Question Set D

CBSE 12th Standard Chemistry Coordination Compounds HOT Questions Study Material - QB365

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Questions:

Generic 2

5 x 2 = 10

Explain what is meant by the following:
(i) Peptide linkage
(ii) Pyronose structure of glucose

Identify the compounds A, B, C and D in the following sequence of reaction:

Which of the following compounds will have the highest melting point and why?

Name the metal present in
(i) Chlorophyll
(ii) Haemoglobin
(iii) Vitamin B₁₂
(iv) cis-platin.

Why is CO a stromger lig and than CI^-?

Generic 3

5 x 3 = 15

(i) Which one of the following is a disaccharide: Starch, Maltose, Fructose, Glucose?
(ii) What is the difference between fibrous protein and globular protein?
(iii) Write the name of vitamin whose deficiency causes bone deformities in children.

Classify the following compounds as primary, secondary and tertiary halides.
(i) 1-Bromobut-2-ene
(ii) 4-Bromopent-2-ene
(iii) 2-Bromo-2-methylpropane

Indentify A, B, C, D, E, R and R¹ in the following:

Draw the structures of optical isomers of:
(a) [Cr(C₂O₄)₃]^3-
(b) [PtCl₂(en)₂]²⁺
(c) [Cr(NH₃)₂Cl₂(en)]⁺

10.

For the complex [Fe(en)₂Cl₂]Cl, identify the following:
(i) Oxidation number of iron.
(ii) Hybrid orbitals and shape of the complex.
(iii) Magnetic behavior of the complex.
(iv) Number of its geometrical isomers.
(v) Whether there may be optical isomer also.
(vi) Name of the complex.

Multiple Choice Question

10 x 1 = 10

11.

The deficiency of vitamin C causes

(a)

scurvy

(b)

rickets

(c)

pyorrhea

(d)

pernicious anaemia

12.

The number of tripeptides formed by three different amino acids are

(a)

Three

(b)

Four

(c)

Five

(d)

Six

13.

Glycogen is

(a)

a structural polysaccharide

(b)

structurally similar to amylopenctin but extensively branched

(c)

a polymer of \(\beta-D-\)glucose unis

(d)

structurally very much similar to amylopectin

14.

The compound,

C₇H₈ \(\xrightarrow { 3{ CI }_{ 2 }/\triangle } A\xrightarrow { Br_{ 2 }/Fe } B\xrightarrow { Zn/HCI } C\)

The compound C is

(a)

o-Bromotoluene

(b)

m-Bromotoluene

(c)

p-Bromotoluene

(d)

3-Bromo-2,4,6-trichlorotoluene

15.

Best reagent for nuclear iodination of aromatic compounds is

(a)

KI/CH₃COCH₃

(b)

I₂/CH₃CN

(c)

KI/CH₃COOH

(d)

I₂/HNO₃

16.

Which one of the following forms propanenitrile as the major product?

(a)

Ethyl bromide ||+ alcoholic KCN

(b)

Propyl bromide+alcoholic KCN

(c)

Propyl bromide +alcoholic AgCN

(d)

Ethyl bromide+alcoholic AgCN

17.

The oxidation state of nickel in [Ni(CO)₄] is

(a)

(b)

(c)

(d)

18.

Zelse's salt is

(a)

[Fe(C₅H₅)₂]

(b)

[Pb(C₂H₅)₄]

(c)

K[PtCl₃(C₂H₄)]

(d)

[Ni(CO)₄]

19.

\({ Ag }^{ + }+{ NH }_{ 3 }\rightleftharpoons \left[ Ag\left( { NH }_{ 3 } \right) \right] ^{ + }\) ; K₁= 6.8 x 10^-3
\(\left[ Ag\left( { NH }_{ 3 } \right) \right] ^{ + }+{ NH }_{ 3 }\rightleftharpoons \left[ Ag\left( { NH }_{ 3 } \right) _{ 2 } \right] ^{ + }\)
then the formation constant of [Ag(NH₃)₂]⁺ is

(a)

\(1.08\times { 10 }^{ -7 }\)

(b)

\(1.08\times { 10 }^{ -5 }\)

(c)

\(1.08\times { 10 }^{ -9 }\)

(d)

none of these

20.

