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Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

Among the following complexes (K-P) :
$K _3[Fe(CN _6]-K  $ and $  [Co(NH _3) _6]Cl _3-L$ ; 
$Na _3[Co(oxalate) _3]-M $ and    $  [Ni(H _2O) _6]Cl _2-N$ ;
$K _2[Pt(CN) _4]-O$ and $[Zn(H _2O) _6](NO _3) _2 - P$;
the diamagnetic complexes are:

  1. K,L,M,N

  2. K,M,O,P

  3. L,M,O,P

  4. all

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$K _3[Fe(CN _6]-K  $ = $ 3d^5$ it is paramagnetic 


 $  [Co(NH _3) _6]Cl _3-L$ = $3d^6$ is diamagnetic

$Na _3[Co(oxalate) _3]-M $ = $3d^6$ is diamagnetic 

 $  [Ni(H _2O) _6]Cl _2-N$ = $3d^8$ is paramagnetic

$K _2[Pt(CN) _4]-O$ = $d^3 $ it is diamagnetic

 and $[Zn(H _2O) _6](NO _3) _2 - P$;= $ d^6$ it is diamagnetic

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

According to Werner's coordination theory, there are _______ kinds of valency, _______ and ___. The primary valency of a central metal ion is satisfied with _____.

  1. three, negative, positive, cations

  2. different, negative, positive, anions

  3. two, primary, secondary, anions

  4. two, saturated, unsaturated, cations
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to Werner's coordination theory, there are two kinds of valency, primary and secondary. The primary valency of a central metal ion is satisfied with anions.
For example, in $[Cu(NH _3) _4]SO _4$ primary valency is 2 and secondary valency is 4.
Secondary valence refers to coordination number. Since copper is coordinated to 4 ammonia ligands, secondary valence is 4. Primary valence is satisfied by anions. Since sulphate ion has $-2$ charge, primary valence is 2.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

Which of the following sets of examples and geometry of the compounds is not correct?

  1. Octahedral - $[Co(NH _3) _6]^{3+}, [Fe(CN) _6]^{3-}$
  2. Square planar - $[Ni(CN) _4]^{2-}, [Cu(NH _3) _4]^{2+}$
  3. Tetrahedral- $[Ni(CO) _4], [ZnCl _4]^{2-}$
  4. Trigonal bipyramidal - $[Fe(NH _3) _6]^{2+}, [CuCl _4]^{2-}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$[Fe(NH _3) _6]^{2+}=Fe^{2+}=[Ar]3d^6=$ Octahedral.

Hybridisation is $=sp^3d^2$ .

$[CuCl _4]^{2+}=Cu^{2+}=[Cu]3d^{9}=$ Tetrahedral.
Hybridisation $=$ $sp^3$

These two do not have trigonal bipyramidal geometry.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

Which of the following complexes will have a tetrahedral shape?

  1. $[PdCl _4]^{2-}$
  2. $[Pd(CN) _4]^{2-}$
  3. $[Ni(CN) _4]^{2-}$
  4. $[NiCl _4]^{2-}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$[NiCl _4]^{2-}=$ $Cl^-\rightarrow $ Weak field ligand.

$\Rightarrow Ni^{2+}\Rightarrow [Ar]3d^8$
As the ligands is weak field ligands the complex has tetrahedral geometry of $sp^3$ hybridisation.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

The two isomers X and Y with the formula $Cr(H _2O) _5ClBr _2$ were taken for experiment on depression in freezing point. It was found that one mole of X gave depression corresponding to $2$ moles of particles and one mole of Y gave depression due to $3$ moles of particles. The structural formulae of X and Y respectively are:

  1. $[Cr(H _2O) _5Cl]Br _2$; $[Cr(H _2O) _4Br _2]Cl\cdot H _2O$
  2. $[Cr(H _2O) _5Cl)]Br _2$; $[Cr(H _2O) _3ClBr]\cdot 2H _2O$
  3. $[Cr(H _2O) _5Br]BrCl$; $[Cr(H _2O) _4ClBr]Br\cdot H _2O$
  4. $[Cr(H _2O) _4Br _2]Cl\cdot H _2O$; $[Cr(H _2O) _5Cl]Br _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Cr(H _2O) _5ClBr _2\longrightarrow$ 2 moles of particle.

It compoubnd is $[Cr(H _2O) _4(Br _2)]Cl.H _2O$
It gives $[Cr(H _2O) _4Br _2]^{+},C\bar l\Rightarrow $ Two particles.
So, $X=[Cr(H _2O) _4Br _2]Cl.H _2O$
If $Y=[Cr(H _2O) _5Cl]Br _2$
It gives $[Cr(H _2O) _5Cl^{2+},2B\bar r\Rightarrow $ 3 particles.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

Number of chlorides satisfying secondary valency in $CoCl _{3},\ 4NH _{3}$

  1. $1$
  2. $2$
  3. $3$
  4. $6$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In CoCl3 * 4NH3, the coordination compound is [Co(NH3)4Cl2]Cl. The secondary valency (coordination number) is 6, satisfied by 4 NH3 and 2 Cl ions. The remaining Cl ion is outside the coordination sphere.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

According to Werner’s theory of valency transition metals possesses:

  1. only one type of valency

  2. two types of valencies

  3. three types of valencies

  4. four types of valencies
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to Werner’s theory of valence, transition metals has two valencies are primary valencies and secondary valency.
Primary valencies are those which are statisfied by ligands through coordination bonds and charge that remained on the coordination sphere is satisfied by secondary valence.


Hence, the correct option is $B$

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy ?

  1. $SrSO _2$
  2. $MgSO _2$
  3. $CaSO _4$

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hydration enthalpy decreases down the group for alkaline earth metal sulphates. Magnesium sulphate (MgSO4) has a relatively small cation size, making its hydration enthalpy high enough to overcome its lattice enthalpy, resulting in high solubility.

Multiple choice chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

The co-ordination number of a metal in co-ordination compound is:

  1. same as primary valency

  2. sum of primary and secondary valences

  3. same as secondary valency

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The secondary valency is equal to the coordination number the secondary valency are non ionizable valencies. These are satisfied by neutral molecules or negative ions.  For example in $[Ni(CO) _4]$ the coordination number of Ni metal is four and its secondary valency is also four.