question_answer 19)

 How many geometric isomers are possible in the following coordination entity : (i) [Cr(C2O4)3 ]3– (ii) [Co(NH3)3Cl3]

Answer:

Ans.       (i) [Cr(C2O4)3]3-. No geometrical isomerism is shown. (ii) Two isomers are possible for [Co(NH3)3Cl3]  Note. 1, 2, 3,-position is called cis isomer while position 1, 2, 6 is called as trans isomer. In cis-form, similar groups occupy the corners of one of the octahedral faces and hence is called facial or face-isomer. On the other hand, in trans-form the positions are around the meridian of the octahedron, hence is called meridional (mer) isomer.