CBSE 11TH CHEMISTRY (Test 4)



Tag: cbse 11th chemistry
Q.1
Which of the following pollutants can degrade by natural processes :
A. Vegetables
B. Nuclear waste
C. Refrigerant materials
D. Majority of chemicals
Answer : Option A
Explaination / Solution:

Vegetables have cell walls made up of cellulose which is a natural polymer and thus is bio-degradable, so they breakdown by natural processes.

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Q.2
Carbon monoxide is poisonous to human beings because :
A. Results in tears and redness
B. Acute respiratory disease
C. It binds to haemoglobin and eventually produces oxygen deficiency
D. They are carcinogenic
Answer : Option C
Explaination / Solution:

CO has more affinity to bind to Hb than oxygen. So it blocks the binding of oxygen to Hb causing deficiency of it and can lead to death.

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Q.3
Recycling of materials and energy will lead to :
A. Increase in green house gases
B. Increas in the trapped solar energy
C. Decrease in environmental pollution
D. Increase in soil pollution
Answer : Option C
Explaination / Solution:

Recycling of materials and energy will lead to decrease in environmental pollution as amount of waste material will be lesser and so lesser pollution will be caused.

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Q.4
Sulphur dioxide levels can be reduced by using :
A. More efficient car engines
B. Static electricity to attract it in factory chimneys
C. Low sulphur fuels
D. Catalytic converters
Answer : Option C
Explaination / Solution:

Sulphur dioxide levels can be reduced by using Low sulphur fuels so that less amount of SO2 is produced from them

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Q.5
Deforestation is responsible for:
A. Diversification
B. Desertification
C. Salinisation
D. Eutrophication
Answer : Option B
Explaination / Solution:

Deforestation is responsible for desertification

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Q.6
Which of these is not a characteristic of aromatic Hydrocarbons?
A. carbon atoms form a closed chain or ring
B. carbon atoms form a an open chain
C. they may contain double bonds
D. they are special type of cyclic compounds
Answer : Option B
Explaination / Solution:

aromatic hydrocarbon are not open chained. They are ring structures.they contain one or more benzene rings either fused or isolated in their molecules.

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Q.7

One of the methods of preparing ethylene is given below.This is an example of _______ reaction


A. Rearrangement reaction
B. Elimination reaction
C. Substitution reaction
D. Addition reaction
Answer : Option B
Explaination / Solution:

Dehydration of alcohols in the presence of alc. KOH to form an alkene is an example of elimination reaction.

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Q.8
Which of the following method is not a synthetic method for production of Benzene?
A. isolation from coal tar
B. Cyclic polymerization of ethyne
C. By reduction of phenol
D. Decarboxylation of aromatic acids
Answer : Option A
Explaination / Solution:

Since isolation of benzene from coal tar involves separation of benzene from other components through a physical operation "fractional distillation" , it is NOT a synthetic method for production of benzene.

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Q.9
Arrange the following alkyl halides in decreasing order of the rate of  elimination reaction with alcoholic KOH

A. C > B > A
B. A > C > B
C. B > C > A
D. A > B > C
Answer : Option B
Explaination / Solution:

A more substituted alkene is preferred in accordance with the Saytzeff's rule.Hence the order.

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Q.10
One mole of a symmetrical alkene on ozonolysis, and subsequent treatment with ( Zn / H2 O ) gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is ---------.?
A. 1-butene
B. Propene
C. Ethene
D. 2-butene
Answer : Option D
Explaination / Solution:

Ozonolysis of alkenes involves the addition of ozone molecule to alkene to form an unstable ozonide , and then cleavage of the ozonide by  to smaller molecules .  

2- butene is a symmetrical alkene , which on ozonolysis yields two moles of   having molecular mass   of 44 u. as per reaction given   below,

 

 


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