Chemistry Test

Result

Chemistry Test - 17

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

For synthesis of 1-butene, CH3MgI should be treated with

A
propene

B
2-chloropropene

C
allyl chloride

D
ethyl chloride

Solution
Question 2
1 / -0

Berthelot’s synthesis is used for the manufacture of

A
methane

B
ethane

C
ethylene

D
acetylene

Solution

Berthelot synthesised acetylene gas, which he named although it had been discovered earlier, by passing hydrogen through an electric arc produced with carbon poles.
Question 3
1 / -0

Allene (C₃H₄) contains

A
one double bond, one triple bond and one single bond

B
one triple and two double bonds

C
two triple and one double bonds

D
two double and four single bonds

Solution

An allene is a compound in which one carbon atom has double bonds with each of its two adjacent carbon centres. It contains two double bonds and four single bonds.
Question 4
1 / -0

C-H bond energy is about 101 kcal/mol for methane, ethane and other alkanes, but is only 77 kcal/mol for C-H bond of CH₃ in toluene. This is because

A
of inductive effect due to – CH₃ in toluene

B
of the presence of benzene ring in toluene

C
of resonance among the structures of benzyl radical in toluene

D
of aromaticity of toluene

Solution

The C- H bond-dissociation energy is about 101 kcal/mole for methane, ethane, and other alkanes, but is only 77 kcal/mole for toluene, as determined by Szware from its rate of pyrolysis and by Schissler and Stevenson by electron impact. The difference, 24 kcal/mole, can be attributed to the resonance stabilization of the benzyl radical that is produced by removing one hydrogen atom from the methyl group of toluene; this radical resonates among the several structures.
Question 5
1 / -0

Ethylene is converted to X on passing through a mixture of an acidified aqueous solution of palladium chloride and cupric chloride. Which of the following reagents readily take part in addition reaction with X?

A
Br₂

B
HBr

C
HCl

D
HCN

Solution
Question 6
1 / -0

Alkyl halides, on treatment with a suspension of Ag₂O (dry), give

A
alkanals

B
alkanols

C
alkanes

D
alkoxy alkanes

Solution
Question 7
1 / -0

Directions: The question consists of two statements: Assertion and Reason. While answering the question, you are required to choose any one of the following four responses.

Assertion: Benzyl bromide, when kept in acetone-water, produces benzyl alcohol.

Reason: The reaction follows SN²mechanism.

A
Both assertion and reason are true and reason is the correct explanation of assertion.

B
Both assertion and reason are true, but reason is not the correct explanation of assertion.

C
Assertion is true, but reason is false.

D
Both assertion and reason are false.

Solution
Question 8
1 / -0

Fluorobenzene (C₆H₅F) can be synthesised in the laboratory

A
by heating phenol with HF and KF

B
from aniline by diazotisation, followed by heating the diazonium salt with HBF₄

C
by direct fluorination of benzene with F₂gas

D
by reacting bromobenzene with NaF solution

Solution

Flurobenzene can be synthesised from aniline by diazotisation, followed by heating the diazonium salt with HBF₄.
Question 9
1 / -0

Wurtz reaction involves the reduction of alkyl halide with

A
Zn/HCl

B
HI in presence of red phosphorus

C
sodium in ether

D
Zn/Cu couple

Solution

Wurtz reaction involves the reduction of alkyl halide with sodium in ether.
Question 10
1 / -0

Directions: The following question has four choices out of which ONLY ONE is correct.

The molecular formula of chloropicrin is

A
CHCl₃NO₂

B
CCl₃NO₃

C
CCl₂NO₂

D
CCl₃NO₂

Solution

Chloropicrin, also known as PS and nitrochloroform, is a chemical compound with the structural formula Cl₃CNO₂.
Question 11
1 / -0

Which of the following is the correct order of decreasing S_N2 reactivity?

A
R₃CX > R₂CHX > RCH₂X

B
R₂CHX > R₃CX > RCH₂X

C
RCH₂X > R₃CX > R₂CHX

D
RCH₂X > R₂CHX > R₃CX

Solution

Rate of SN² reaction is based on the steric hindrance and the electron density at the carbon attached to halogen.
It follows the order: RCH₂X > R₂CHX > R₃CX
Question 12
1 / -0

Addition of HCl to vinyl chloride gives 1,1–dichloroethane because of

A
inductive effect of Cl

B
restricted rotation around the double bond

C
mesomeric effect of Cl

D
None of these

Solution

During the addition of HCl to vinyl chloride carbocation is formed as an intermediate which is stabilised by mesomeric effect of Cl^-.
Question 13
1 / -0

Which of the following reacts with phenol to give salicylaldehyde after hydrolysis?

A
Dichloro methane

B
Trichloro methane

C
Methyl chloride

D
None of these

Solution
Question 14
1 / -0

Reaction of ethyl acetate with excess of CH3MgI followed by hydrolysis gives

A
n - propyl alcohol

B
ethanal

C
propanal

D
tert-Butyl alcohol

Solution
Question 15
1 / -0

Clemmensen reduction of a ketone is carried out in the presence of

A
H₂with Pd as catalyst

B
glycol with KOH

C
LiAlH₄in ether

D
Zn-Hg with HCl

Solution

Clemmensen reduction is the reduction of carbonyl groups of aldehydes and ketones to methylene groups with amalgamated zinc and concentrated HCl.