Question Set B

TN 12th Standard Chemistry Ionic Equilibrium Creative Questions Study Material - QB365

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Questions:

Multiple Choice Question

50 x 1 = 50

Henderson - Hasselbalch equation is ______.

(a)

\(\mathrm{pH}=\mathrm{pK}_{\mathrm{a}}+\log \frac{[\mathrm{salt}]}{[\mathrm{acid}]}\)

(b)

\(\mathrm{pH}=\mathrm{pK}_{\mathrm{a}}+\log \frac{[\mathrm{salt}]}{[\mathrm{base}]}\)

(c)

\(\mathrm{pH}=\mathrm{pK}_{\mathrm{a}}+\log \frac{[\text { acid }]}{[\mathrm{salt}]}\)

(d)

\(\mathrm{pOH}=\mathrm{pK}_{\mathrm{b}}+\log \frac{[\text { base }]}{[\mathrm{salt}]}\)

The electronic configuration of polonium is ______.

(a)

[He] 2s²2p⁴

(b)

[Ne] 3s²3p⁴

(c)

[Xe] 4f¹⁴5d¹⁰6s²6p⁴

(d)

[Ar] 3d¹⁰4s²5p⁴

The number of secondary alcoholic group in glycerol is _______.

(a)

(b)

(c)

(d)

Terylene is an example of _______.

(a)

polyamide

(b)

polythene

(c)

polyester

(d)

polysaccharide

Aspirin is a/an _______.

(a)

acetylsalicylic acid

(b)

benzoyl salicylic acid

(c)

chlorobenzoic acid

(d)

anthranilic acid

Which of the following is an analgesic?

(a)

Streptomycin

(b)

Chloromycetin

(c)

Asprin

(d)

Penicillin

Complete hydrolysis of cellulose gives ______.

(a)

L-Glucose

(b)

D-Fructose

(c)

D-Ribose

(d)

D-Glucose

The number of sp² and sp³ hybridised carbon in fructose are respectively ______.

(a)

1 and 4

(b)

4 and 2

(c)

5 and 1

(d)

1 and 5

Among the following the achiral amino acid is ______.

(a)

2-ethylalanine

(b)

2-methylglycine

(c)

2-hydroxymethylserine

(d)

Tryptophan

10.

The order of basic strength for methyl substituted amines in aqueous solution is _________.

(a)

N(CH₃)₃> N(CH₃)₂H> N(CH₃)H₂> NH₃

(b)

N(CH₃)H₂>N(CH₃)₂H > N(CH₃)₃>NH₃

(c)

NH₃> N(CH₃)H₂> N(CH₃)₂ H>N(CH₃)₃

(d)

N(CH₃)₂H>N(CH₃)H₂> N(CH₃)₃> NH₃

11.

The product formed by the reaction an aldehyde with a primary amine ________.

(a)

carboxylic acid

(b)

aromatic acid

(c)

schiff ’s base

(d)

ketone

12.

Which one of the following will not undergo Hofmann bromamide reaction.

(a)

CH₃CONHCH₃

(b)

CH₃CH₂CONH₂

(c)

CH₃CONH₂

(d)

C₆H₅CONH₂

13.

Which one of the following reduces tollens reagent

(a)

formic acid

(b)

acetic acid

(c)

benzophenone

(d)

none of these

14.

Ethanoic acid \(\overset { P/{ Br }_{ 2 } }{ \longrightarrow } \) 2-bromoethanoic acid. This reaction is called _______.

(a)

Finkelstein reaction

(b)

Haloform reaction

(c)

Hell – Volhard – Zelinsky reaction

(d)

none of these

15.

The formation of cyanohydrin from acetone is an example of _______.

(a)

nucleophilic substitution

(b)

electrophilic substitution

(c)

electrophilic addition

(d)

Nucleophilic addition

16.

On reacting with neutral ferric chloride, phenol gives ______.

(a)

red colour

(b)

violet colour

(c)

dark green colour

(d)

no colouration.

17.

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

18.

Which one of the following is the strongest acid.