IUPAC name of [Pt(NH₃)₃Br(NO₂)Cl]Cl is

(a)

Triamminechloridobromidonitroplatinum (IV) chloride

(b)

Triamminebromidonitrochloridoplatinum (IV) chloride

(c)

Triamminebromidochloridonitroplatinum (IV) chloride

(d)

Triamminenitrochloridobromidoplatinum (IV) chloride

Generic 5

3 x 5 = 15

21.

(i) Define:
(a) Metal carbonyls
(b) Chelate
(ii) (a) Give one chemical test as an evidence to show that [Co(NH₃)₅CI]SO₄ and [Co(NH₃)₅(SO₄)] Cl are ionisation isomers.
(b) [NiCl₄]^2- is paramagnetic while [Ni(CO₄] is diamagnetic though both are tetrahedral. Why? (Atomic no. of Ni = 28)
(c) Write the electronic configuration of Fe(III) on the basis of crystal field theory when it forms an octahedral complex in the presence of (i) strong field ligand, and (ii) weak field ligand. (Atomic no. of Fe = 26)

22.

Vitamins represents a group of organic compounds which are needed in small amounts for the healthy growth and maintenance of our body. These are not synthesised by the body and are supplied by the diet. The deficiency of vitamins can be supplemented with medicines.
(i) Which vitamins are water soluble ?
(ii) What are the chemical name of vitamin C and vitamin D ?
(iii) What is the source of vitmain K ?
(iv) How is vitamin K useful ?

23.

What happens when
(i) n-butyl chloride is treated with alcoholic KOH.
(ii) bromobenzene is treated with Mg in the presence o dry ether.
(iii) Chlorobenzene is subjected to hydrolysis.
(iv) methyl bromide is treated with sodium in presence of dry ether.
(v) methyl chloride is treated with KCN?

Assertion and reason

8 x 1 = 8

24.

Assertion: Carbon-halogen bond in aryl halide has partial double bond character.
Reason: Aryl halides undergo nucleophilic substitution easily.
Codes:
A) Assertion and reason both are correct statements and reason is correct explanation for assertion.
B) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C) Assertion is correct statement but reason is wrong statement.
D) Assertion is wrong statement but reason is correct statement.

25.

Assertion: Aryl halide gives a mixture of o-and p-products.
Reason: Aryl halides undergo electrophilic substitutions more readily than benzene.
Codes:
A) Assertion and reason both are correct statements and reason is correct explanation for assertion.
B) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C) Assertion is correct statement but reason is wrong statement.
D) Assertion is wrong statement but reason is correct statement.

26.

Assertion: Alpha (\(\alpha \))-amino acids exist as internal salt in solution as they have amino and carboxylic acid groups in near vicinity.
Reason: H⁺ ion given by carboxylic group (-COOH) is captured by amino group (-NH₂) having lone pair of electrons.
Codes:
(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.

27.

Assertion: DNA has a double helix structure.
Reason: The two strands in a DNA molecule are exactly similar.
Codes:
(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.

28.

Assertion: [Fe(CN)₆]^3- has d²sp³ type hyhridisation.
Reason: [Fe(CN)₆]^3- ion shows magnetic moment corresponding to two unpaired electrons.
Codes:
(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.

29.

In the following questions. an Assertion (A) is followed by a corresponding Reason (R) Use the following keys to choose the appropriate answer.
Assertion (A) In the presence of enzyme, substrate molecule can be attacked by the reagent effectively.
Reason (R) Active sites of enzymes hold the substrate molecule in a suitable position.
Codes:
(a) Both (A) and (R) are correct, (R) is the correct explanation of (A).
(b) Both (A) and (R) are correct, (R) is not the correct explanation of (A).
(c) (A) is correct; (R) is incorrect.
(d) (A) is incorrect; (R) is correct.

30.

In the following questions. an Assertion (A) is followed by a corresponding Reason (R) Use the following keys to choose the appropriate answer.
Assertion (A) The coagulation of egg white occur on boiling.
Reason (R) Denaturation of protein is occur when its native form is subjected to physical change or chemical change.
Codes:
(a) Both (A) and (R) are correct, (R) is the correct explanation of (A).
(b) Both (A) and (R) are correct, (R) is not the correct explanation of (A).
(c) (A) is correct; (R) is incorrect.
(d) (A) is incorrect; (R) is correct.

31.

