Chelation

Q.

What is a Ramchandran plot?

Q.

What is meant by the chelate effect? Give an example.

Q.

Amongst the following, the most stable complex is

(i) [Fe(H₂O)₆]³⁺

(ii) [Fe(NH₃)₆]³⁺

(iii) [Fe(C₂O₄)₃]^3-

(iv) [FeCl₆]^3-

Q.

Identify the correct statements for the behavoiur of ethane-1, 2-diamine as a ligand.

(a) It is a neutral ligand
(b) It is a didentate ligand
(c) It is a chelating ligand
(d) It is a unidentate ligand

Q. Which of the following statement is (are) correct
A. The coordination number of each type of ion in CsCl crystal is 8
B. A metal that crystallizes in bcc structure has a coordination number of 12
C. A unit cell of an ionic crystal shares some of its ions with other unit cells
D. The length of the unit cell in NaCl is 552 pm $(r_{N{a}^{+}}=95pm;r_{C{l}^{-}}=181pm)$

1. B, C
2. A, C, D
3. C, D
4. Only D

Q.

Is CN A Bidentate Ligand?

Q.

Barium ions, $C{N}^{-}$ and $C{o}^{+2}$ form an ionic complex. If this complex is 75% ionized in aqueous solution with Vant Hoff factor(i) equal to four and paramagnetic moment is found to be 1.73 BM(due to spin only) then hybridization state of Co(II) in the complex will be

1. $s{p}^3{d}^2$

2. $ds{p}^3$

3. $s{p}^{3}d$

4. $d^{2}s{p}^3$

Q. Incorrect order of stability is:

1. ${\left[Co\right(ox{)}_3]}^{3-}>{\left[Co\right(H_{2}O{)}_6]}^{3+}$
2. ${\left[Pt{F}_6\right]}^{2-}>{\left[Ni{F}_6\right]}^{2-}$
3. ${\left[\text{Ni(trien)}\right]}^{2+}>{\left[Ni\right(en{)}_2]}^{2+}$
4. ${\left[Ni\right(N{H}_3{)}_6]}^{2+}>\left[{\text{Ni(dmg)}}_2\right]$

Q. H3PO4+NaOH its equation is

Q.

The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?
(a) $\left[Fe\right(CO{)}_5]$
(b) $\left[Fe\right(CN{)}_6{]}^{3-}$
(c) $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$
(d) $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$

Q.

A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent?
(a) Thiosulphato
(b) Oxalato
(c) Glycinato
(d) Ethane-1, 2-diamine

Q.

What is meant by the chelate effect? Give an example.

Q. Which of the following ligands form a chelate

1. Acetate
2. Oxalate
3. Cyanide
4. Ammonia

Q. What do you understand by the term 'autoprotolysis of water’? What is its significance?

Q. What is mechanism of reduction of crotonaldehyde with lialh4

Q. The basic unit present in pyrosilicates is

1. 
2. 
3. 
4. 

Q. $\left[Co\right(en{)}_3{]}^{3+}$ ion is expected to show :

1. Two optically active isomers ; d and $l$ forms.
2. Three optically active isomers ; d, $l$ and meso forms.
3. Four optically active isomers ; cis- d and $l$ isomers and trans- d and $l$ isomers.
4. None of these

Q. What are chelates? Giving one example and write the importance of chelate?

Q.

Is cyanide a chelating ligand?

1. True
2. False

Q.

Classify the following amines as primary, secondary or tertiary:

(i)

(ii)

(iii) (C₂H₅)₂CHNH₂

(iv) (C₂H₅)₂NH

Q. Which among the following is a $\pi$ acceptor ligand? ___

Q. Consider the following statements.
(a) Mixture of $CO$ and $N_2$ is called synthesis gas.
(b) $CO$ reduces both $F{e}_2{O}_3$ and $ZnO$ to their respective metals.
(c) $CO$ is a $\pi$ acid ligand.
The correct statements are:

1. (a) and (b) only
2. (b) and (c) only
3. (a) and (c) only
4. (a), (b) and (c)

Q. In an aqueous solution of $NiC{l}_2$ , if the bidentate ligand ethylene - 1, 2 - diamine (en) is added progressively in molar ratios such as Ni ∶ en - 1 ∶ 1, 1 ∶ 2, 1 ∶ 3 then three octahedron complexes x, y and z are formed respectively. Select the correct statement(s) about x, y and z.

1. Complex x has the maximum value of absorbed wavelength
2. Complex y is coloured
3. Complex z has the maximum number of chelate rings
4. All three are paramagnetic outer orbital complexes

Q.

A chelating agent possesses :

1. two or more electron pair for co-ordination
2. polydentate nature
3. formation of strain free ring with central atom
4. monodentate nature

Q. The coloration of $\left[Fe\right(acac{)}_3\left]\text{and}\right[Fe(phen{)}_3{]}^{3+}$ respectively are due to

1. ligand to metal charge transfer, metal to ligand charge transfer
2. metal to ligand charge transfer, metal to ligand charge transfer
3. metal to ligand charge transfer, d-d transition
4. d-d transition, intravalence charge transfer

Q.

In the following questions a statement of assertion (A) followed by a statement of reason (R) is given. Choose the correct answer out of the following choices.
(a) Assertion and reason both are true, reason is correct explanation of assertion.
(b) Assertion and reason both are true but reason is not the correct explanation of assertion.
(c) Assertion is true, reason is false.
(d) Assertion is false, reason is true.

Assertion (A) Toxic metal ions are removed by the chelating ligands.
Reason (R) Chelate complexes tend to be more stable.

Q.

What is lead poisoning?

Q. Among the following the most stable complex is

1. $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$
2. $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$
3. $\left[Fe\right(CN{)}_6{]}^{3-}$
4. $[FeC{l}_6{]}^{3-}$

Q.

The most stable ion is:

1. $\left[Fe\right(C_2{O}_4{)}_3{]}^{3-}$

2. $\left[Fe\right(Cl{)}_6{]}^{3-}$

3. $\left[Fe\right(SCN{)}_6{]}^{3-}$

4. $\left[Fe\right(H_{2}O{)}_6{]}^{3+}$

Q. An example of chelating ligand is:

1. $N{O}_2^{-}$
2. Chloro
3. Bromo
4. en