(a)

2 - nitrophenol

(b)

4 – chlorophenol

(c)

4– nitrophenol

(d)

3 – nitrophenol

19.

Match the following

a	Pure nitrogen	i	Chlorine
b	Haber process	ii	Sulphuric acid
c	Contact process	iii	Ammonia
d	Deacons Process	iv	Sodium azide (or) Barium azide

Which of the following is the correct option?

(a)

A	B	C	D
i	ii	iii	iv

(b)

A	B	C	D
ii	iv	i	iii

(c)

A	B	C	D
iii	iv	ii	i

(d)

A	B	C	D
iv	iii	ii	i

20.

Collodion is a 4% solution of which one of the following compounds in alcohol – ether mixture?

(a)

Nitroglycerine

(b)

Cellulose acetate

(c)

Glycoldinitrate

(d)

Nitrocellulose

21.

The most effective electrolyte for the coagulation of As₂S₃Sol is _______.

(a)

NaCl

(b)

Ba(NO₃)₂

(c)

K₃[Fe(CN)₆]

(d)

Al₂(SO₄)₃

22.

While charging lead storage battery _______.

(a)

PbSO₄ on cathode is reduced to Pb

(b)

PbSO₄ on anode is oxidised to PbO₂

(c)

PbSO₄ on anode is reduced to Pb

(d)

PbSO₄ on cathode is oxidised to Pb

23.

During electrolysis of molten sodium chloride, the time required to produce 0.1mole of chlorine gas using a current of 3A is _____.

(a)

55 minutes

(b)

107.2 minutes

(c)

220 minutes

(d)

330 minutes

24.

Faraday constant is defined as_______.

(a)

charge carried by 1 electron

(b)

charge carried by one mole of electrons

(c)

charge required to deposit one mole of substance

(d)

charge carried by 6.22 ×10¹⁰ electrons

25.

If the solubility product of lead iodide is 3.2 × 10^-8, its solubility will be _______.

(a)

2 × 10^-3M

(b)

4 × 10^-4M

(c)

1.6 × 10^-5M

(d)

1.8 × 10^-5M

26.

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

(a)

BF₃

(b)

PF₃

(c)

(d)

F^–

27.

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

28.

In an hexagonal crystal _______.

(a)

a=b=c,∝ =β=૪=90°

(b)

a=b=c,∝ =β=૪≠90°

(c)

a=b≠c,∝ =β=૪=90°

(d)

a=b≠c,∝ =β=90°૪=120°

29.

Which of the following is not coloured?

(a)

Mn²⁺

(b)

Zn²⁺

(c)

Cr³⁺

(d)

Cu²⁺

30.

If the initial concentration of the reactant is doubled, the time for half reaction is also doubled. Then the order of the reaction is______.

(a)

Zero

(b)

one

(c)

Fraction

(d)

none

31.

For a first order reaction, the rate constant is 6.909 min^-1the time taken for 75% conversion in minutes is _______.

(a)

\(\left( \frac { 3 }{ 2 } \right) { \log 2 }\)

(b)

\(\left( \frac { 2 }{ 3 } \right) \log2\)

(c)

\(\left( \frac { 3 }{ 2 } \right) \log\left( \frac { 3 }{ 4 } \right) \)

(d)

\(\left( \frac { 2 }{ 3 } \right) \log\left( \frac { 4 }{ 3 } \right) \)

32.

The addition of a catalyst during a chemical reaction alters which of the following quantities?

(a)

Enthalpy

(b)

Activation energy

(c)

Entropy

(d)

Internal energy

33.

The yellow colour in NaCl crystal is due to ________.

(a)

excitation of electrons in F centers

(b)

reflection of light from Cl^- ion on the surface

(c)

refraction of light from Na⁺ ion

(d)

all of the above

34.

The vacant space in bcc lattice unit cell is ________.

(a)

48%

(b)

23%

(c)

32%

(d)

26%

35.

The number of unit cells in 8 gm of an element X (atomic mass 40) which crystallizes in bcc pattern is (N_A is the Avogadro number)________.

