Chemistry · Science General

Separation Techniques

813 Questions

Separation techniques involve physical methods to isolate mixtures, including distillation, filtration, and crystallization. Competitive exams frequently test these foundational concepts. Review the exact processes to enhance problem solving speed.

Distillation and evaporationCrystallization processFiltration methodsSeparating dissolved solidsChromatography and mass techniques

Separation Techniques Questions

Multiple choice chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

Which of the following represents correct statement(s)?

  1. The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt, stone and husk from wheat, rice or pulses.

  2. The quantity of such impurities is usually very large.

  3. In such situations, we find that handpicking is not a convenient method of separating substances.

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The statement (A) represents correct statement.
The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt, stone and husk from wheat, rice or pulses.
The quantity of such impurities is usually not very large.
In such situations, we find that handpicking is a convenient method of separating substances.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Mercury has low boiling point. Therefore it can be purified by the process of:

  1. liquation

  2. polling

  3. oxidation

  4. distillation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mercury has a low boiling point. Therefore it can be purified by the process of distillation because then mercury will evaporate and collected in pure form and impurities will remain back. 

Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Which of the following mixture can be separated by magnetic separation?

  1. Iron filings, sand and iodine

  2. Common salt, sand and marbles

  3. Chalk powder, grain and chaff

  4. Stone, salt and water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
For option A, the iron filling can be removed by using a magnet. an iron filling will be attracted by a magnet while water and iodine will not.

For option B, marbles can be separated by hand. Now add water salt will dissolve while sand will not. then separate the saltwater and sand.

For option C, winnowing can be used to separate chaff and grains.for chalk powder we can use filtration.

For option D, stone can be removed by handpicking, now water and salt can be separated by boiling the water. so water will evaporate leaving salt behind.
Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Why do we need to separate different components of a mixture? Select the correct explanation from the following.

  1. To remove the unwanted impurities

  2. To obtained pure substances

  3. To separate, two different but useful components

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mixtures have different physical and chemical properties compared with same metals. we need to separate different substances from mixtures as we want only useful substances and to obtain pure substances.

Multiple choice chemistry principles of metallurgy concentration of ore concentration of ores general principles of metallurgy

Which of the following process is not a physical process of separation?

  1. Levigation

  2. Magnetic separation

  3. Leaching

  4. Froth fioatation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leaching involves the treatment of the ore with a suitable reagent to make it soluble while impurity remains insoluble. The ore is recovered from the solution by suitable chemical method.

For example Bayer's process:
Bauxite ore contains impurities like $Fe _2O _3$, $TiO _2$  and $SiO _2$. So, when it dissolve in aq. NaOH/pressure + 150°C T, bauxite dissolves but others donot dissolve. 
$Al _2O _3 + 2NaOH \rightarrow 2NaAlO _2 + H _2O$
$ NaAlO _2 + 2H _2O \rightarrow Al(OH) _3 + NaOH$

Multiple choice chemistry rocks and minerals coal petroleum non-renewable sources of energy

Arrange the following in a proper sequence for the extraction of petroleum.
(a) Processing of crude oil to remove heavy oil.
(b) Heating of the crude oil containing pure mixture of hydrocarbons over a specific range of temperature.
(c) Separation of constituents by fractional distillation.
(d) Purification of crude oil containing salt water.
(e) Drilling of the oil through the various layers under the earth's surface.

  1. ebadc

  2. ecabd

  3. eadbc

  4. eabcd
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct sequence is :
(i) Drilling of the oil through the various layers under the earth's surface.
(ii) Processing of crude oil to remove heavy oil.
(iii) Purification of crude oil containing salt water.
(iv) Heating of the crude oil containing pure mixture of hydrocarbons over a specific range of temperature.
(v) Separation of constituents by fractional distillation.

Multiple choice chemistry world energy needs coal petroleum non-renewable sources of energy

In the refining of petroleum, in a fractionating column, the principle used is _______.

  1. difference in melting point

  2. difference in boiling point

  3. difference in freezing point

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A fractionating column is an essential thing which is used in distillation of liquid mixtures so as to separate the mixture into its component parts, or fractions, based on the differences in their boiling temparatures. Fractionating columns are used in small scale laboratory distillation process as well as for large scale industrial distillations.

Hence option B is correct.

Multiple choice chemistry world energy needs coal petroleum non-renewable sources of energy

Which step is not present in the extraction of petroleum?

  1. Pumping

  2. Drilling

  3. Distillation

  4. Seismic survey
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Procedure for extraction of petroleum:

i) Locating the oil field or seismic survey
ii) Drilling
iii) Oil extraction and recovery ( involves pumping)
Distillation is used for extracting different petroleum products like petrol, diesel, natural gas from petroleum.
Hence, the correct option is $C$.

Multiple choice chemistry world energy needs coal petroleum non-renewable sources of energy

________ is a process by which components in a chemical mixture are separated into different parts according to different boiling points in a fractionating column.

  1. Vacuum distillation

  2. Steam distillation

  3. Fractional distillation

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vacuum distillation is a distillation of a liquid under reduced pressure, enabling it to boil at a lower temperature than normal.

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.

Fractional distillation is a separation of a liquid mixture into fractions differing in boiling point (and hence chemical composition) by means of distillation, typically using a fractionating column.

Multiple choice chemistry world energy needs coal petroleum non-renewable sources of energy

Petroleum refining involves:

  1. vacuum distillation

  2. steam distillation

  3. fractional distillation

  4. fractional crystallisation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The various fractions of petroleum are separated by fractional distillation.
Fractional distillation is one separation of a mixture into its components parts, or fractions, sour as in separating chemical compounds by their boiling point by heating them to a temp at which one or more fractions of the compound will vaporize.