Question Set B

Tamilnadu12th Standard Chemistry Ionic Equilibrium Important Questions Study Material - QB365

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Questions:

Multiple Choice Question

50 x 1 = 50

Boric acid is an acid because its molecule________.

(a)

contains replaceable H⁺ ion

(b)

gives up a proton

(c)

combines with proton to form water molecule

(d)

accepts OH^- from water, releasing proton.

Which among the following is not a borane?

(a)

B₂H₆

(b)

B₃H₆

(c)

B₄H₁₀

(d)

none of these

The element that does not show catenation among the following p-block elements is ________.

(a)

Carbon

(b)

silicon

(c)

Lead

(d)

germanium

Oxidation state of carbon in its hydrides _______.

(a)

(b)

-4

(c)

(d)

Which of the following is not sp² hybridised?

(a)

Graphite

(b)

graphene

(c)

Fullerene

(d)

dry ice

The geometry at which carbon atom in diamond are bonded to each other is _______.

(a)

Tetrahedral

(b)

hexagonal

(c)

Octahedral

(d)

none of these

Which of the following statements is not correct?

(a)

Beryl is a cyclic silicate

(b)

Mg₂SiO₄ is an orthosilicate

(c)

SiO₄⁴⁻is the basic structural unit of silicates

(d)

Feldspar is not aluminosilicate

Column-I		Column-II
A	Borazole	1	B(OH)₃
B	Boric acid	2	B₃N₃H₆
C	Quartz	3	Na₂[B₄O₅(OH)₄]8H₂O
D	Borax	4	SiO₂

(a)

A	B	C	D
2	1	4	3

(b)

A	B	C	D
1	2	4	3

(c)

A	B	C	D
1	2	4	3

(d)

None of these

The compound that is used in nuclear reactors as protective shields and control rods is _________.

(a)

Metal borides

(b)

metal oxides

(c)

Metal carbonates

(d)

metal carbide

10.

The stability of +1 oxidation state increases in the sequence ________.

(a)

Al < Ga < In < Tl

(b)

Tl < In < Ga < Al

(c)

In < Tl < Ga < Al

(d)

Ga< In < Al < Tl

11.

The sum of primary valence and secondary valence of the metal M in the complex [M(en)₂(Ox)]Cl is________.

(a)

(b)

(c)

-3

(d)

12.

An excess of silver nitrate is added to 100ml of a 0.01M solution of Pentaaquachlorochromium (III)chloride. The number of moles of AgCl precipitated would be _______.

(a)

0.02

(b)

0.002

(c)

0.01

(d)

0.2

13.

As per IUPAC guidelines, the name of the complex [Co(en)₂(ONO)Cl]Cl is _______.

(a)

chloro bis ethylenediamine nitrocobalt(III) chloride

(b)

chloridobis(ethane-1, 2-diamine)nitro K-O Cobaltate(III) chloride

(c)

chloridobis(ethane-1, 2-diammine)nitrito K-O Cobalt(II) chloride

(d)

chloridobis(ethane-1, 2-diamine)nitrito K-O Cobalt(III) chloride

14.

IUPAC name of the complex K₃[Al(C₂O₄)₃] is _______.

(a)

potassium trioxalatoaluminium (III)

(b)

possium trioxalatoaluminate (II)

(c)

potassium trisoxalatoaluminate (III)

(d)

potassium trioxalatoaluminate (III)

15.

Crystal field stabilization energy for high spin d⁵ octahedral complex is _______.

(a)

-0.6\({ \Delta }_{ 0 }\)

(b)

(c)

2(P-\({ \Delta }_{ 0 }\))

(d)

2(P+\({ \Delta }_{ 0 }\))

16.

In which of the following coordination entities the magnitude of Δ₀ will be maximum?

(a)

[Co(CN)₆]^3-

(b)

[Co(C₂O₄)₃]^3-

(c)

[Co(H₂O)₆]³⁺

(d)

[Co(NH₃)₆]³⁺

17.

How many geometrical isomers are possible for [Pt(Py)(NH₃)(Br)(Cl)]?

(a)

(b)

(c)

(d)

18.

Which one of the following pairs represents linkage isomers?

