Tag: separation techniques

Questions Related to separation techniques

A separating funnel is used to separate the components of a mixture of:

  1. iodine and sugar

  2. ethanol and water

  3. cooking oil and water

  4. ammonium chloride and iron filings


Correct Option: C
Explanation:

A separating funnel is used to separate the components of a mixture of cooking oil and water. A separating funnel is used to separate the components of a mixture of two immiscible liquids. Cooking oil and water are two immiscible liquids.

A public health inspector suspects that in addition to two harmless dyes (boiling points $69\ ^oC$ and $71\ ^oC$), a lollipop also contains a poisonous green dye (boiling point $73\ ^oC$). Which of the following can be used to confirm his suspicion?

  1. Fractional distillation

  2. Paper chromatography

  3. Filtration

  4. Crystallization


Correct Option: B
Explanation:

A public health inspector suspects that in addition to two harmless dyes(boiling points 69 C and 71 C), a lollipop also contains a poisonous green dye (boiling point 73 C). Paper chromatography can be used to confirm his suspicion. Here, different dyes will have different affinity for paper (stationary phase) and solvent (mobile phase). Fractional distillation is used when individual components of mixtures have boiling points more than 30 C. Filtration and crystallisation are used in separation / purification of solid from liquid.

John tried to separate sugar from its solution using the evaporation method. However, he was unsuccessful. Which of the following is the likely reason?

  1. There was insufficient sugar in the solution

  2. He had forgotten to stir the solution during heating

  3. The sugar had decomposed

  4. The sugar had vaporised.


Correct Option: C
Explanation:
John tried to separate sugar from its solution using the evaporation method. However, he was unsuccessful as the sugar had decomposed. When you sugar (sucrose) is heated, it undergoes dehydration. The crystalline structure breaks down. Molecules decompose into glucose and fructose and then lose water and polymerize to form caramel, which is a red-orange colored solid.

Sand that is needed for a project has some common salt accidentally mixed with it. which of the following processes need to be used to separate sand and salt?
1. Filtration
2. Evaporation
3. Distillation
4. Crystallisation

  1. 1, 2

  2. 1,2 and 4

  3. 1, 2 and 3

  4. 1,2,3 and 4


Correct Option: A
Explanation:

To separate the mixture of salt and sand;

first we will make the aqueous solution, salt gets dissolved in water and sand particle remain undissolved,
so, the misture can be separated by filtration and evaporation.