Question

Which of the following compounds show optical isomerism?
(i) $cis-[Co(N{H}_3{)}_{4}C{l}_2{]}^{+}$
(ii) $trans-[Co(en{)}_{2}C{l}_2{]}^{+}$
(iii) $cis-[Co(en{)}_{2}C{l}_2{]}^{+}$
(iv) $[Co(en{)}_3{]}^{3+}$
Choose the correct answer codes given below

• A. i and ii
• B. ii and iii
• C. iii and iv
• D. i, iii and iv
• E. i, ii, iii and iv

Answer 1

Answer: (C)

The compounds, and cis $-{\left[Co(en{)}_{2}C{l}_2\right]}^{+}$and ${\left[Co(en{)}_3\right]}^{3+}$ show optical isomerism as they do not possess any element of symmetry. The trans- ${\left[Co(en{)}_{2}C{l}_2\right]}^{+}$exists in optically inactive meso form. cis $-{\left[Co{\left(N{H}_3\right)}_{4}C{l}_2\right]}^{+}$is also optically inactive as it contains plane of symmetry.