Question Set C

cbse 12th Standard Chemistry d- and f- Block Elements Model Questions Papers Study Material - QB365

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Questions:

Multiple Choice Question

50 x 1 = 50

In which of the following does the central atom exhibit an oxidation state of +3?

(a)

K₂[Ni (CN)₄]

(b)

K₄[Fe(CN)₆]

(c)

[Fe₂(C₂O₄)₃]^3-

(d)

[Cu(NH₃)₄]²⁺

CO is stronger ligand than Cl^- because

(a)

CO is neutral molecule

(b)

CO has \(\pi\)-bond

(c)

CO is poisonous

(d)

CO is more reactive

Correct increasing order of wavelength of absorption in visible region for cornplex of Co³⁺ is

(a)

\( {\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+},\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}} \)

(b)

\({\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+},\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+}} \)

(c)

\({\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+},\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}} \)

(d)

\({\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{NH}_{6}\right)_{6}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}} \)

The oxidation state of Cr in final product formed by reaction of KI and acidified dichromate solution is

(a)

(b)

(c)

(d)

The number of moles of KMnO₄ that will be needed to react with one mole of SO₃^2- in acidic solution.

(a)

(b)

3/5

(c)

4/5

(d)

2/5

Structure of [Ni(CO)₄] is

(a)

tetrahedral

(b)

square planar

(c)

octahedral

(d)

None of these

For d⁴ions, the fourth electron enters one of the e_g orbitals giving the configuration t_2g³ e_g¹when,

(a)

Δ_o > P

(b)

Δ_o < P

(c)

Δ_o = P

(d)

Δ_o \(\geq \) P

Aman made white silvery metal radioactive in nature has strong tendency to form oxocations and complexes. It is used as a nuclear fuel in atomic reactor. This metal is a

(a)

actinide

(b)

lanthanide

(c)

representative element

(d)

transition metal

Which of the following has abnormally low value of third ionisation enthalpy.

(a)

Lanthanum

(b)

Gadolinium

(c)

Lutetium

(d)

All of the above

10.

When acidified K₂Cr₂O₇solution is added to Sn²⁺ salt then Sn²⁺changes to

(a)

(b)

Sn³⁺

(c)

Sn⁴⁺

(d)

Sn⁺

11.

Which of the following is the correct order of second ionization energy ?

(a)

V>Cr>Mn

(b)

V<Cr<Mn

(c)

V<Cr>Mn

(d)

V>Cr<Mn

12.

Which element do you expect to have the highest melting point ?

(a)

(b)

(c)

(d)

13.

Which of the following statements are correct when a mixture of NaCI and K₂Cr₂O₇ is gently warmed with conc. H₂SO₄ ?

(a)

a deep red vapour is evolved

(b)

The vapour when passed into NaOH solution gives yellow solution of Na₂CrO₄

(c)

chlorine gas is evolved

(d)

chromyl chloride is formed

14.

The colour of the transition metal ions is due to

(a)

d - d transition

(b)

charge transfer

(c)

change in the geometry

(d)

none

15.

Reason of lanthanoid contraction is

(a)

negligible screening effect of 'f' - orbitals

(b)

increasing nuclear charge

(c)

decreasing nuclear charge

(d)

decreasing screening effect

16.

The colour of KMnO₄ is due to

(a)

\(L\rightarrow M \) charge transfer transition

(b)

\(\sigma \rightarrow { \sigma }^{ * }\) transition

(c)

\(M\rightarrow L\) charge transfer transition

(d)

\(d \rightarrow d\) transition.

17.

Identify the product and its colour when MnO₂ is fused with solid KOH in the presence of O₂

(a)

KMnO₄, purple

(b)

K₂MnO₄, dark green

(c)

MnO, colourless

(d)

Mn₂O₃, brown

(e)

MnO₂, black

18.

Which of the following compounds will not give positive chromyl test ?

(a)

CuCI₂

(b)

HgCI₂

(c)

ZnCI₂

(d)

C₆H₅⁺NH₃CI^-

19.

A mixture of salts (Na₂SO₃+K₂Cr₂O₇ ) in a test tube is treated with dil. H₂SO₄ and resulting gas is passed through lime water. Which of the following observations is correct about this test ?

(a)

Solution in test tube becomes green and lime water turns milky

(b)

Solution in test tube is colourless and lime water turns milky

(c)

Solution in test tube becomes green and lime water remains clear

(d)

Solution in test tube remains clear and lime water also remains clear.

