Chemistry MCQs for NEET — Practice Questions with Answers

(d) $\left[\mathrm{CoBr}\right({\mathrm{NH}}_3{)}_5]{\mathrm{SO}}_4 \rightleftharpoons [\mathrm{CoBr}({\mathrm{NH}}_3{)}_5{]}^{2+}+{\mathrm{SO}}_4^{2-}$ ;        Total charges = 4 

$\left[\mathrm{Co}\right({\mathrm{SO}}_4\left)\right({\mathrm{NH}}_3{)}_5]\mathrm{Br} \rightleftharpoons [\mathrm{Co}\left({\mathrm{SO}}_4\right)({\mathrm{NH}}_3{)}_5{]}^{+} + {\mathrm{Br}}^{-}$ ;      Total Charges = 2

hence, both have different molar conductivities.

(d) Complexes $\left[\mathrm{Co}\right({\mathrm{SO}}_4\left)\right({\mathrm{NH}}_3{)}_5]\mathrm{Br} \mathrm{and} [\mathrm{Co}\left({\mathrm{SO}}_4\right)\left({\mathrm{NH}}_3{)}_5\right]\mathrm{Cl}$  are not any isomers to each other.

(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