M.C.Q (1 Marks)

MCQ 11 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

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MCQ 21 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 31 Mark

Which of the following does not give silver mirror test?

A
$CH_3CH_2CHO$
B
$HCOOH$
C
$CH_3CHO$
✓
$CH_3COCH_3$

Answer

Correct option: D.

$CH_3COCH_3$

$: CH_3COCH_3$ 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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MCQ 41 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.

$2$

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MCQ 51 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 61 Mark

Isomers of the compound $\ce{C_4H_9Br}$ 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

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 $-CH_3$ 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 71 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 81 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.

Value of henry constant increases with increase in temperature.

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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

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 111 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 121 Mark

Chloromethane on treatment with excess of ammonia yields mainly

A
Methanamine $\ce{(CH_3NH_2)}$
B
Mixture containing all these in equal proportion
C
$N-$methylmethanamine $\ce{(CH_3-NH-CH_3)}$
✓
$N, N-$Dimethylmethanamine

Answer

Correct option: D.

$N, N-$Dimethylmethanamine

$\ce{CH_3Cl + NH_3} \rightarrow \ce{CH_3NH_2 + HCl}$ Ammonia molecule is a nucleophile in nature as it has unpaired electrons. This nucleophile attacks the chloromethane $\ce{CH_3Cl}$ 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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Chemistry M.C.Q (1 Marks)

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