20.

The acidic, basic or amphoteric nature of Mn₂O₇ , V₂O₅ and CrO are respectively

(a)

acidic, acidic and basic

(b)

basic, amphoteric and acidic

(c)

acidic, amphoteric and basic

(d)

acidic, basic and amphoteric

(e)

acidic, basic and basic

21.

Which of the following statement(s) is/are correctly applicable to all the transition elements with atomic numbers 21 - 29 ?

1. The lowest oxidation state +1

2. The 4s orbital is completely filled in the ground state.

3. The 3d orbital is incompletely filled in the ground state.

4. The ion in the +2 oxidation state is paramagnetic.

(a)

1,2 and 3

(b)

3 and 4 only

(c)

4 only

(d)

3 only

22.

Among the following compounds that is both paramagnetic and coloured is

(a)

K₂Cr₂O₇

(b)

(NH₄)₂[TiCI₆]

(c)

VOSO₄

(d)

K₃[Cu(CN)₄]

23.

Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other, in

(a)

Ti⁺,Ti³⁺

(b)

Cu⁺,Cu²⁺

(c)

Cr²⁺,Cr³⁺

(d)

V²⁺,VO²⁺

24.

The correct order of \({ E }_{ { M }^{ 2+ }/M }^{ o }\) values with negative for the four successive elements Cr, Mn, Fe and Co is

(a)

Fe>Mn>Cr>Co

(b)

Cr>Mn>Fe>Co

(c)

Mn>Cr>Fe>Co

(d)

Cr>Fe>Mn>Co

25.

General electronic configuration of actinoids is (n - 2) f^1-14 (n - 1) d^0-2 ns². Which of the following actinoids have one electron in 6d orbital?

(a)

U (Atomic no. 92)

(b)

Np (Atomic no. 93

(c)

Pu (Atomic no. 94)

(d)

Am (Atomic no. 95)

26.

Highest oxidation state of manganese in fluoride is +4 (MnF₄) but highest oxidation state in oxides is +7 (Mn₂O₇ ) because ............ .

(a)

fluorine is more electronegative than oxygen

(b)

fluorine does not possess d - orbitals

(c)

fluorine stabilise lower oxidation state

(d)

in covalent compounds, fluorine can form single bond only while oxygen forms double bond

27.

Metallic radii of some transition elements are given below. Which of these elements will have hig

Element	Fe	Co	Ni	Cu
Metallic	126	125	125	128

(a)

(b)

(c)

(d)

28.

Electronic configuration of a transition element X in +3 oxidation state is [Ar] 3d⁵. What is its atomic number ?

(a)

(b)

(c)

(d)

29.

Which of the following complexes show linkage isomerism ?

(a)

\([Co(NH_3)_5(NO_2)]^{2+}\)

(b)

\([Co(H_2O)_5CO]^{3+}\)

(c)

\([Cr(NH_3)_5SCN]^{2+}\)

(d)

\([Fe(en)_2Cl_2]^+\)

30.

Which of the following options are correct for \([Fe(CN)_6]^{3-}\) complex ?

(a)

d ²sp³ hybridisation

(b)

sp³d² hybridisation

(c)

paramagnetic

(d)

diamagnetic

31.

A, B and C are three complexes of chromium (III) with the empirical formula H₁₂O₆Cl₃Cr. All the three complexes have water and chloride ions as ligands. Complex A does not react with conc. H₂SO₄ whereas complexes B and C lose 6.75% and 13.5% of their original weight respectively, on treatment with concentrated H₂SO₄.
The complex A is

(a)

[Cr(H₂O)₄(H)₄(O)₂]Cl₃

(b)

[Cr(H₂O₅)₅(H)₂(O)]Cl₃

(c)

[Cr(H₂O)₆]Cl₃

(d)

[Cr(H₂O)₅Cl]Cl₂.H₂O

32.

The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?

(a)

[Fe(CO)₅]

(b)

[Fe(CN)₆]^3-

(c)

[Fe(C₂O₄)₃]^3-

(d)

[Fe(H₂O)₆]³⁺

33.