(a)

6.023 x 10²³

(b)

6.023 x 10²²

(c)

60.23 x 10²³

(d)

\(\left( \frac { 6.023\times { 10 }^{ 23 } }{ 8\times 40 } \right) \)

36.

Which of the following is paramagnetic in nature?

(a)

[Zn(NH₃)₄]²⁺

(b)

[Co(NH₃)₆]³⁺

(c)

[Ni(H₂O)₆]²⁺

(d)

[Ni(CN)₄]^2-

37.

Which type of isomerism is exhibited by [Pt(NH₃)₂Cl₂]?

(a)

Coordination isomerism

(b)

Linkage isomerism

(c)

Optical isomerism

(d)

Geometrical isomerism

38.

A magnetic moment of 1.73BM will be shown by one among the following.

(a)

TiCl₄

(b)

[CoCl₆]^4-

(c)

[Cu(NH₃)₄]²⁺

(d)

[Ni(CN)₄]^2-

39.

Which of the following oxidation states is most common among the lanthanoids?

(a)

(b)

(c)

(d)

40.

Permanganate ion changes to ________ in acidic medium.

(a)

MnO₄²⁻

(b)

Mn²⁺

(c)

Mn³⁺

(d)

MnO₂

41.

The correct order of increasing oxidizing power in the series _______.

(a)

VO₂⁺ < Cr₂O₇^2- < MnO₄^-

(b)

Cr₂O₇^2- < VO₂⁺ < MnO₄^-

(c)

Cr₂O₇^2- < MnO₄^- < VO₂⁺

(d)

MnO₄^- < Cr₂O₇^2- < VO₂⁺

42.

Which of these is not a monomer for a high molecular mass silicone polymer?

(a)

Me₃SiCl

(b)

PhSiCl₃

(c)

MeSiCl₃

(d)

Me₂SiCl₂

43.

Most easily liquefiable gas is _______.

(a)

(b)

(c)

(d)

44.

The basicity of pyrophosphorous acid ( H₄P₂O₅) is _______.

(a)

(b)

(c)

(d)

45.

An element belongs to group 15 and 3^rdperiod of the periodic table, its electronic configuration would be_______.

(a)

1s² 2s² 2p⁴

(b)

1s² 2s² 2p³

(c)

1s² 2s² 2p⁶ 3s² 3p²

(d)

1s² 2s² 2p⁶ 3s² 3p³

46.

Carbon atoms in fullerene with formula C₆₀have _______hybridisation.

(a)

sp³ hybridised

(b)

sp hybridised

(c)

sp² hybridised

(d)

partially sp² and partially sp³ hybridised

47.

Which of the following metals has the largest abundance in the earth’s crust?

(a)

Aluminium

(b)

Calcium

(c)

Magnesium

(d)

Sodium

48.

In the electrolytic refining of copper, which one of the following is used as anode?

(a)

Pure copper

(b)

Impure copper

(c)

Carbon rod

(d)

Platinum electrode

49.

Electrochemical process is used to extract_______.

(a)

Iron

(b)

Lead

(c)

Sodium

(d)

silver

50.

Bauxite has the composition ______.

(a)

Al₂O₃

(b)

Al₂O₃.nH₂O

(c)

Fe₂O₃.2H₂O

(d)

None of these

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Answers Key:

Multiple Choice Question

50 x 1 = 50

(a)
\(\mathrm{pH}=\mathrm{pK}_{\mathrm{a}}+\log \frac{[\mathrm{salt}]}{[\mathrm{acid}]}\)

(a)
1

(a)
acetylsalicylic acid

(d)
D-Glucose

(d)
1 and 5

10.

(d)
N(CH₃)₂H>N(CH₃)H₂> N(CH₃)₃> NH₃

11.

12.

(a)
CH₃CONHCH₃

13.

14.

15.

(d)
Nucleophilic addition

16.

(b)
violet colour

17.

(d)
ethan -1, 2-diol

18.

19.

(d)

A B C D

iv iii ii i

20.

Pyroxylin(nitro cellulose)

21.