In the following questions. an Assertion (A) is followed by a corresponding Reason (R) Use the following keys to choose the appropriate answer.
Assertion (A) The total number of isomers shown by \(\begin{equation} \left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+} \end{equation}\) complex ion-is three.
Reason (R) \(\begin{equation} \left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+} \end{equation}\) complex ion has an octahedral geometry.
Codes:
(a) Both (A) and (R) are correct, (R) is the correct explanation of (A).
(b) Both (A) and (R) are correct, (R) is not the correct explanation of (A).
(c) (A) is correct; (R) is incorrect.
(d) (A) is incorrect; (R) is correct.

Case Study Questions

3 x 4 = 12

32.

Complex compounds play an important role in our daily life. Werner's theory of complex compounds says every metal atom or ion has primary valency (oxidation state) which is satisfied by -vely charged ions, ionisable where secondary valency (coordination number) is non-ionisable, satisfied by Iigands (+ve, -ve, neutral) but having lone pair. Primary valency is non-directional, secondary valency is directional. Complex compounds are name according to IUPAC system. Valence bond theory helps in determining shapes of complexes based on hybridisation, magnetic properties, outer or inner orbital complex. Complex show ionisation, linkage, solvate and coordination isomerism also called structural isomerism. Some of them also show stereoisomerism i.e. geometrical and optical isomerism. Ambidentate ligand are essential to show linkage isomerism. Polydentate Iigands form more stable complexes then unidentate Iigands. There are called ehelating agents. EDTA is used to treat lead poisoning, cis-platin as anticancer agents. Vitamin B₁₂ is complex of cobalt. Haemoglobin, oxygen carrier is complex of Fe²⁺ and chlorophyll essential for photosynthesis is complex of Mg²⁺.
(a) What is the oxidation state of Ni in [Ni(CO)₄]?
(b) One mole of CrCI₃ . 6H₂O reacts with excess of AgO₃ to yield 2 mole of AgCI. Write formula of complex. Write IUPAC name also.
(c) Out Cis - [Pt(en)₂ CI₂ ]²⁺ and trans (Ptren), CI₂ )²⁺ which one shows optical isomerism?
(d) Name the hexadentate ligand used for treatment of lead poisoning.
(e) What is hybridisation of [CoF₆]^3- [Co = 27] Give its shape and magnetic properties.
(f) Out [Fe(CO)₅], [Fe(C₂O₄ )₃]^3-, [Fe(H₂O₆)³⁺, [Fe(CN)₆]^3-, which is most stable?
(g) What type of isomerism is shown by [Cr(H₂O)₆] CI₃and [Cr(H₂O)₅ CI] CI₂ . H₂O?

33.

Read the passage given below and answer the following questions:
Carbohydrates can exist in either of two conformations, as determined by the orientation of the hydroxyl group about the asymmetric carbon farthest from the carbonyl.

By convention, a monosaccharide is said to have D-configuration if the hydroxyl group attached to the asymmetric carbon atom adjacent to the - CH₂OH group is on the right hand side irrespective of the positions of the other hydroxyl groups. On the other hand, the molecule is assigned L-configuration if the - OH group attached to the carbon adjacent to the - CH₂OH group is on the left hand side.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) D-Glyceraldehyde and L-Glyc~raldehyde are

(a) epimers	(b) enantiomers
(c) anomers	(d) conformational diasteriomers

(ii) Which of the following monosaccharides, is the majority found in the human body?

(a) D-type

(b) L-type

(c) Both of these

(d) None of these

(iii) Monosaccharides contain

(a) always six carbon atoms	(b) always five carbon atoms
(c) always four carbon atoms	(d) may contain 3 to 7 carbon atoms

(iv) The correct corresponding order of names of four aldoses with configuration given below

respectively, is

(a) L-erythrose, L-threose, L-erythrose, D-threose

(b) D-threose, D-erythrose, L-tl?repse, L-erythrose

(c) L-erythrose, L-threose, D-erythrose, D-threose

(d) D-erythrose, D-threose, L-erythrose, L-threose.

34.

Read the passage given below and answer the following questions:
Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (S_N2) and substitution nucleophilic unimolecular (S_N1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards S_N1 and S_N2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. S_N2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of S_N1 reactions.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) Which of the following is most reactive towards nucleophilic substitution reaction?

(a) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{Cl}\)

(b) \(\mathrm{CH}_{2}=\mathrm{CHCl}\)

(c) \(\mathrm{ClCH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\)

(d) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCl}\)

(ii) Isopropyl chloride undergoes hydrolysis by

(a) S_N1mechanism

(b) S_N2mechanism

(c) S_N1 and S_N2mechanism

(d) neither S_N1 and S_N2mechanism

(iii) The most reactive nucleophile among the following is

(a) CH₃O^-

(b) C₆H₅O^-

(c) (CH₃)₂CHO^-

(d) (CH₃)₃CO^-

(iv) Tertiary alkyl halides are practically inert to substitution by S_N2mechanism because of

(a) insolubility

(b) instability

(c) inductive effect

(d) stearic hindrance.

