Chemistry · Science General

Separation Techniques

842 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

By which method can you separate a mixture of NaCl and water?

  1. Sublimation

  2. Distillation

  3. Solvent extraction

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

Distillation is the correct method because NaCl (salt) has a much higher boiling point than water, so when the solution is heated, water evaporates first and can be collected as distillate, leaving solid salt behind. Sublimation is for solids that directly vaporize, solvent extraction requires another solvent, and liquefaction is converting gas to liquid - none of these separate salt from water effectively.

Multiple choice

Filtration is used to separate _______ from a liquid.

  1. gases

  2. liquid

  3. solid

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

Filtration specifically separates undissolved solid particles from a liquid - the filter paper allows the liquid to pass through while trapping solid particles. Gases pass through filters, liquids mix with liquids, and 'all of these' would be incorrect because filtration cannot separate gases or miscible liquids.

Multiple choice

The process of evaporation is used to separate

  1. cream from milk

  2. sugar from water

  3. alcohol from water

  4. sand from water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation separates sugar from water because when you heat a sugar solution, water (with lower boiling point) evaporates into the air, leaving solid sugar crystals behind. This works because sugar is non-volatile and has a much higher boiling point than water. Cream separation uses centrifugation or churning, alcohol-water separation requires distillation due to closer boiling points, and sand-water would use filtration or sedimentation.

Multiple choice

Which method is used to separate sugar and sand?

  1. Magnetic separation

  2. Gravity separation

  3. Mechanical picking

  4. Solvent extraction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

They can be separated by gravity separation as sugar is soluble in water and sand is heavier.

Multiple choice

Which of the following is not common to evaporation and distillation?

  1. Heating of liquid

  2. Separation of solid-liquid mixtures

  3. Separation and recovery of dissolved solid and liquid

  4. Conversion of liquid to vapour
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Separation and recovery of dissolved solid and liquid is possible only in distillation. It is not possible in evaporation.