Tag: polyhalogen compounds

Questions Related to polyhalogen compounds

Acidity of fluoroform (I), bromoform (II), iodoform (III) and chloroform (IV) in decreasing order is as follows:

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. I> II> III> IV

  2. IV> III> II> I

  3. IV> I> II> III

  4. IV> I> III> II

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Correct Option: C

Which of the following is used in paint removing ?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. $CHCl _{3}$

  2. $CH _{2}Cl _{2}$

  3. $CCl _{4}$

  4. $CH _{3}Cl$

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Correct Option: B
Explanation:

$CHCl _3$ is used as solvent and as an anaesthetic.

$CCl _4$ is used as a fire extinguisher.
$CH _2Cl _2$ is used as paint removing.
$CH _3Cl$ is used as a refrigerant.

Hence, the correct option is B.

Carbon tetrachloride is inflammable. 

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. True

  2. False

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Correct Option: B

Chocolates and fatty foods containing butter or oil sometimes leave stains on clothes that are difficult to remove. They can be removed by:

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. a solution of salt in water

  2. tetrachloroethylene

  3. water

  4. alcohol

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Correct Option: B
Explanation:

Chocolates and food strains can be removed by tetrachloroethylene. It is a colourless liquid widely used for cleaning of fabrics and therefore called 'Dry-Cleaning fluid'.

Dehydrohalogenation of alkyl halides is a common preparation method of:

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. alkenes

  2. alkanes

  3. haloalkenes

  4. both A and B

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Correct Option: A
Explanation:

Dehydrohalogenation is an organic reaction in which alkyl halide when boiled with alcoholic alkali gives corresponding alkene. It is known as elimination reaction.

Alkaline hydrolysis of 1,1,1-trichloro derivative (A) of an alkane gives a molecule (B) which produces red coloration with aqueous ${ FeCl } _{ 3 }$. The compound (A) is ?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. ${ CH } _{ 3 }{ CH } _{ 2 }{ CCl } _{ 3 }$

  2. ${ CH } _{ 3 }{ CCl } _{ 3 }$

  3. ${ CH }{ Cl } _{ 3 }$

  4. None of these

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Correct Option: B
Explanation:
Alkaline hydrolysis of a trichloro derivative will give a carboxylic acid. The carboxylic acid that gives red colouration with aqueous $FeCl _{3}$ is acetic acid $CH _{3}COOH$. Hence, the compound  A is $CH _{3}CCl _{3}$.