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Answers Key:

Generic 2

5 x 2 = 10

(i) Peptide linkage: The amide linkage between two a-amino acids formed with the loss of a water molecule is called a peptide linkage.
(ii) The six membered cyclic structure of glucose is called pyranose structure (α - or β -), in analogy with heterocylic compound pyran glucose

Compound (II) is most symmetrical because it has both the -CH₂ groups and Cl atoms para- to each other. Therefore, it fits in the crystal lattice better than the other two isomers and hence it has the highest melting point.

(i) Mg
(ii) Fe
(iii) Co
(iv) Pt

It is because CO can form σ (sigma) as well as π -bond, therefore, it is stronger ligand than CI^-.

Generic 3

5 x 3 = 15

(i) Maltose is disaccharide.
(ii)

Fibrous protein	Globular protein
It consist linear thread like molecules which tend to lie side by side to form fibres. Example: Keratin, collagen	It consist compact form of molecules which are folded together. Example: enzymes, hormones.

(iii) The deficiency of vitamin D causes bone deformities in children.

\((i)\ { { C }H }_{ 3 }CH=CH-\overset { { 1 }^{ \circ } }{ { C } } { H }_{ 2 }Br\ \ (ii){ { C }H }_{ 3 }-\overset { { 2 }^{ \circ } }{ { C } } { H }Br-CH=CH-{ { C }H }_{ 3 }\ \ (iii){ { C }H }_{ 3 }\overset { { 3 }^{ \circ } }{ - } \overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ { CI } } }{ C } } -Br\ \)
1-Bromobut-2-enc 4-Bromopent-2-ene 2-Bromo-2-methylpropane
(1^o Alkyl halide) (2^o Alkyl halide) (3^o Alkyl halide)

(a) [Cr(C₂O₄)₃]^3-

(b) [PtCl₂(en)₂]²⁺

(c) [Cr(NH₃)₂Cl₂(en)]⁺

10.

(i) +3 (III)
(ii) dsp, octahedral
(iii) paramagnetic
(iv) Two geometrical isomers
(v) Yes, there may be optical isomer also due to presence of polydentate ligand.
(vi) Dichlorido bis-(ethane 1, 2-diamine) Iron (III)

Multiple Choice Question

10 x 1 = 10

11.

(a)
scurvy

12.

(d)
Six

13.

(b)
structurally similar to amylopenctin but extensively branched

14.

(b)
m-Bromotoluene

15.

(d)
I₂/HNO₃

16.

(a)
Ethyl bromide ||+ alcoholic KCN

17.

(b)
0

18.

19.

(b)
\(1.08\times { 10 }^{ -5 }\)

20.

(a)
Triamminechloridobromidonitroplatinum (IV) chloride

Generic 5

3 x 5 = 15

21.

(i) (a) Metal carbonyls: Metal carbonyls are the compounds in which carbon monoxide (CO) acts as the ligand. The metal-carbon bond in metal carbonyls possesses both \(\sigma\) and \(\pi\) characters, e.g. N(CO)₄[nickeltetracarbonyl]. Its IUPAC name is tetra carbonyl nickel(0).
(b) Chelate: An inorganic metal complex in which there is a close ring of atoms caused by attachment of a ligand to a metal atom at two points. An example is the complex ion formed between ethylene diamine and cupric ion,[Cu(NH₂CH₂CH₂NH₂)₂]²⁺.

(ii) (a) Add BaCl₂ solution. [Co(NH₃)]₅Cl]SO₄ will give white ppt. of BaSO₄.
\(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{SO}_{4}+\mathrm{BaCl}_{2}(a q) \)\( \longrightarrow\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Cl}\right] \mathrm{Cl}_{2}+\mathrm{BaSO}_{4} \downarrow \)
  \(\text { (White ppt.) }\)
Add AgNO₃(aq) solution [Co(NH₃)₅SO₄] Cl will give white ppt. of AgCl.
\( {\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{Cl}+\mathrm{AgNO}_{3}(a q)} \) \(\longrightarrow \mathrm{AgCl}+\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{NO}_{3} \)
  \(\text { (White ppt) }\)
(c) Fe³⁺ (4s⁰3d⁵) In strong field \( \Delta_{0}>P t_{2 g}^{5} e g^{0} \)
In weak field \(\Delta_{0}

22.

