Tag: coordination chemistry

Questions Related to coordination chemistry

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

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

  1. $1$

  2. $2$

  3. $3$

  4. $6$

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Correct Option: B

The secondary valency of Chromium in $[Cr(en) _3]CI _3$ is

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

  1. 6

  2. 3

  3. 2

  4. 4

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Correct Option: A

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

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

  1. only one type of valency

  2. two types of valencies

  3. three types of valencies

  4. four types of valencies

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Correct Option: B
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 $B$

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

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

  1. $SrSO _2$

  2. $MgSO _2$

  3. $CaSO _4$

  4. None

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Correct Option: B

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

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

  1. same as primary valency

  2. sum of primary and secondary valences

  3. same as secondary valency

  4. none of the above

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Correct Option: C
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.

How many of the following metals when heated in an atmosphere of N2 gas form nitrides ?
Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba

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

  1. 9

  2. 5

  3. 3

  4. 6

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Correct Option: B

1 mole of co-ordinate compound $CoCl _3$ on reaction with excess AgNCl $143.5$gms of AgCl ppt . Then number of chloride ions satisfying both primary valency and secondary valency are?

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

  1. $2$

  2. $3$

  3. $1$

  4. $0$

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Correct Option: A
Explanation:

Moles of $AgCl$ formed $=\cfrac{143.5}{143.5}=1$

$1$ mole of $CoCl _3$ gives $1$ mol of $AgCl$ ppt.
Secondary valence is the number of ions that are coordinated to metal ion. Here, $1Cl^-$ ion is not coordinated to the metal ion, due to which it gives $AgCl$ ppt. Hence, no. of chloride ions satisfying the given condition $=2.$

According to Werner's theory the primary valency and secondary valency in complex $[Co(NH _3) _4Cl _2]Cl$ is respectively:

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

  1. 3,3

  2. 3, 6

  3. 6, 3

  4. 4, 2

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Correct Option: B
Explanation:

The primary valency is the oxidation state of the metal ion and the coordination number of the metal is the secondary valency of the metal ion. 


The oxidation number of $Co = x + 0 -3 = 0$

                                           $x = 3$

The primary valency is 3 and the secondary valency is 6. Therefore, the correct option is B.

Which of the following is not correctly matched ? 

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

  1. $[Fe (CN) _6]^{3-} d^2 sp^3$, paramagnetic

  2. $[Ni (CO) _4] -sp^3$, diamagnetic

  3. $[Fe(en) _3]^{+3} - sp^3 d^2$, paramagnetic

  4. $[FeCl _2 (H _2O) _2] sp^3$, paramagnetic

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Correct Option: A

According to Werner's theory state which of the following statements are correct:


1. Ligands are connected to the metal ions by covalent bonds
2. Secondary valencies have directional properties
3. Secondary valencies are non-ionisable.

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

  1. 1, 2, and 3 are correct

  2. 2 and 3 are correct

  3. 1 and 2 are correct

  4. 1 ,2 are correct,and 3 is not correct

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Correct Option: A