

The complex Aquabis(ethane-1,2-diamine)nitrito-O-cobalt(III) ion is $[Co(en{)}_2(H_{2}O)(ONO){]}^{2+}$. As an $M(aa{)}_{2}bc$ type complex, it exists as cis and trans geometrical isomers. The trans isomer is achiral (optically inactive) due to symmetry, while the cis isomer exists as a pair of enantiomers (optically active), totaling three stereoisomers. Since all statements (A, B, C, and D) correctly describe these structural properties, the answer is indeed A, B, C, and D.