(i) Vitamin B-complex and vitamin C are water soluble vitamins.
(ii) Vitamin C is chemically ascorbic acid while vitamin D is ergocalciferol.
(iii) Green leafy vegetables like spinach, cabbage, carrot etc.
(iv) It is essentially needed for body. The deficiency of vitamin K leads to blood clotting and even harmorrhage

23.

\(\underset { n-Butylchloride }{ { CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }{ CH }_{ 2 }CI } +KOH(alc.)\overset { \triangle }{ \longrightarrow } \underset { But-l-ene }{ { CH }_{ 3 }{ CH }_{ 2 }CH={ CH }_{ 2 }+KCI+{ H }_{ 2 }O } \)

\((iv)\quad { 2CH }_{ 3 }Br+2Na\overset { Dry\quad ether }{ \underset { \quad Wurt\\ reaction }{ \longrightarrow } } \underset { Ethane }{ { CH }_{ 3 }{ CH }_{ 3 } } +2NaBr\)
\(\\ (vi)\quad \underset { Methyl\\ chloride }{ { CH }_{ 3 }CI } +KCN\longrightarrow \underset { Methyl\\ chloride }{ { CH }_{ 3 }CN } +KCI\)

Assertion and reason

8 x 1 = 8

24.

C) Assertion is correct statement but reason is wrong statement.
Explanation:
Aryl halides undergo nucleophilic substitution with difficulty.

25.

C) Assertion is correct statement but reason is wrong statement.
Explanation:
Halogens are somewhat deactivating but o, p-directing. As a result, aryl halides undergo the usual electrophilic substitution reactions less readily than benzene.

26.

\(\text { (a): } \mathrm{NH}_{2}-\mathrm{CH}_{2}-\mathrm{COOH}\) is a typical \(\alpha \) -amino acid.
In solution it exists as, internal salt or zwitter ion,
\(\left(\mathrm{NH}_{3}-\mathrm{CH}_{2}-\mathrm{COO}^{-}\right)\)
because the proton (H⁺) of - COOH group is captured by - NH₂ group as NH₂ has a lone pair of electrons on N atom.

27.

(c): The two strands in a DNA molecule are not exactly similar but are complimentary.

28.

(C): [Fe(CN)₆]^3- ion shows magnetic moment corresponding to one unpaired electron.

29.

(a) In the presence of an enzyme, substrate molecule can be attacked by the reagent effectively because activesites of enzymes hold the substrate moleculein a suitable position. Thus, both (A) and (R) are correct explanation of (A).

30.

(a) When a protein in its native form is subjected to physical change like change in temperature or chemical change like change in pH, the hydrogen bonds are disturbed.
Due to this, globules unfold and helix get uncoiled and protein loses its biological activity. This is called denaturation of protein. The coagulation of egg white on boiling is the common example of denaturation. Thus, both (A)and (R)are correct explanation of (A).

31.

(b) \(\begin{equation} \left[\mathrm{Co}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+} \end{equation}\)exist in cis and trans isomers out of which cis isomer will be optically active (cis-d-isomer) and (cis-l-isomer). Both (A) and (R) are correct but (R) is not the correct explanation of (A).

Case Study Questions

3 x 4 = 12

32.

(a) Zero
(b) [Cr(H₂O)₅Cl]CI₂ . H₂O, pentaaqua chlorido chromium (III) chloride.
(c) Cis - [Pt(en)₂ Cl₂]²⁺ shows optical isomerism.
(d) EDTA^4- (ethylene diamine tetra acetate)
(e) Sp³ d², octahedral, paramagnetic. It is outer orbital complex.
(f) [Fe(CO)₅] is most stable because CO is strongest ligand.
(g) Solvate isomerism.

33.

(i) (b)
(ii) (a)
(iii) (d)
(iv) (d):

34.

(i) (c) : Allylic chlorides are most reactive.
(ii) (c): 2⁰- alkyl halides undergo hydrolysis by S_N1 or S_N2 mechanism.
(iii) (a): Smaller the size of the nucleophile (i.e., CH₃O^-), more reactive it is.
(iv) (d): Stearic hindrance due to bulky alkyl groups prevents the attack of the nucleophile in S_N2 mechanism.