Chapter 24

Explain the important distinction between each of the following pairs: (a) coordination number and oxidation number; (b) monodentate and polydentate ligands; (c) cis and trans isomers; (d) dextrorotatory and levorotatory compounds; (e) low-spin and highspin complexes.

The oxidation state of $\mathrm{Ni}$ in the complex ion ${[\mathrm{Ni}(\mathrm{CN}{)}_4\mathrm{I}]}^{3-}$ is $(\mathrm{a})-3;(\mathrm{b})-2;(\mathrm{c})0;(\mathrm{d})+2;(\mathrm{e})+3$.

The coordination number of $\mathrm{Pt}$ in the complex ion ${[{\mathrm{PtCl}}_2(\mathrm{en}{)}_2]}^{2+}$ is $(\mathrm{a})2;(\mathrm{b})3;(\mathrm{c})4;(\mathrm{d})5;(\mathrm{e})6$.

Of the following complex ions, the one that exhibits isomerism is (a) ${\left[\mathrm{Ag}{\left({\mathrm{NH}}_3\right)}_2\right]}^{+};$ (b) ${\left[{\mathrm{CoNO}}_2{\left({\mathrm{NH}}_3\right)}_5\right]}^{2+};$ $(\mathrm{c}){[\mathrm{Pt}(\mathrm{en}){\left({\mathrm{NH}}_3\right)}_2]}^{2+};$ (d) ${\left[\mathrm{CoCl}{\left({\mathrm{NH}}_3\right)}_5\right]}^{2+};$ (e) ${\left[{\mathrm{PtCl}}_6\right]}^{2-}$.

Of the following complex ions, the one that is optically active is (a) $\mathrm{cis}-{[{\mathrm{CoCl}}_2(\text{ en }{)}_2]}^{+};$ (b) ${\left[{\mathrm{CoCl}}_2{\left({\mathrm{NH}}_3\right)}_4\right]}^{+}$ (c) ${\left[{\mathrm{CoCl}}_4{\left({\mathrm{NH}}_3\right)}_2\right]}^{-};(\mathrm{d}){\left[{\mathrm{CuCl}}_4\right]}^{-}$.

The number of unpaired electrons in the complex ion ${\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]}^{2+}$ is (a) $5;(\mathrm{b})4;(\mathrm{c})3;(\mathrm{d})2;(\mathrm{e})1$.

Of the following, the one that is a Bronsted-Lowry acid is (a) ${\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{2+};$ (b) ${\left[{\mathrm{FeCl}}_4\right]}^{-};$ (c) ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$ (d) ${[\mathrm{Zn}(\mathrm{OH}{)}_4]}^{-}$.

The most soluble of the following solids in ${\mathrm{NH}}_3(\mathrm{aq})$ is (a) $\mathrm{Ca}(\mathrm{OH}{)}_2;$ (b) $\mathrm{Cu}(\mathrm{OH}{)}_2;$ (c) ${\mathrm{BaSO}}_4;$ (d) ${\mathrm{MgCO}}_3$ (e) $\overline{{\mathrm{Fe}}_2{\mathrm{O}}_3}$.

Name the following coordination compounds. Which one(s) exhibit(s) isomerism? Explain. (a) $\left[\mathrm{CoBr}{\left({\mathrm{NH}}_3\right)}_5\right]{\mathrm{SO}}_4$ (b) $\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right][\mathrm{Co}(\mathrm{CN}{)}_6]$ (c) ${\mathrm{Na}}_3\left[\mathrm{Co}{\left({\mathrm{NO}}_2\right)}_6\right]$ (d) $[\mathrm{Co}(\mathrm{en}{)}_3]{\mathrm{Cl}}_3$

Write appropriate formulas for the following species. (a) dicyanoargentate(I) ion (b) triamminenitrito-N-platinum(II) ion (c) aquachlorobis(ethylenediamine)cobalt(III) ion (d) potassium hexacyanochromate(II)