As₂S₃ is a negatively charged colloid. It will be most effectively coagulated by the cation with greater valency. i.e., Al³⁺.

22.

Charging anode:
PbSO_4(s) + 2e^- ➝ Pb_(s) + SO₄^2-_(aq)
Cathode:
PbSO_4(s) + 2H₂O_(I) ➝ PbO_2(s) + SO₄^2-_(aq) + 2e^-

23.

mass of 1 mole of CI₂ gas = 71
∴ mass of 0.1 mole of Cl₂ gas = 7.1 g mol^-1
m = Zlt
t = m/ZI
\(= \frac{7.1}{\frac{71}{2 \times 96500} \times 3}\) (2Cl^- ➝ Cl₂+ 2e^-)
\(= \frac{2 \times 96500 \times 7.1}{71 \times 3}\)
= 6433.33s = 107.2 min

24.

IF = 96500 C = charge of one mole of e^- charge of 6.022 x 10^-23 electron

25.

PbI_2(s) ⇌ Pb²⁺_(aq) + 2I^-_(aq)
K_sp = (s) (2s)²
3.2 × 10^-8 = 4s³
s = (3.2 × 10^-8/4)^1/3
= ( 8 x 10^-9)^1/3
= 2 x 10^-3 M

26.

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

27.

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.

28.

(d)
a=b≠c,∝ =β=90°૪=120°

29.

(b)
Zn²⁺

30.

t_1/2 α \(\frac{1}{[A_{0}]^{n-1}}\)...(1)
If [A₀ = 2[A₀]; then t_1/2 = 2t_1/2
2t_1/2 α \(\frac{1}{[2A_{0}]^{n-1}}\)...(2)
(2)/(1) = \(2= \frac{1}{[2A_{0}]^{n-1}} \times \frac{1}{[A_{0}]^{n-1}}\)
\(2= \frac {[2A_{0}]^{n-1}} {[A_{0}]^{n-1}}\)
\(2= \frac {1} {2}^{n-1}\)
2 = (2^-1)^n-1
2¹ = (2^-n+1)
n = 0

31.

\(k=\frac { 2.303 }{ t } \log\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
[A₀] = 100: [A] = 25
\(6.909=\frac { 2.303 }{ t } \log\frac { \left[ {100 } \right] }{ \left[ 25\right] } \)
\(t =\frac { 2.303 }{ 6.909 } \log(4)\)
\(t =\frac { 1 }{ 3 } \log(2^2)\)
\(= \left( \frac { 2 }{ 3 } \right) \log2\)

32.

A catalyst provides a new path to the reaction with low activation energy. i.e., it lowers the activation energy.

33.

(a)
excitation of electrons in F centers

34.

Packing efficiency = 68%
\(\therefore\)empty space percentage = 100 - 68 = 32%

35.

In bcc unit cell,
2 atoms = 1 unit cell
Number of atoms in 8 g of element is, Number of moles = 8g / 40 g mol^-1 = 0.2 mol
1 mole contains 6.023 x10²³ atoms
0.2 mole contains 0.2 x 6.023 x 10²³ atoms
[1 unit cell / 2 atoms] x 0.2 x 6.023 x 10²³
= 6.023 x 10²² unit cells.

36.

a) Zn²⁺ (d¹⁰ ⇒ diamagnetic)
b) Co³⁺ (d⁶ Low spain ⇒ t_2g⁶ e⁰_g ; diamagnetic)
c) Ni²⁺ (d⁸ Low spain ⇒ t_2g⁶ e²_g ; paramagnetic)
d) [Ni(CN)₄]²⁺ (dsp² ; square planar, diamagnetic)

37.

38.

Ti⁴⁺ (d⁰ ⇒ 0BM)
Co²⁺ (d⁷ spain free ⇒ t_2g⁵, e²_g;n = 3; μ = 3.9BM)
Cu²⁺ (d⁹ Low spain ⇒ t_2g⁶, e³_g; n = 1; μ = 1.732BM)
Ni²⁺ (d⁸ Low spain ⇒ t_2g⁶, e²_g;n = 2; μ = 2.44 BM)