(a)

[Cu(NH₃)₄][PtCl₄] and [Pt(NH₃)₄][CuCl₄]

(b)

[Co(NH₃)₅(NO₃)]SO₄ and [Co(NH₃)₅(ONO)]

(c)

[Co(NH₃)₄(NCS)₂]Cl and [Co(NH₃)₄(SCN)₂]Cl

(d)

both (b) and (c)

19.

A complex in which the oxidation number of the metal is zero is_______.

(a)

K₄[Fe(CN)₆]

(b)

[Fe(CN)₃(NH₃)₃]

(c)

[Fe(CO)₅]

(d)

both (b) and (c)

20.

Formula of tris(ethane-1, 2-diamine)iron(II)phosphate _______.

(a)

[Fe(CH₃-CH(NH₂)₂)₃](PO₄)₃

(b)

[Fe(H₂N-CH₂-CH₂-NH₂)₃](PO₄)

(c)

[Fe(H₂N-CH₂-CH₂-NH₂)₃](PO₄)₂

(d)

[Fe(H₂N-CH₂-CH₂-NH₂)₃]₃(PO₄)₂

21.

Concentration of the Ag⁺ ions in a saturated solution of Ag₂C₂O₄ is 2.24 ×10^-4mol L^-1 solubility product of Ag₂C₂O₄ is_______.

(a)

2.42 × 10^-8mol³L^-3

(b)

2.66 × 10^-12mol³L^-3

(c)

4.5 × 10^-11mol³L^-3

(d)

5.619 × 10^-12mol³L^-3

22.

pH of a saturated solution of Ca(OH)₂ is 9. The Solubility product (K_sp) of Ca(OH)₂ _______.

(a)

0.5 × 10^-15

(b)

0.25 × 10^-10

(c)

0.125 × 10^-15

(d)

0.5 × 10^-10

23.

Conjugate base for Bronsted acids H₂O and HF are _______.

(a)

OH^- and H₂FH⁺, respectively

(b)

H₃O⁺ and F^-, respectively

(c)

OH^- and F^-, respectively

(d)

H₃O⁺ and H₂F⁺, respectively

24.

Which of the following fluro compounds is most likely to behave as a Lewis base?

(a)

BF₃

(b)

PF₃

(c)

CF₄

(d)

SiF₄

25.

Which of these is not likely to act as Lewis base?

(a)

BF₃

(b)

PF₃

(c)

(d)

F^–

26.

The percentage of pyridine (C₅H₅N) that forms pyridinium ion (C₅H₅NH) in a 0.10M aqueous pyridine solution _______.(K_b for C₅H₅N = 1.7×10^-9) is

(a)

0.006%

(b)

0.013%

(c)

0.77%

(d)

1.6%

27.

The solubility of AgCl (s) with solubility product 1.6 × 10^-10 in 0.1M NaCl solution would be _______.

(a)

1.26 × 10^-5M

(b)

1.6 × 10^-9M

(c)

1.6 × 10^-11M

(d)

Zero

28.

What is the pH of the resulting solution when equal volumes of 0.1M NaOH and 0.01M HCl are mixed?

(a)

2.0

(b)

(c)

7.0

(d)

12.65

29.

The dissociation constant of a weak acid is 1 × 10^-3. In order to prepare a buffer solution with a pH = 4, the [Acid]/[Salt] ratio should be _______.

(a)

4:3

(b)

3:4

(c)

10:1

(d)

1:10

30.

H₂PO₄^- the conjugate base of _______.

(a)

PO₄³⁻

(b)

P₂O₅

(c)

H₃PO₄

(d)

HPO₄^2-

31.

Which of the following can act as Lowery – Bronsted acid well as base?

(a)

HCl

(b)

SO₄²⁻

(c)

HPO₄²⁻

(d)

Br^-

32.

Which of the following relation is correct for degree of hydrolysis of ammonium acetate?

(a)

\(h=\sqrt { \frac { { K }_{ h } }{ C } } \)

(b)

\(h=\sqrt { \frac { { K }_{ a } }{ K_b } } \)

(c)

\(h=\sqrt { \frac { { K }_{ w } }{ { K }_{ a }.{ K }_{ b } } } \)

(d)

\(h=\sqrt { \frac { { { K }_{ a }.{ K }_{ b } } }{ { K }_{ w } } } \)

33.