The colour of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of wavelength of light in the visible region for the complexes, [Co(NH₃)₆]³⁺, [Co(CN)₆]^3-, [Co(H₂O)₆]³⁺

(a)

[Co(CN)₆]^3- > [Co(NH₃)₆]³⁺ > [Co(H₂O)₆]³⁺

(b)

[Co(NH₃)₆]³⁺ > [Co(H₂O)₆]³⁺ > [Co(CN)₆]^3-

(c)

[Co(H₂O)₆]³⁺ > [Co(NH₃)₆]³⁺ > [Co(CN)₆]^3-

(d)

[Co(CN)₆]^3- > [Co(NH₃)₆]³⁺ > [Co(H₂O)₆]³⁺

34.

The equation which is balanced and represents the correct product(s) is

(a)

CuSO₄ + 4 KCN \(\rightarrow \) K₂[Cu(CN)₄] + K₂SO₄

(b)

Li₂O + 2 KCl \(\rightarrow \) 2 LiCl + K₂O

(c)

[CoCl(NH₃)₅]⁺ + 5H⁺ \(\rightarrow \) Co²⁺+ 5 \({ NH }_{ 4 }^{ + }\) + Cl^-

(d)

[Mg(H₂O)₆]²⁺ + (EDTA)^4- \(\overset { excess\quad NaOH }{ \rightarrow } \) [Mg(EDTA)]²⁺ + 6 H₂O

35.

When excess ammonia is added to CuSo₄ solution, the deep blue complex obtained is

(a)

tetrahedral and paramagnetic

(b)

tetrahedral and diamagnetic

(c)

square planar and diamagnetic

(d)

square planar and paramagnetic

(e)

tetrahedral and ferromagnetic

36.

Which of the following carbonyls will have the strongest C-O bond?

(a)

\({ MN(CO) }_{ 6 }^{ + }\)

(b)

Cr(CO)₆

(c)

\({ V(CO) }_{ 6 }^{ - }\)

(d)

Fe(CO)₅

37.

Among the following complexes, the one which shows zero crystal field stabilization energy (CFSE) is

(a)

[Mn(H₂O)₆]³⁺

(b)

[Fe(H₂O)₆}³⁺

(c)

[Co(H₂O)₆]²⁺

(d)

[Co(H₂O)₆]³⁺

38.

[Cr(H₂O)₆]Cl₃ (at.no. of Cr = 24) has a magnetic moment of 3.83 B.M. The correct distribution of 3d electrons in the chromium of the complex is

(a)

\({ 3d }_{ xy }^{ 1 },{ 3d }_{ yz }^{ 1 },{ 3d }_{ xz }^{ 1 }\)

(b)

\({ 3d }_{ xy }^{ 1 },{ 3d }_{ yz }^{ 1 },{ 3d }_{ z ^2}^{ 1 }\)

(c)

\({ 3d }_{ (x^2-y^2)}^{ 1 },{ 3d }_{ z^2 }^{ 1 },{ 3d }_{ xz }^{ 1 }\)

(d)

\({ 3d }_{ xy}^{ 1 },{ 3d }_{ (x^2-y^2) }^{ 1 },{ 3d }_{ yz }^{ 1 }\)

39.

A solution containing 0.319 g of CrCl₃.6 H₂O was passed through a cation exchange resin and acid coming out of the cation exchange resin required 28.5 ml of 0.125 M NaOH. Determine correct formula of the complex [Mol.wt, of the complex = 266.5]

(a)

[Cr(H₂O)₆]Cl₃

(b)

[Cr(H₂O)₅Cl]H₂O.Cl₂

(c)

[Cr(H₂O)₄Cl₂]Cl.2 H₂O

(d)

[Cr(H₂O)₃Cl₃].3H₂O

40.

[Co(NH₃)₄(NO₂)₂]Cl exhibits

(a)

ionization isomerism, geometrical isomerism and optical isomerism

(b)

linkage isomerism, geometrical isomerism and optical isomerism

(c)

linkage isomerism, ionization isomerism and optical isomerism

(d)

linkage isomerism, ionization isomerism and geometrical isomerism

41.

The number of geometrical isomers that can exist for square planer [Pt(Cl) (py) (NH₃) (NH₂OH)]⁺is (py=pyridine)

(a)

(b)

(c)

(d)

42.

Which one of the following is a homoleptic complex?

