Question Set A

Tamilnadu12th Standard Chemistry Ionic Equilibrium Important Questions Study Material - QB365

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Questions:

Multiple Choice Question

50 x 1 = 50

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

The solubility of BaSO₄ in water is 2.42 × 10^-3gL^-1 at 298K. The value of its solubility product(K_sp) will be (Given molar mass of BaSO₄ =233g mol^-1)

(a)

1.08 × 10^-14mol²L^-2

(b)

1.08 × 10^-12mol²L^-2

(c)

1.08 × 10^-10mol²L^-2

(d)

1.08 × 10^-8mol²L^-2

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

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

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

(a)

BF₃

(b)

PF₃

(c)

CF₄

(d)

SiF₄

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

(a)

BF₃

(b)

PF₃

(c)

(d)

F^–

The number of electrons that have a total charge of 9650 coulombs is_______.

(a)

6.22 ×10²³

(b)

6.022 ×10²⁴

(c)

6.022 ×10²²

(d)

6.022 ×10⁻³⁴

The molar conductivity of a 0.5 mol dm^-3 solution of AgNO₃ with electrolytic conductivity of 5.76 ×10⁻³ S cm⁻¹at 298 K is______.

(a)

2.88 S cm²mol^-1

(b)

11.52 S cm²mol^-1

(c)

0.086 S cm²mol^-1

(d)

28.8 S cm²mol^-1

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

10.

Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because _______.

(a)

Zinc is lighter than iron

(b)

Zinc has lower melting point than iron

(c)

Zinc has lower negative electrode potential than iron

(d)

Zinc has higher negative electrode potential than iron

11.

The equivalent conductance of M/36 solution of a weak monobasic acid is 6 mho cm² equivalent^-1 and at infinite dilution is 400 mho cm² equivalent^-1. The dissociation constant of this acid is ______.

(a)

1.25 x 10⁻⁶

(b)

6.25 x 10^-6

(c)

1.25 x 10⁻⁴

(d)

6.25 x 10 ^-5

12.

Conductivity of a saturated solution of a sparingly soluble salt AB (1:1 electrolyte) at 298K is 1.85 ×10⁻⁵ S m⁻¹. Solubility product of the salt AB at 298K (Λ^o_m)_AB = 14 ×10⁻³S m² mol⁻¹.

(a)

5.7 x 10^-12

(b)

1.32 x 10⁻¹²

(c)

7.5 x 10⁻¹²

(d)

1.74 x 10^-12

13.

A certain current liberated 0.504gm of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution ______.

(a)

31.75

(b)

15.8

(c)

7.5

(d)

63.5

14.

Which of the following is incorrect for physisorption?

(a)

reversible

(b)

increases with increase in temperature

(c)

low heat of adsorption

(d)

increases with increase in surface area

15.

Statement : To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified?

(a)

It is not true, ferric chloride is a poison.

(b)

It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol

(c)

It is not true; ferric chloride is ionic and gets into the blood stream.

(d)

It is true, coagulation takes place because of formation of negatively charged sol with Cl^-.

16.

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

17.

Which one of the is not a surfactant?

(a)

CH₃ -(CH₂)₁₅ -N⁺ -(CH₃)₂ CH₂Br

(b)

CH₃ -(CH₂)₁₅ -NH₂

(c)

CH₃ -(- CH₂- )-₁₆CH₂ OSO₂^- Na⁺

(d)

OHC-(CH₂)₁₄ -CH₂ -COO^- Na⁺

18.

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

19.

The coagulation values in millimoles per litre of the electrolytes used for the coagulation of As₂S₃ are given below
(I) (NaCl) = 52
(II) ((BaCl₂) = 0.69
(III) (MgSO₄) = 0.22
The correct order of their coagulating power is ________.

(a)

III > II > I

(b)

I > II > III

(c)

I > III > II

(d)

II > III > I

20.

If x is the amount of adsorb ate and m is the amount of adsorbent, which of the following relations is not related to adsorption process?