Dissociation constant of NH₄OH is 1.8 x 10^-5 the hydrolysis constant of NH₄Cl would be _______.

(a)

1.8 × 10^-19

(b)

5.55 × 10^-10

(c)

5.55 × 10^-5

(d)

1.80 × 10^-5

34.

An alcohol (x) gives blue colour in victormayer’s test and 3.7g of X when treated with metallic sodium liberates 560 mL of hydrogen at 273 K and 1 atm pressure what will be the possible structure of X?

(a)

CH₃ CH (OH) CH₂CH₃

(b)

CH₃ – CH (OH) – CH₃

(c)

CH₃ – C (OH) – (CH₃)₂

(d)

CH₃- CH₂ –CH (OH) – CH₂– CH₃

35.

Which of the following compounds on reaction with methyl magnesium bromide will give tertiary alcohol.

(a)

benzaldehyde

(b)

propanoic acid

(c)

methyl propanoate

(d)

acetaldehyde

36.

The X is _______.

(a)

(b)

(c)

(d)

None of these

37.

In the reaction sequence, Ethane \(\overset { HOCl }{ \longrightarrow } A\overset { x }{ \longrightarrow } \) ethan -1, 2 - diol. A and X respectively are ________.

(a)

Chloroethane and NaOH

(b)

ethanol and H₂SO₄

(c)

2 – chloroethan -1-ol and NaHCO₃

(d)

ethanol and H₂O

38.

Which one of the following is the strongest acid.

(a)

2 - nitrophenol

(b)

4 – chlorophenol

(c)

4– nitrophenol

(d)

3 – nitrophenol

39.

on treatment with Con H₂SO₄, predominately gives______.

(a)

(b)

(c)

(d)

40.

Carbolic acid is _____.

(a)

Phenol

(b)

Picri cacid

(c)

benzoic acid

(d)

phenylacetic acid

41.

Which one of the following will react with phenol to give salicyladehyde after hydrolysis.

(a)

Dichlo methane

(b)

trichloroethane

(c)

trichloro methane

(d)

CO₂

42.

(CH₃)₃-C-CH(OH) CH₃ \(\overset { con{ H }_{ 2 }{ SO }_{ 4 } }{ \longrightarrow } \)X (major product)

(a)

(CH₃)₃ CCH = CH₂

(b)

(CH₃)₂C = C (CH₃)₂

(c)

CH₂= C(CH₃)CH₂-CH₂- CH₃

(d)

CH₂= C (CH₃) - CH₂- CH₂- CH₃

43.

The correct IUPAC name of the compound

(a)

4 – chloro – 2,3 – dimethyl pentan – 1-ol

(b)

2,3 – dimethyl – 4- chloropentan -1-ol

(c)

2,3,4 – trimethyl – 4- chlorobutan -1-ol

(d)

4– chloro – 2,3,4 – trimethyl pentan – 1-ol

44.

In the reaction Ethanol \(\overset { { PCl }_{ 5 } }{ \longrightarrow } X\overset { alc.KOH }{ \longrightarrow } Y\overset { { H }_{ 2 }{ SO }_{ 4 }/{ H }_{ 2 }O }{ \underset { 298k }{ \longrightarrow } } Z.\) The ‘Z’ is ______.

(a)

ethane

(b)

ethoxyethane

(c)

ethylbisulphite

(d)

ethanol

45.

HO CH₂ CH₂ – OH on heating with periodic acid gives ______.

(a)

methanoic acid

(b)

Glyoxal

(c)

methanol

(d)

CO₂

46.

Which of the following compound can be used as antifreeze in automobile rediators?

(a)

methanol

(b)

ethanol

(c)

Neopentyl alcohol

(d)

ethan -1, 2-diol

47.

One mole of an organic compound (A) with the formula C₃H₈O reacts completely with two moles of HI to form X and Y. When Y is boiled with aqueous alkali it forms Z. Z answers the iodoform test. The compound (A) is ______.

(a)

propan – 2-ol

(b)

propan -1-ol

(c)

ethoxy ethane

(d)

methoxy ehane

48.

