M.C.Q (1 Marks)

MCQ 11 Mark

Aniline reacts with sodium nitrite and hydrochloric acid at 273-278K to give:

A
Chlorobenzene
✓
Benzene diazonium chloride
C
o-chloroaniline
D
Benzene

Answer

Correct option: B.

Benzene diazonium chloride

(b) Benzene diazonium chloride
Explanation: Benzene diazonium chloride

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MCQ 21 Mark

The reaction $C _2 H _5 ONa + C _2 H _5 I \rightarrow C _2 H _5 OC _2 H _5+ NaI$ is known as:

✓
Williamson's synthesis
B
Grignard's synthesis
C
Wurtz's synthesis
D
Kolbe's synthesis

Answer

Correct option: A.

Williamson's synthesis

(a) Williamson's synthesis Explanation: Williamson's synthesis: When an alkyl halide reacts with sodium alkoxide, ether is formed. This reaction is known as Williamson's synthesis. The reaction generally follows the $S_N 2$ mechanism for primary alcohols.
$ R-X+R^{\prime}-\ddot{O} \stackrel{+}{N} a \rightarrow R-\ddot{O}-R^{\prime}+N a X $
Williamson's synthesis

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MCQ 31 Mark

Iodoform test is given by

A
Ethanoic acid
B
Pentan-3-one
C
Methoxymethane
✓
Pentan-2-one

Answer

Correct option: D.

Pentan-2-one

(d) Pentan-2-one
Explanation: Pentan-2-one

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MCQ 41 Mark

Rate of reaction does not remain constant throughout because

A
The density of reactants keep on changing
✓
Concentration of reactants keep on changing
C
Volume of reactants keep on changing
D
Temperature of reactants keep on changing

Answer

Correct option: B.

Concentration of reactants keep on changing

(b) Concentration of reactants keep on changing.
Explanation: Rate of reaction is dependent on the concentration of reactants if the concentration of reactants change then the rate of reaction become non-uniform.

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MCQ 51 Mark

Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?

A
They retain metallic conductivity.
B
They have high melting points in comparison to pure metals.
✓
They are chemically very reactive.
D
They are very hard.

Answer

Correct option: C.

They are chemically very reactive.

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MCQ 61 Mark

Which of the following compounds has the highest boiling points?

A
$CH _3 CH _2 CH _2 Cl$
✓
$CH _3 CH _2 CH _2 CH _2 Cl$
C
$\left( CH _3\right)_3 Cl$
D
$CH _3 CH \left( CH _3\right) CH _2 Cl$

Answer

Correct option: B.

$CH _3 CH _2 CH _2 CH _2 Cl$

The forces of attraction between the molecules of a compound get stronger as they get bigger in size and have more electrons. Also, for a straight-chain compound, the points of interaction between the molecules are more than for a branched compound having the same molecular formula. Thus $CH_3CH_2CH_2CH_2Cl$ has the highest melting point since it is the longest chain compound among the given options.

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MCQ 71 Mark

Match the types of solutions given Column I to the examples given in Column II.

Column I	Column II
(a) Solution of gas in gas	(i) Brass
(b) Solution of solid in solid	(ii) Air
(c) Solution of liquid in gas	(iii) Zinc amalgam
(d) Solution of liquid in solid	(iv) Chloroform in Nitrogen

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

Answer

Correct option: D.

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

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

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MCQ 81 Mark

A reaction follows second order kinetics. How is the rate of reaction affected if the concentration of the reactant is reduced to half? Choose the correct value from the following:

A
four times
✓
$\frac{1}{4}$ of the original value
C
three times
D
eight times

Answer

Correct option: B.

$\frac{1}{4}$ of the original value

(b) $\frac{1}{4}$ of the original value
Explanation: $\frac{1}{4}$ of the original value

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MCQ 91 Mark

Give the products of the reaction
$PhC \equiv CMe \xrightarrow{H_3 O^{+}, Hg^{2+}} ?$

A
$PhCH_2CH_2CHO$
B
$PhCOCH_2CH_3$
C
$PhCOCOMe$
D
$PhCH_2COCH_3$

Answer

Hydration of given alkyne will occur according to Markovnikoff's rule leading to the formation of enol which will tautomerise to give keto form.
The general reaction of alkyne hydrations shown below$:$

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MCQ 101 Mark

The major product of acid catalysed dehydration of 1-methylcyclohexanol is:

A
1-methylenecyclohexane
✓
1-methylcyclohexene
C
1-methylcyclohexane
D
1-cyclohexylmethanol

Answer

Correct option: B.

1-methylcyclohexene

(b) 1-methylcyclohexene
Explanation: According to Saytzeff rule, i.e., highly substituted alkene is major product. Here dehydration reaction takes place, alkene is formed due to the removal of a water molecule