NEET Practice Questions (MCQs) with Answers & Solutions

(b) (I) IUPAC name is Pentaamminenitrito-N-chromium(III) tetrachlorozincate(II)

     (II) It does not exhibit geometrical isomerism

     (III) It shows linkage isomerism due to presence of ambidentate ligand ${\mathrm{NO}}_2^{-}$

      (IV) Its coordination isomers are :

                                           $\left[\mathrm{CrCl}\right({\mathrm{NH}}_3{)}_5\left]\right[{\mathrm{ZnCl}}_3\left({\mathrm{NO}}_2\right)]$

                                           $\left[{\mathrm{Crcl}}_2\right({\mathrm{NH}}_3{)}_4\left]\right[{\mathrm{ZnCl}}_2\left({\mathrm{NO}}_2\right){\mathrm{NH}}_3]$

                                           $\left[\mathrm{Zn}\right({\mathrm{NO}}_2\left)\right({\mathrm{NH}}_3{)}_3\left]\right[{\mathrm{CrCl}}_4\left({\mathrm{NH}}_3{)}_2\right]$

(b) CO bond strength is reciprocal to the extent of back donation involved in synergic bonding i.e. $\mathrm{M}\rightleftharpoons \mathrm{CO}$

(d) CO is called $\mathrm{\pi }$-acid ligand. In metal carbonyls complexes, there is donation of an electron pair from carbon to the empty orbital of metal and then simultaneously a back $\mathrm{\pi }$-bonding is formed by sideways overlap of a filled orbital on the metal with empty antibonding ${\mathrm{\pi }}_{2\mathrm{py}}^{*}$ orbital of CO

The complex ions [Fe(H2O)6]2+ and [Fe(CN)6]4- differ in their color and magnetic moment. [Fe(H2O)6]2+ has a pale green color and is paramagnetic due to unpaired electrons, while [Fe(CN)6]4- is diamagnetic and has an intense yellow color due to the strong ligand field provided by the CN- ligands.

(d) 

$$\begin{gathered} \mathrm{NI}(\mathrm{CO}{)}_4; {\mathrm{\mu }}_{\mathrm{eff}}=0 \\ [\mathrm{Co}\left({\mathrm{NH}}_3\right){}_4({\mathrm{NO}}_2{)}_2{]}^{+};{\mathrm{\mu }}_{\mathrm{eff}}=0 \\ \left[\mathrm{Ag}\right(\mathrm{CN}{)}_2];{\mathrm{\mu }}_{\mathrm{eff}}=1.732 \mathrm{BM} \end{gathered}$$

(b) $\left[{\mathrm{CrCl}}_2\right(\mathrm{OH}{)}_2\left({\mathrm{NH}}_3{)}_2\right]$ show cis and trans isomerism, cis isomer is optically active.

(b) No. of geometrical isomers 

$\left[\mathrm{Pt}\right({\mathrm{NO}}_2\left)\right({\mathrm{NH}}_3\left)\right({\mathrm{NH}}_2\mathrm{OH}\left)\right(\mathrm{Py}){]}^{+ }$= 3 and No. of stereoisomers for

$\left[\mathrm{Pt}\right(\mathrm{Br}\left)\right(\mathrm{Cl}\left)\right(\mathrm{I}\left)\right({\mathrm{NO}}_2\left)\right({\mathrm{NH}}_3\left)\right(\mathrm{Py}\left)\right]$ = 15+15

${\mathrm{H}}_2\left[{\mathrm{PtCl}}_6\right]$ is an acid, not salt hence its name : hexachloroplatinic (IV) acid

whenever HYDROGEN is present as cation , it is called as acid rather than salt.

ie 

KNO2 is known as POT nitrite

but HNO2 is not known as HYDROGEN NITRITE, its known as  NITROUS ACID.

(d) Due to absence of vacant atomic orbital as well as ${\mathrm{\pi }}^{*}$ molecular orbital ${\mathrm{O}}_2^{2-}$ does not as $\mathrm{\pi }$ acid ligand .