Among the following ethers which one will produce methyl alcohol on treatment with hot HI?

(a)

(H₃C)₃C-O-CH₃

(b)

(CH₃-)₂-CH-CH₂-O-CH₃

(c)

CH₃-(CH₂)₃-O-CH₃

(d)

CH₃-CH₂-\(\underset { \overset { | }{ { CH }_{ 3 } } }{ CH } \)-O-CH₃

49.

On reacting with neutral ferric chloride, phenol gives ______.

(a)

red colour

(b)

violet colour

(c)

dark green colour

(d)

no colouration.

50.

Isoprophylbenzene on air oxidation in the presence of dilute acid gives ______.

(a)

C₆H₅COOH

(b)

C₆H₅COCH₃

(c)

C₆H₅COC₆H₅

(d)

C₆H₅- OH

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Answers Key:

Multiple Choice Question

50 x 1 = 50

(d)
accepts OH^- from water, releasing proton.

(b)
B₃H₆

(a)
+4

(d)
dry ice

(a)
Tetrahedral

(d)
Feldspar is not aluminosilicate

(a)

A B C D

2 1 4 3

(a)
Metal borides

10.

(a)
Al < Ga < In < Tl

11.

In the complex [M(en)₂(Ox)]Cl For the central metal ion M3+
The primary valence is = +3
The secondary valence = 6
sum of primary valence and secondary valence = 3 + 6 = 9

12.

The complex is [M(H₂O)₅Cl]Cl₂
1000 ml of 1 M solution of the complex gives 2 moles of Cl^- ions 1000 ml of 0.01 M solution of the complex will give
\(\frac{100 ml \times 0.01M \times 2Cl^-}{1000 ml \times 1M}\)
= 0.002 moles of Cl^- ions

13.

(d)
chloridobis(ethane-1, 2-diamine)nitrito K-O Cobalt(III) chloride

14.

(d)
potassium trioxalatoaluminate (III)

15.

The electronic configuration t_2g³, e²_g
[ 3 x (-0.4)+ 2(0.6)]Δ₀
[-1.2 + 1.2] Δ₀ = 0

16.

In all the complexes, the central metal ion is Co³⁺, among the given ligands CN^- is the strongest ligand, which causes large crystal
field splitting i.e maximum Δ₀

17.

Three isomers. If we consider any one of the ligands as reference (say Py), the arrangement of other three ligands (NH₃, Br^- and Cl^-) with respect to (Py) gives three geometrical isomers.

18.

(a) coordination isomers
(b) no isomerism ( different molecular formula)
(c)⬅NCS; ⬅SCN coordinating atom differs : linkage isomers

19.

a) Fe²⁺ b) Fe³⁺ c) Fe⁰

20.

[Fe(H₂N-CH₂-CH₂-NH₂)₃]₃(PO₄)₂
[Fe(en)₃]²⁺(\(PO_{4}^{3-}\))

21.

\(\mathrm{Ag}_{2} \mathrm{C_2O_4} \rightleftharpoons 2 \mathrm{Ag}_{}^{+}+\mathrm{C_2O}_{4{}}^{2-}\)
\(\left[\mathrm{Ag}^{+}\right]=2 .24 \) ×10^-4mol L^-1
\(\mathrm{C_2O}_{4{}}^{2-} = \frac {2.24 \times 10 ^{-4}}{2}\) mol L^-1
= 1.12 ×10^-4mol L^-1
K_sp = [Ag]² [C₂O₄^2-]
= (2.24 ×10^-4mol L^-1) (1.12 ×10^-4mol L^-1)
= 5.619 × 10^-12mol³L^-3

22.

Ca(OH)₂ ⇌ Ca²⁺ + 2OH^-
Given that pH = 9
pOH = 14 - 9 = 5
[pOH = - log₁₀ [OH]]
[OH^-] = 10^[pOH]
[OH] = 10^-5 M
Ksp = [Ca²⁺] [OH^-]
= 10^-5/2 x (10^-5)² = 0.5 x 10^-15

23.

H₂O + H₂O ⇌ H₃O⁺ + OH^-
acid 1 base 1 acid 2 base 2
HF + H₂O ⇌ H₃O⁺ + F^-
acid 1 base 1 acid 2 base 2
∴ Conjugate bases are OH^- and F^- respectively.

