M.C.Q [1M]

MCQ 11 Mark

Match the item given in Column I with expression given in Column II

Column I	Column II
(a) Osmotic Pressure	$p = K _{ H } \cdot \chi_{ B }$
(b) Relative lowering of vapour pressure	$\frac{\Delta P }{ P _A^o}=\chi_{ B }$
(c) Henry Law	$\Delta T _{ b }= K _{ b } \cdot m$
(d) Elevation in boiling point	p = iCRT

A
(a) (ii), (b) - (iii), (c) - (iv), (d) - (i).
B
(a) (iv), (b) - (iii), (c) - (ii), (d) - (i).
C
(a) - (iii), (b) - (i), (c) - (ii), (d) - (iv).
✓
(a) (iv), (b) - (ii), (c) - (i), (d) - (iii).

Answer

Correct option: D.

(a) (iv), (b) - (ii), (c) - (i), (d) - (iii).

(d) (a)-(iv), (b) - (ii), (c) - (i), (d) - (iii).
Explanation: (a)-(iv), (b) - (ii), (c) - (i), (d) - (iii).

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MCQ 21 Mark

In the reaction

A
Phenols are acidic in nature.
B
They can donate a proton to a stronger base
C
Cleavage of O - H bond
✓
All of these

Answer

Correct option: D.

All of these

(d) All of these
Explanation: Phenol reacts with sodium hydroxide solution to give a colourless solution containing sodium phenoxide. In this reaction, the hydrogen ion has been removed by the strongly basic hydroxide ion in the sodium hydroxide solution.

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MCQ 31 Mark

Isomers of the compound C₄H₉Br are:

A
1-Bromo-2-methylbutane and 2-Bromo-2- methylbutane
B
1- Bromobutane and 2 - Bromobutane
✓
1 - Bromobutane, 2 - Bromobutane, 1 - bromo-2-methylpropane, and 2 - bromo-2 - methylpropane
D
1-Bromo-2-methylpropane and 2 - Bromo-2-methylpropane

Answer

Correct option: C.

1 - Bromobutane, 2 - Bromobutane, 1 - bromo-2-methylpropane, and 2 - bromo-2 - methylpropane

(c) 1-Bromobutane, 2 - Bromobutane, 1- bromo-2-methylpropane, and 2-bromo-2-methylpropane
Explanation: Isomers are compounds having the same molecular formula but different structures. In the given straight-chain 4-C compounds, Br is placed at different positions but the molecular formula is same.

In the given branched 4-C compounds, there is a branching of -CH3 at carbon 2 but Br is placed at positions 1 and 2 respectively.

So, all of these are isomers since they have the same molecular formula but different structures.

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MCQ 41 Mark

Which one among the following metals of 3d series has the lowest melting point?

A
Cu
B
Fe
✓
Zn
D
Mn

Answer

Correct option: C.

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MCQ 51 Mark

Which of the following is a disaccharide?

A
Glucose
B
Cellulose
✓
Lactose
D
Starch

Answer

Correct option: C.

Lactose

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MCQ 61 Mark

Gabriel synthesis is used for the preparation of:

A
Quaternary salt
✓
Primary amines
C
Tertiary amine
D
Secondary amine

Answer

Correct option: B.

Primary amines

(b) Primary amines
Explanation: In Gabriel Phthalimide reaction, the sodium or potassium salt of phthalimide is N-alkylated with a primary alkyl halide to give the corresponding N-alkylphthalimideis for producing primary amines. This is because of the reaction of sodium or potassium salt of phthalimide with alkyl halide impure SN₂ reaction

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MCQ 71 Mark

Value of Henry's constant K_H:

A
increases with decrease in temperature.
B
remains constant.
✓
increases with increase in temperature.
D
decreases with increase in temperature.

Answer

Correct option: C.

increases with increase in temperature.

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MCQ 81 Mark

Chloromethane on treatment with excess of ammonia yields mainly

✓
Methanamine (CH₃NH₂)
B
Mixture containing all these in equal proportion
C
N-methylmethanamine (CH₃-NH-CH₃)
D
N, N-Dimethylmethanamine

Answer

Correct option: A.

Methanamine (CH₃NH₂)

(a)Methanamine (CH₃NH₂)
Explanation: CH₃Cl + NH₃ → CH₃NH₂ + HCl
Ammonia molecule is a nucleophile in nature as it has unpaired electrons. This nucleophile attacks the chloromethane CH₃Cl molecule and forms methylamine or methenamine by a nucleophilic substitution reaction mechanism. The carbon atom is partially positive in the molecule, due to the electronegativity of the halide attached which is partially negative. The electron- rich nucleophile attacks the positive ion, causing the halide ion to be separated from the molecule.

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MCQ 91 Mark

The fragrance of the aldehyde and ketone are used for perfume and similar uses depend on:

A
on its reactivity with other functional groups.
✓
size and solubility of the aldehyde and ketone molecule.
C
only solubility of aldehydes and ketones.
D
moisture of the air.

Answer

Correct option: B.

size and solubility of the aldehyde and ketone molecule.

(b) size and solubility of the aldehyde and ketone molecule.
Explanation: Size and solubility of aldehyde and ketone determine fragrance. For example, aldehyde C-10 is used in floral blends like rose, jasmine, etc. While aldehyde C-11 has a strong citrus smell and aldehyde C-16 has a strong strawberry smell.

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MCQ 101 Mark

The half-life of a reaction is halved as the initial concentration of the reactant is doubled. The order of the reaction is:

A
1
B
$0$
✓
2
D
3

Answer

Correct option: C.

(c) 2
Explanation: For 2^nd order reaction, the half-life is inversely related to the concentration of the reactant. t_1/2 for second order reaction $\alpha \frac{1}{[R]}$

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MCQ 111 Mark

When diethyl ether is heated with excess of HI, it produces :

✓
ethyl iodide
B
ethanol
C
methyl iodide
D
iodoform

Answer

Correct option: A.

ethyl iodide

(a) ethyl iodide
Explanation: ethyl iodide

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MCQ 121 Mark

Which of the following does not give silver mirror test?

A
CH₃CH₂CHO
B
HCOOH
C
CH₃CHO
✓
CH₃COCH₃

Answer

Correct option: D.

CH₃COCH₃

(d) CH₃COCH₃Explanation: CH₃COCH₃ will not give a silver mirror test (Tollens Test). Tollens test is given by aldehydes only and HCOOH is the only acid that gives tollen's test. Ketones do not give tollen's test.

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Chemistry M.C.Q [1M]

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