Chemistry Test

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Chemistry Test - 28

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Weekly Quiz Competition

Question 1
1 / -0

\(C H_{4}+C l_{2} \stackrel{hv}{\longrightarrow} C H_{3} C l+H C l\)

The above shown reaction is an example of-

A
a free radical substitution reaction

B
an electrophilic substitution reaction

C
a nucleophilic substitution reaction

D
a nucleophilic addition reaction

Solution

In organic chemistry, we encounter with various types of substitution reactions. One of them is a free radical substitution reaction.

Example: Halogenation of methane

\(C H_{4}+C l_{2} \stackrel{h \nu}{\longrightarrow} C H_{3} C l+H C l\)
Hence, the correct option is (A)
Question 2
1 / -0

Number of hyperconjugable hydrogen in this molecule are :

A
1

B
2

C
3

D
4

Solution

In this structure, only \(2-H\) of \(C H_{2}-\) group takes part in hyperconjugation.
Hence, the correct option is (B)
Question 3
1 / -0

Largest difference in radii is found in which of the following pair?

A
Li,Na

B
Na,K

C
K,Rb

D
Rb,Cs

Solution

Radii of atoms increase as we go down the group due to the addition of extra energy shell. The nuclear charge also increases on moving down the group but the influence of addition of energy shell predominates. This predomination is larger in case when we move from Na to K among all the options given.

Hence, option B is correct.
Question 4
1 / -0

The correct boiling point order of Li,Na,K,Rb is:

A
Li>K>Na>Rb

B
Na>Li>K>Rb

C
Li>Na>K>Rb

D
Rb>Na>K>Li

Solution

The correct boiling point order is Li(1615K)>Na(1156K)>K(1032K)>Rb(961K)

As the atomic number increases, the van der Waals forces of attraction increases and the boiling point decreases.
Hence, the correct option is (C)
Question 5
1 / -0

During preparation of soap, sodium is used as:

A
precipitate the soap

B
dehydration of soap

C
as a catalyst

D
for smoothness of soap

Solution

NaCl is used to precipitate out all the soap from from solution because NaCl reduces the solubility of soap which causes its precipitation.

Hence, the correct option is (A)
Question 6
1 / -0

Which mineral is neccessary for blood clotting?

A
Calcium

B
Magnese

C
Phosphorus

D
Iron

Solution

Calcium plays an important role in coagulation of blood (blood clotting). Increased concentration of calcium in the platelets helps in activating various proteins important for blood clotting and thus, results in the formation of a blood clot. It helps in the binding of clotting enzymes to phospholipids in platelets and tissue and accelerate the reaction.

So, the correct answer is option A.
Question 7
1 / -0

Which of the following is/are correct statement(s) ?

(I) Ca²⁺ions are important in blood clotting.

(II) Ca₃(PO₄)₂ is a part of bones.

(III) 3Ca₃(PO₄).CaF₂ is a part of enamel of teeth.

A
(I) and (II)

B
(II) and (III)

C
(I) and (III)

D
(I), (II) and (III)

Solution

All are correct statements.

(I) Ca²⁺ ions are important in blood clotting and muscle contraction. Low level of Ca²⁺ ions increases blood clotting time.

(II) Calcium phosphate Ca₃(PO₄)₂is a part of bones. Calcium deficiency causes osteoporosis where the bones becomes soft due to reduced bone mineral density leading to easy fractures.

(III) 3Ca₃(PO₄)⋅CaF₂ is a part of enamel of teeth
Hence, the correct option is (D)
Question 8
1 / -0

The homologue of ethyne is :

A
C₂H₂

B
C₂H₆

C
C₃H₈

D
C₃H₄

Solution

A homologue is a compound belonging to a series of compounds differing from each other by a repeating unit, such as a methylene bridge −CH₂ group.

For ethyne C₂H₂, homologue will be C₃H₄.
Hence, the correct option is (D)
Question 9
1 / -0

Which of the following compounds has −OH as a functional group?

A
Butanone

B
Butanol

C
Butanoic acid

D
Butanal

Solution

In Butanone, the functional group is −C=O.

In Butanoic acid, the functional group is −COOH.

In Butanal, the functional group is −CHO.

In Butanol, the functional group is −OH.
Hence, the correct option is (B)
Question 10
1 / -0

The metal that produces red-violet colour in the non-luminous flame is:

A
Ba

B
Ag

C
Rb

D
Pb

Solution

Alkali metals and their salts impart characteristic colour to flame. the reason for flame colouration is that the energy of the flame causes an excitation of the outermost electrons which when return to their original position give out the energy absorbed in the visible region.Thus,Rb gives red-violet colour to the flame.
Hence, the correct option is (C)

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Chemistry Test - 28

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Chemistry Test - 28

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Question 1

a free radical substitution reaction

an electrophilic substitution reaction

a nucleophilic substitution reaction

a nucleophilic addition reaction

Solution

Question 2

1

2

3

4

Solution

Question 3

Li,Na

Na,K

K,Rb

Rb,Cs

Solution

Question 4

Li>K>Na>Rb

Na>Li>K>Rb

Li>Na>K>Rb

Rb>Na>K>Li

Solution

Question 5

precipitate the soap

dehydration of soap

as a catalyst

for smoothness of soap

Solution

Question 6

Calcium

Magnese

Phosphorus

Iron

Solution

Question 7

(I) and (II)

(II) and (III)

(I) and (III)

(I), (II) and (III)

Solution

Question 8

C2H2

C2H6

C3H8

C3H4

Solution

Question 9

Butanone

Butanol

Butanoic acid

Butanal

Solution

Question 10

Ba

Ag

Rb

Pb

Solution

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C₂H₂

C₂H₆

C₃H₈

C₃H₄