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Class 11 Chemistry Mcqs

Q:

Identify the non-toxic and green solvent.

A) Liquified carbondioxide B) Benzene
C) Carbon tetrachloride D) Toluene
 
Answer & Explanation Answer: A) Liquified carbondioxide

Explanation: When compared to conventional solvents, liquified CO? leaves a lower amount of residue. It is also a non-toxic and attractive solvent for temperature-sensitive materials.

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97
Q:

Which of the following is a green solvent used for bleaching clothes?

A) Hydrogen peroxide B) Tetrachloroethene
C) Benzene D) Toluene
 
Answer & Explanation Answer: A) Hydrogen peroxide

Explanation: Hydrogen peroxide can easily breakdown into water and oxygen. It is a good oxidizing agent and a strong bleaching agent. Use of H?O? gives better results and makes use of a lesser amount of water.

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Sub Category: Class 11 Chemistry Mcqs

96
Q:

Replacement of liquid CO? by halogenated solvent will result in less harm to groundwater.

A) True B) False
 
Answer & Explanation Answer: B) False

Explanation: Halogenated solvents contaminate groundwater. Whereas liquified CO? leaves a lower amount of residue. It is also a non-toxic and attractive solvent for temperature-sensitive materials.

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58
Q:

Which of the following gas was traditionally used to bleach paper?

A) Sulfur B) Carbon dioxide
C) Chlorine D) Fluorine
 
Answer & Explanation Answer: C) Chlorine

Explanation: Chlorine gas was used to bleach paper. It has good oxidizing properties. Nowadays H?O? with a suitable catalyst is used for bleaching purposes as it does not contaminate groundwater.

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91
Q:

Green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Identify the technique used in this area.

A) Bioamplification B) Polymer manufacturing
C) Pesticide synthesis D) Use of sunlight and Microwave-assisted reaction
 
Answer & Explanation Answer: D) Use of sunlight and Microwave-assisted reaction

Explanation: Photochemical reaction occurs when light energy gets absorbed by a substances’ molecule. It is a green route as no byproduct will be formed. Vitamin D3 synthesis is assisted by a photochemical reaction.

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55
Q:

Which of the following is not a principle of Green Chemistry?

A) Green solvents and auxiliaries B) Use of renewable feedstock
C) Hazardous chemical synthesis D) Design for energy efficiency
 
Answer & Explanation Answer: C) Hazardous chemical synthesis

Explanation: Synthetic methods should avoid using or generating substances toxic to humans and/or the environment. Hence less hazardous chemical synthesis is an important principle.

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98
Q:

Name the conventional solvent that was used for dry cleaning purposes which later confirmed to be a suspected carcinogen.

A) Supercritical CO? B) Phenanthrene
C) Tetrachloroethene D) Benzene aldehyde
 
Answer & Explanation Answer: C) Tetrachloroethene

Explanation: Tetrachloroethene was used as a solvent for dry cleaning purposes. It is a suspected carcinogen and groundwater contaminant. It is replaced by greener solvent like supercritical CO?.

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Sub Category: Class 11 Chemistry Mcqs

48
Q:

Which of the following is a greener route to produce ethanal commercially?

A) Catalytic cracking of ethanol B) Oxidation of ethene with an ionic catalyst
C) Steam reforming of methanol D) Dehydrogenation of ethylene
 
Answer & Explanation Answer: B) Oxidation of ethene with an ionic catalyst

Explanation: Ethanal can be prepared by oxidation of ethene, in the presence of an ionic catalyst in an aqueous medium. This is a greener method and gives 90% of yield.

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