(a)

x/m = f(P) at constant T

(b)

x/m = f(T) at constant P

(c)

P = f(T) at constant x/m

(d)

x/m = PT

21.

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

22.

Which one of the following is the strongest acid.

(a)

2 - nitrophenol

(b)

4 – chlorophenol

(c)

4– nitrophenol

(d)

3 – nitrophenol

23.

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

(a)

Dichlo methane

(b)

trichloroethane

(c)

trichloro methane

(d)

CO₂

24.

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

25.

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

26.

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

(a)

methanoic acid

(b)

Glyoxal

(c)

methanol

(d)

CO₂

27.

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

28.

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

29.

Williamson synthesis of preparing dimethyl ether is a / an ______.

(a)

SN¹ reactions

(b)

SN² reaction

(c)

electrophilic addition

(d)

electrophilic substitution

30.

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

(a)

C₆H₅COOH

(b)

C₆H₅COCH₃

(c)

C₆H₅COC₆H₅

(d)

C₆H₅- OH

31.

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

(a)

nucleophilic substitution

(b)

electrophilic substitution

(c)

electrophilic addition

(d)

Nucleophilic addition

32.

\({ CH }_{ 2 }={ CH }_{ 2 }\overset { i){ O }_{ 3 } }{ \underset { zn/{ H }_{ 2 }O }{ \longrightarrow } } X\overset { { NH }_{ 3 } }{ \longrightarrow } Y \ 'Y'\) is _______.

(a)

Formaldelyde

(b)

di acetone ammonia

(c)

hexamethylene tetraamine

(d)

oxime

33.

Benzoic acid \(\overset { i){ NH }_{ 3 } }{ \underset { ii)\Delta }{ \longrightarrow } } A\overset { NaOBr }{ \longrightarrow } B\overset { NaN{ O }_{ 2 }/HCl }{ \longrightarrow } \) C 'C' is ______.

(a)

anilinium chloride

(b)

O – nitro aniline

(c)

benzene diazonium chloride

(d)

m– nitro benzoic acid

34.

Which one of the following reduces tollens reagent

(a)

formic acid

(b)

acetic acid

(c)

benzophenone

(d)

none of these

35.

In which case chiral carbon is not generated by reaction with HCN?

(a)

(b)

(c)

(d)

36.

The method by which aniline cannot be prepared is _________.

(a)

degradation of benzamide with Br₂ / NaOH

(b)

potassium salt of phthalimide treated with chlorobenzene followed by hydrolysis with aqueous NaOH solution.

(c)

reduction of Nitrobenzene with LiAlH₄

(d)

reduction of nitrobenzene by Sn / HCl

37.

Which one of the following nitro compounds does not react with nitrous acid.

(a)

CH₃ -CH₂ -CH₂ -NO₂

(b)

(CH₃)₂ CH - CH₂NO₂

(c)

(CH₃)₃C NO₂

(d)

\({ CH }_{ 3 }-\underset { \overset { || }{ O } }{ C } -\underset { \overset { || }{ { CH }_{ 3 } } }{ CH } -{ NO }_{ 2 }\)

38.

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

(a)

carboxylic acid

(b)

aromatic acid

(c)

schiff ’s base

(d)

ketone

39.

Nitrobenzene on reaction with Con HNO₃ / H₂SO₄ at 80-100^oC forms which one of the following products?

(a)

1,4 – dinitrobenzene

(b)

2,4,6 – tirnitrobenzene

(c)

1,2 – dinitrobenzene

(d)

1,3 – dinitrobenzene

40.

Which of the following amines does not undergo acetylation?

(a)

t – butylamine

(b)

ethylamine

(c)

diethylamine

(d)

triethylamine

41.

Which one of the following rotates the plane polarized light towards left?

(a)

D(+) Glucose

(b)

L(+) Glucose

(c)

D(-) Fructose

(d)

D(+) Galactose

42.

Which one given below is a non-reducing sugar?

(a)

Glucose

(b)

Sucrose

(c)

maltose

(d)

Lactose

43.

