Tag: methods of purification of organic compounds

Questions Related to methods of purification of organic compounds

Styrene can be purified by:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. Simple distillation

  2. Fractional distillation

  3. Vacuum distillation

  4. Steam distillation

Show answer
Correct Option: C

The standard reduction potentials of $Pt|Cr {2}O _{7}^{2-}, Cr^{+3}; Pt|MnO _{4}^{-}, Mn^{+2}; Pt|Ce^{+4}, Ce^{+3}$ in the presence of acid are 1.33 V, 1.51 V and 1.61 V, respectively, at $25^{\circ}C$. The decreasing order of oxidizing power is _________________.

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. $Cr _{2}O _{7}^{2-} > MnO _{4}^{-} > Ce^{+4}$

  2. $MnO _{4}^{-}> Cr _{2}O _{7}^{2-} > Ce^{+4}$

  3. $Ce^{+4} > MnO _{4}^{-}> Cr _{2}O _{7}^{2-}$

  4. $MnO _{4}^{-} > Ce^{+4} > Cr _{2}O _{7}^{2-}$

Show answer
Correct Option: C

Which of the following compounds can be purified by vacuum distillaiton?

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. Glycerine

  2. Glycerol

  3. Propane-$1, 2, 3$-triol

  4. Ethanol

Show answer
Correct Option: A,B,C
Explanation:

Vacuum distillation is used when the boiling point of the compound or the solvent is too high in order to distill the compound or the solvent off without significant decomposition. It is based on the fact that under vacuum the boiling point of the materials is lower than at normal atmospheric pressure. Glycerine, glycerol and propone 1,2,3-triol are the three names of the same compound. It has a boiling point of 290$^oC$ while ethanol has BP 79$^oC$ .

Option A, B and C are correct.

p-nitrophenol and o-nitrophenol are separated by?

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. Crystallisation

  2. Fractional distillation

  3. Distillation

  4. Steam distillation

Show answer
Correct Option: D

$ H _{2}O _{2}$ can be prepared by successive reactions:
$ 2NH _{4}HSO _{4}\rightarrow H _{2}+(NH _{4})^{2}S _{2}O _{8}$
$ (NH _{4}) _{2}S _{2}O _{8}+2H _{2}O \rightarrow  2NH _{4}HSO _{4}+ H _{2}O _{2}$
The first reaction is an electrolytic reaction and second is steam distillation. What amount of current would have to be used in first reaction to produce enough intermediate to yield 102 g pure $ H _{2}O _{2}$ per hour. Assume current efficiency 50 %.

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. 643.33 A

  2. 321.67 A

  3. 160.83 A

  4. 1286.67 a

Show answer
Correct Option: B

Which of the following compounds can be purified by steam distillation?

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. Salicylaldehyde

  2. Bromobenzene

  3. p-Hydroxy benzaldehyde

  4. Nitrobenzene

Show answer
Correct Option: A,B,D

Osazone formation is used to separate and identify.

bio-chemistry biochemical techniques methods of purification of organic compounds methods of purification - organic compounds chromatography

  1. Alcohols

  2. Carboxylic acids

  3. Carbohydrates

  4. Starch

Show answer
Correct Option: C

Turpentine oil can be purified by:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. steam distillation

  2. vaccum distillation

  3. fractional distillation

  4. sublimation

Show answer
Correct Option: A
Explanation:

Steam distillation of a liquid in a current of steam used especially to purify liquids that are not very volatile and are immiscible with water. The boiling point of turpentine oil is between 90 and 115 °C or 195 and 240 °F and is immiscible with water. Thus, it is purified by steam distillation.

Absolute alcohol can be prepared from rectified spirit by:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. Azeotropic distillation with benzene

  2. Fractional distillation

  3. Keeping over fresh CaO for few hours and then distilling

  4. Distillation under reduced pressure

Show answer
Correct Option: A,C

A mixture of camphor and benzoic acid can be easily separated by?

bio-chemistry biochemical techniques methods of purification of organic compounds methods of purification - organic compounds chromatography

  1. Sublimation

  2. Fractional distillation

  3. Chemical method

  4. Extraction with solvents

Show answer
Correct Option: C
Explanation:

Aqueous solution of $NaHCO _3$ can be used to separate benzoic acid from its mixture with camphor. Benzoic acid forms water soluble sodium benzoate with $NaHCO _3$. So, A mixture of camphor and benzoic acid can be easily separated by Chemical method.

Option C is correct.