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 mix and separate dry methods of separation process of separating components of a mixture method of separation

Some iron fillings are mixed with sand. We can separate them using magnetic separation method. This method is applicable only when:

  1. magnetic substances are mixed up with non-magnetic substances

  2. magnetic substances are mixed up with magnetic substances

  3. magnetic substances are heated beyond their Curie temperatures

  4. two magnetic substances have equal melting points
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a mixture of two materials if one have magnetic properties then that material is easily separate by magnet because that material attracted by magnet and other material is not attracted by magnet. 

If both material have magnetic property or both haven't magnetic property then above method doesn't works.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

Which of the following methods is most suitable for obtaining a pure, dry sample of sodium chloride from a mixture of solid sodium chloride and sand?

  1. Shake the mixture with water, filter and dry the residue on the filter paper.

  2. Shake the mixture with water, filter and evaporate the filtrate.

  3. Heat the mixture gently and collect the substance which sublimes

  4. Heat the mixture gently and collect the substance which boils off
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

To obtain dry sample of NaCl from sand, first we have to dissolve it in water;

then, NaCl gets dissolved into water and by filtration we can separate sand particles and after evaporation of water we get dry sample of NaCl.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

In which of the following mixtures hand picking method can be best used?

  1. The mixture of gas and liquid.

  2. The mixture of liquid and liquid.

  3. The mixture of solid and liquid.

  4. The mixture of solid and solid.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hand picking is a method of separation used where one of the component is in small quantity. And it is best for mixture of solids, for eg- Stone in rice.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

How can husk particles be separated from pulses?

  1. By hand picking

  2. By winnowing

  3. By churning

  4. By hydraulic washing
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Winnowing- Winnowing is a method of separation of chaff or husk from wheat/grains. Also called process of separation of heavier components from lighter components by the application of wind.

Hold the container of pulses in the direction of the wind and then shake, pulses being heavier will fall straight down and husks being lighter will fall away due to the wind.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

Sieving is the method used to saperate the particles of

  1. same size

  2. different size

  3. same color

  4. different colour
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the size of particle it too small to be picked by hand,sieving is used for separating substances. A sieve; having pores of certain  size is used. The bigger particles are retained by the sieve whereas the smaller particle are passed  through it. For example; this method is used for separating bran from flour, sand from gravel, pearls of different sizes,etc.

Multiple choice chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

Winnowing is the process used to separate particles of ____________.

  1. heavier and lighter weight

  2. only two heavier particles

  3. only two lighter paticles

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

The process of separation of lighter particles from heavier particles; with the help of wind; is called winnowing. This method is used for separating grains from husk.
Hence option A is correct.

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

All of the following are good laboratory practices except_________.

  1. Wait for a hot object to cool before weighing it.

  2. Rinse a burette with the solution that will be used to fill the times

  3. Wear goggles at all times

  4. Return unused chemicals to the reagent bottles
  5. To dilute $H _2SO _4$, pour it into water slowly.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

We use different equipment to cool the object, before weighting it which save time.

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

Two students are working on an AP Chemistry lab. Their assignment is to determine experimentally the density of a nonvolatile organic liquid, limestone. The accepted value for the density of limestone is $0.8422\ g/mL$. Each student conducts three separate density determinations, then calculates a mean (average) value for the density and the standard deviation for their three trials.

Student A Student B
Density #$1$ $0.8421 g/mL$ $0.8408 g/mL$
Density #$2$ $0.8514 g/mL$ $0.8502 g/mL$
Density #$3$ $0.8355 g/mL$ $0.8332 g/mL$
Mean Density $0.8430 g/mL$ $0.8414 g/mL$
Standard Deviation $0.0080$ $0.0085$

The results and calculations for each students are shown in the table below.
Of the four descriptions given below, which BEST interprets the accuracy and precision of Student A and Student B?

  1. Student A and Student B are equally precise, but Student B has more accurate results.

  2. Student A and Student B are equally accurate, but Student B has more precise results.

  3. Student A and Student B have equal accuracy and equal precision.

  4. Student A has more accurate and more precise results than Student B.
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice chemistry separation of matter filtration and crystallisation other methods of separation separation techniques

Crystallisation is better than simple evaporation because :

  1. some impurities may remain in the solution after filtration

  2. some solids decompose or heating

  3. both A and B

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

Some solids decompose or some, like sugar, may get charred on heating to dryness. Some impurities may remain dissolved in the solution even after filtration. On evaporation these contaminate the solid. So, crystallisation is better than evaporation.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Mixute of ammonium chloride and sodium chloride can be seperated by :

  1. distillation

  2. chromatography

  3. sublimation

  4. all of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Substances like camphor, ammonium chloride, naphthalene, benzoic acid, iodine sublime on heating.
$\underset{(Impure)}{Solid}    \xrightarrow{\Delta}     vapour     \xrightarrow{cool}    \underset{Sublimate}{solid(pure)}$

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

A mixture of barium sulphate and $H _2O$ can be separated by the method of filtration.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A mixture of barium sulphate and $H _2O$ can be separated by the method of filtration. Barium sulphate is insoluble in water.  During filtration, barium sulphate remains on the filter paper and water passes as through filter paper as filtrate.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Sublimation is used to separate :

  1. two liquids having different boiling points

  2. two liquids having same melting point

  3. volatile and non volatile solids

  4. volatile solids having same melting point
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Which of the following mixtures cannot be separated by sublimation?

  1. Salt and ammonium chloride

  2. Salt and naphthalene

  3. Salt and camphor

  4. Camphor and naphthalene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Ammonium chloride, camphor, anthracene, napthalene can sublime but common salt cannot sublime. Hence, option D is correct.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Which technique is used to separate salt from the filtrate after sublimation of ammonium chloride? 

  1. Evaportion

  2. Condensation

  3. Centrifugation

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

Evaporation technique is used to separate salt from the filtrate. Common salt does not decompose during evaporation. As the water evaporates, fewer and fewer water molecules are present to keep the salt particles apart. The salt therefore recrystallizes and can be collected.