Tag: polyhalogen compounds

Questions Related to polyhalogen compounds

Which of the following statements is not correct?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. DDT and BHC are not good insecticides because they are highly soluble in water.

  2. DDT and BHC are not good insecticides because they are absorbed by the soil and contaminate root corps.

  3. Aldrin is not a good insecticide because it is not biodegradable.

  4. All of the above are incorrect.

Show answer
Correct Option: A
Explanation:

DDT and BHC 

both are good insecticides
since highly soluble in coater.

Match the column I with column II.

Columns I  Columns II 
A Carbon tetrachloride  i Paint remover 
B Methylene chloride  ii Refrigerators and air conditioners 
C DDT iii Fire extinguisher 
D Freons iv Non biodegradable insectiside 
polyhalogen compounds haloalkanes and haloarenes chemistry

  1. A=(ii), (B)=(iii), (C)=(i), (D)=(iv)

  2. A=(i), (B)=(ii), (C)=(iii), (D)=(iv)

  3. A=(iv), (B)=(iii), (C)=(ii), (D)=(i)

  4. A=(iii), (B)=(i), (C)=(iv), (D)=(ii)

Show answer
Correct Option: D
Explanation:

A) Carbon tetra-chloride is colorless, non inflammable and is used as a fire extinguisher. 

B) Methylene chloride is used as a paint remover. 
C) DDT is the chlorinated organic and non biodegradable insecticide. 
D) Freons are produced for aerosol propellants, refrigerators and air conditioners. 

0.0852 g of an organic halide (A) when dissolved in 2.0 g of camphor, the melting point of the mixture was found to be $167^{\circ}$C. Compound (A) when heated with sodium gives a gas (B). 280 mL of gas (B) at STP weighs 0.375g. What would be 'A' in the whole process? $K _f$ for camphor = 40, m.pt. of camphor = $179^{\circ}$C.

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. $C _2H _5Br$

  2. $CH _3I$

  3. $(CH _3) _2CHI$

  4. $C _3H _7Br$

Show answer
Correct Option: B
Explanation:

$\delta$=179-167=12, w=0.0852g, W=2g,Kf= 40 
Moleculer weight of (A)
=$\dfrac{1000\times{Kf}\times{w} }{\delta{T}\times {W}}$
=$\dfrac{1000\times{40}\times{0.0852} }{\delta{12}\times {2}}$
=142
(A) undergoes wortz reaction to form (B) i.e
$(A)\rightarrow{Na} (B)+NaX$
(B) is an alkane say $C _nH _2n+2$
$\therefore$ 280 mL of (B) weighs 0.375 g at NTP
$\therefore$ 22400 mL of (B) weighs 
=$\dfrac{0.375\times{22400}}{280}$
=30 g at NTP
M.wt of (B)=30, 12n+2n+2=30,n=2
Thus (B) is ethane and therefore (A) is $CH _3X$
The m.wt of $CH _3X$=142
At.wt of X=127
$\therefore$ is iodine 
Therefore alkyl halide is $CH _3I$.
This reaction is 
2$CH _3I\xrightarrow[Na]{ether} C _2h _6$
(A)                         (B)

Breathing about 900 parts this substance per million parts of air for a short time cause dizziness heart & fatigue headache is-

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. Methylene choride

  2. Chloroform

  3. Iodoform

  4. Tetra chlorometane

Show answer
Correct Option: B

Chloropicrin is ______.

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. picric derivative

  2. nitrochloroform

  3. nitromethane

  4. nitroethyl chloride

Show answer
Correct Option: C

Which of the following is used for metal cleaning and finishing?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. $CHCl _{3}$

  2. $CHI _{3}$

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

  4. $C _{6}H _{6}$

Show answer
Correct Option: C
Explanation:

Chloroform is used as solvent and as anaesthetic.
$CHI _3$ is used as antiseptic.
$CH _2Cl _2$ is used for metal cleaning and finishing.
$C _6H _6$ is used for printing and lithography, paint, rubber, dry cleaning, adhesives and coatings, detergents.

Consider the following reaction $C _2H _5I \xrightarrow[x]{\triangle} $ (Pleasant smelling liquid) X is?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. Sodium

  2. Dry silver oxide

  3. Ethyl chloride

  4. Dry silver powder

Show answer
Correct Option: B
Explanation:

Since, the product is a pleasent smelling liquid, it must be an ether. $C _2H _5I$ forms diethyl ether on reaction with dry silver oxide.

Hence $X$ is an dry silver oxide.

What is not a polyhalogen?

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. Methyl chloride

  2. Dichloro methane

  3. Chloroform

  4. Carbon tetrachloride

Show answer
Correct Option: A

Which of the following compounds will give haloform test?
(i) $CH _3COCH _2l$
(ii) $CH _3CHCl-CH _3$
(iii) $C _6H _5COCH _3$
(iv) $CH _3CH _2Br$
The correct answer is

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. $I,II$

  2. $III,IV$

  3. $II,III$

  4. $I,II,III,IV$

Show answer
Correct Option: D

Bayer's reagent is

polyhalogen compounds haloalkanes and haloarenes chemistry

  1. $Br _{2}/CCl _{4}$

  2. Cold, dilute alkaline $KMnO _{4}$

  3. Acidified $KMnO _{4}$

  4. $O _{3}/Zn/H _{2}O$

Show answer
Correct Option: B