(a)

tris(ethane-1, 2-diamine) cobalt (III) chloride

(b)

triamminetriaquachromium (III) chloride

(c)

diamminechloridonitro-N-Platinum(II)

(d)

dichlorido bis(ethane-1, 2-diamine ) cobalt(III)

(e)

pentaamminecarbonato cobalt (III) chloride

43.

The metal-carbon bond in metal carbonyls possesses

(a)

only \(\sigma \) character

(b)

only \(\pi \) character

(c)

both \(\sigma \) and \(\pi \) character

(d)

ionic character

44.

The correct structure of Fe(CO)₅ is

(a)

octahedral

(b)

terahedral

(c)

square pyramidal

(d)

trigonal bipyramidal

45.

Prussian blue is obtained by mixing together aqueous solution of Fe³⁺ salt with

(a)

Ferricyanide

(b)

Ferocyanide

(c)

Hydrogen cyanide

(d)

Sodium cyanide

46.

The dark blue colour of the solution formed when excess of ammonia is added to a solution of copper (II) sulphate is due to the presence of the ion

(a)

[Cu(OH)₄ (H₂O)₂]^2-

(b)

[Cu(H₂O)₆]²⁺

(c)

[Cu(NH₃)₂ (H₂O)₄]²⁺

(d)

[Cu(NH₃)₄ (H₂O)₂]²⁺

47.

The hybridisation of Fe in K₄[Fe(CN)₆] is

(a)

dsp²

(b)

sp³

(c)

d²sp³

(d)

sp³d²

48.

An example of ambidentate ligand is

(a)

Ammine

(b)

Aquo

(c)

Oxalato

(d)

Thiacyanato

49.

Which of the following factor may be regarded as the main cause of lanthanide contraction ?

(a)

Poor shielding of one of the 4f - electrons by another in the subshell

(b)

Effective shielding of one of the 4f - electrons by another in the subshell

(c)

Poorer shielding of 5d electrons by 4f electrons

(d)

Greater shielding of 5d electrons by 4f electrons.

50.

Which of the following ion is colourless in aqueous solution ?

(a)

Fe²⁺

(b)

Mn²⁺

(c)

Ti³⁺

(d)

Sc³⁺

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Answers Key:

Multiple Choice Question

50 x 1 = 50

(b)
CO has \(\pi\)-bond

(d)
\({\left[\mathrm{Co}(\mathrm{en})_{3}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{NH}_{6}\right)_{6}\right]^{3+},\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}} \)

(d)
+3

(d)
2/5

(a)
tetrahedral

(b)
Δ_o < P

(a)
actinide

10.

11.

12.

(b)
W

13.

(a)
a deep red vapour is evolved

14.

(a)
d - d transition

15.

(a)
negligible screening effect of 'f' - orbitals

16.

(a)
\(L\rightarrow M \) charge transfer transition

17.

(b)
K₂MnO₄, dark green

18.

(b)
HgCI₂

19.

20.

21.

22.

23.

(a)
Ti⁺,Ti³⁺

24.

25.

(a)
U (Atomic no. 92)

26.

(d)
in covalent compounds, fluorine can form single bond only while oxygen forms double bond

27.

(d)
Cu

28.

(b)
26

29.

(a)
\([Co(NH_3)_5(NO_2)]^{2+}\)

30.

(a)
d ²sp³ hybridisation

31.

32.

33.

34.

35.

(d)
square planar and paramagnetic

36.

(a)
\({ MN(CO) }_{ 6 }^{ + }\)

37.

(b)
[Fe(H₂O)₆}³⁺

38.

(a)
\({ 3d }_{ xy }^{ 1 },{ 3d }_{ yz }^{ 1 },{ 3d }_{ xz }^{ 1 }\)

39.

(a)
[Cr(H₂O)₆]Cl₃

40.

(d)
linkage isomerism, ionization isomerism and geometrical isomerism

41.

(d)
3

42.

(a)
tris(ethane-1, 2-diamine) cobalt (III) chloride

43.

44.

45.

(b)
Ferocyanide

46.

(d)
[Cu(NH₃)₄ (H₂O)₂]²⁺

47.

48.

(d)
Thiacyanato

49.

(a)
Poor shielding of one of the 4f - electrons by another in the subshell

50.

(d)
Sc³⁺

cbse 12th Standard Chemistry d- and f- Block Elements Model Questions Papers Study Material - QB365 Set C

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Std: 12th Standard CBSE - Chemistry

chapter: d- and f- Block Elements - Model Questions Papers

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