24.

BF₃ → electron deficient → Lewis acid
PF₃ → electron rich → Lewis base
CF₄ → neutral → neither Lewis acid nor base
SiF₄ → neutral → neither Lewis acid nor base

25.

BF₃ → electron deficient → Lewis acid
PF₃ → electron rich → Lewis base
CO → having lone pair of electron → Lewis base
F → unshared pair of electron → Lewis base

26.

C₅H₅N + H-OH ⇌ C₅H₅ ⁺NH + OH^-
\(\frac { { \alpha }^{ 2 }{ C } }{ 1-\alpha } =K_b\)
\(\alpha\)²C \(\approx\) K_b
\(\alpha = \sqrt {\frac{K_b} C} = \sqrt {\frac{1.7 \times 10^{-9}} {0.1}}\)
\(= \sqrt{1.7} \times 10^{-4}\)
Percentage of dissociation =\(= \sqrt{1.7} \times 10^{-4}\) x 100
= 1.3 x 10^-2 = 0.013%

27.

AgCl_(s) ⇌ Ag⁺_(aq) + Cl^-_(aq)
NaCl → Na⁺ +Cl^-
0.1M 0.1M 0.1M
K_sp = 1.6 × 10^-10
K_sp = [Ag⁺][ Cl^-]
K_sp = (s) (s + 0.1)
0.1 >>> s
∴ s + 0.1 = 0.1
∴ s = 1.6 × 10^-10/ 0.1 = 1.6 × 10^-9

28.

x ml of 0.1 M NaOH + x mL of 0.01 M HCI
No. of moles of NaOH = 0.1 x X x 10^-3
= 0.1 X x 10^-3
No. of moles of HCI = 0.01 x X x 10^-3
= 0.01 X x 10^-3
No. of moles of NaOH after mixing
= 0.1 X x 10^-3 - 0.01 X x 10^-3
= 0.09 X x 10^-3
Concentration of NaOH\(= (\frac{0.09x \times 10^{-3}}{2x \times 10^{-3}}) = 0 .045\)
[OH^-] = 0.045
pOH =-log (4.5 x 10^-2)
= 2 -log 4.5
= 2 - 0.65 = 1.35
pH = 14 - 1.35 = 12.65

29.

K_a = 1 × 10^-3
pH = 4
[Acid]/[Salt] = ?
pH = pK_a+ log [Acid]/[Salt]
4 = -log₁₀ (1 x 10^-3) + log [Acid]/[Salt]
4 = 3 + log [Acid]/[Salt]
1 = log₁₀ [Acid]/[Salt]
[Acid]/[Salt] = 10¹
i.e., [Acid]/[Salt] = 1/10
1 : 10

30.

H₃PO₄ + H - OH ⇌ H₃O⁺ + H₂PO₄^-
acid 1 base 1 acid 2 base 2
\(\therefore\) H₂PO₄^- the conjugate base of H₃PO₄

31.

HPO₄²⁻ can have the ability to accept a proton to form H₂PO₄^-
It can also have the ability to donate a proton to form PO₄^-3

32.

33.

\(K_h= { \frac { { K }_{ w } }{ K_b } } = \frac{1 \times 10^{-14}}{1.8 \times 10^{-5}}\)
= 0.55 x 10^-9 = 5.5 x 10^-10

34.

CH₃ CH (OH) CH₂CH₃
2R-OH+ 2Na ⟶ 2RONa + H₂ ↑
2 moles of alcohol gives 1 mole of H₂ which occupies 22.4 L at 273 K and 1 atm number of moles of alcohol
= 2 moles of R -OH/22.4L of H₂ x 560 ml
= 0.05 moles
No of moles = mass/molar mass = m/M
= 3.7/0.05 = 74 g mol^-1
General formula for (R-OH) Cn H_{2n + 1}OH
n(12) + (2n + 1) (1) + 16 + 1 = 74
14n = 74 - 18
14n = 56
n = 56/14 = 4
The "2" alcohol which contains 4 carbon is CH₃ - CH (OH) CH₂ - CH₃