In a protein, various amino acids linked together by ______.

(a)

Peptide bond

(b)

Dative bond

(c)

\(\alpha\) - Glycosidic bond

(d)

\(\beta\) - Glycosidic bond

44.

In aqueous solution of amino acids mostly exists in ______.

(a)

NH₂-CH(R)-COOH

(b)

NH₂-CH(R)-COO^-

(c)

H₃N⁺-CH(R)-COOH

(d)

H₃N⁺-CH(R)-COO^-

45.

The pyrimidine bases present in DNA are ______.

(a)

Cytosine and Adenine

(b)

Cytosine and Guanine

(c)

Cytosine and Thiamine

(d)

Cytosine and Uracil

46.

The secondary structure of a protein refers to ______.

(a)

fixed configuration of the polypeptide backbone

(b)

hydrophobic interaction

(c)

sequence of α-amino acids

(d)

\(\alpha-\)helical backbone.

47.

Which of the following is an analgesic?

(a)

Streptomycin

(b)

Chloromycetin

(c)

Asprin

(d)

Penicillin

48.

Aspirin is a/an _______.

(a)

acetylsalicylic acid

(b)

benzoyl salicylic acid

(c)

chlorobenzoic acid

(d)

anthranilic acid

49.

Which of the following is a co-polymer?

(a)

Orlon

(b)

PVC

(c)

Teflon

(d)

PHBV

50.

The polymer used in making blankets (artificial wool) is _______.

(a)

polystyrene

(b)

PAN

(c)

polyester

(d)

polythene

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Answers Key:

Multiple Choice Question

50 x 1 = 50

\(\mathrm{Ag}_{2} \mathrm{C_2O_4} \rightleftharpoons 2 \mathrm{Ag}_{}^{+}+\mathrm{C_2O}_{4{}}^{2-}\)
\(\left[\mathrm{Ag}^{+}\right]=2 .24 \) ×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

BaSO₄ ⇌ Ba²⁺ + SO₄^2-
K_sp = (s) (s)
K_sp = (s)²
= (2.42 × 10^-3gL^-1)²
\(=\frac{2.42 \times 10^{-3} gL^{-1}}{233 \text{ g mol}^{-1}}\)
= (0.01038 x 10^-3)²
= (1.038 x x 10^-5)²
= 1.077 x 10^-10
= 1.08 × 10^-10mol²L^-2

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

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.

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

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

Λ = k/W x 10⁻³ mol⁻¹ dm³
\(=\frac{ 5.76 \times 10^{−3} S cm^{−1} \times 10^{−3}}{0.5} = mol^{-1} dm^{3}\)
\(=\frac{ 5.76 \times 10^{−3} S cm^{−1} \times 10^{−3}}{0.5}\) S cm^-1 mol⁻¹ dm³
= 11.52 S cm²mol^-1

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

10.

E^o_Zn²⁺[Zn]= 0.76V and E^o_Fe²⁺[Fe]= -0.44V
Zinc has higher negative electrode potential than iron, iron cannot be coated on zinc

11.

α = Λ/Λ^o
= 6/400
K_a = α²C
\(= \frac{6}{400} \times \frac{6}{400} \times \frac{1}{36}\)
= 6.25 x 10^-6

12.

For 1:1 electrolyte K_sp = S²
\(=[\frac{ K \times 10^{-3}}{Λ^o}]^2\)
\(=[\frac{1.85 \times 10^{-5} \times 10^{-3}}{14 \times 10^{-3}}]^2\)
= (0.1321 x 10^-3)²
= 0.01745 x 1010^-10
= 1.74 x 10^-12

13.

\(\frac{m_{1}}{m_{2}} = \frac{E_{1}}{E_{2}} \)
\(\frac{0.504}{m_{2}} = \frac{1.008}{31.77} \)
m₂ = 15.885 g

14.

The incorrect statement is option (n)
Physisorption is an exothermic process. Hence increases in temperature decreases the Physisorption

15.