Separation Techniques Flashcards
What is a separation technique?
A separation technique is a method used to separate mixtures based on their physical or chemical properties.
What properties can be used to apply separation techniques?
State of matter, solubility in water, rate of migration over an adsorbent, ability to be attracted by a magnet, boiling point, size of the particle, density, and reactivity.
What is sieving?
Sieving is a separation method used to separate particles of different sizes using a sieve.
Give an example of a mixture that can be separated by sieving.
A mixture of stones and sand.
What is filtration?
Filtration is a method used to separate a solid-liquid mixture using a filter paper, where the liquid that passes through is called the filtrate, and the solid that remains is called the residue.
In filtration, should the solid be soluble or insoluble in the liquid?
The solid must be insoluble, otherwise, it would dissolve in the liquid, rendering filtration ineffective.
What is decantation?
Decantation is a technique used to separate immiscible liquid-liquid mixtures or suspensions of solids in liquids by allowing the layers to form and then pouring off one layer.
How is decantation different from sedimentation?
Sedimentation allows heavier particles to settle, while decantation involves removing the liquid layer without disturbing the sediment.
What is centrifugation?
Centrifugation is a technique used to separate suspensions of solids in liquids by applying centrifugal force in a centrifuge.
Where is centrifugation commonly used?
In medicine to separate blood components and in washing machines to separate dirt from clothes.
What is magnetic separation?
Magnetic separation is a technique used to separate magnetic substances from non-magnetic ones.
Give an example of a mixture that can be separated by magnetic separation.
A mixture of iron filings and sulfur powder.
What is sublimation?
Sublimation is a technique used to separate volatile solids (sublimes) from non-volatile solids, where the solid vaporizes directly without passing through a liquid phase.
List examples of substances that sublime.
Iodine, camphor, ammonium chloride, dry ice, and naphthalene.
What is the method used to separate a mixture of ammonium chloride and iodine?
Sublimation, because ammonium chloride sublimes at a lower temperature compared to iodine.
What is evaporation?
Evaporation is a technique used to separate soluble solid particles from liquids by heating the mixture until the liquid evaporates, leaving the solid behind as residue.
What are the drawbacks of evaporation?
Evaporation doesn’t remove impurities, and some substances may decompose upon heating.
What is crystallization?
Crystallization is a technique used to recover dissolved solutes from a supersaturated solution in the form of crystals.
What is the principle behind crystallization?
Crystallization is based on the principle that solubility increases with temperature, and cooling a supersaturated solution allows crystals to form.
What is distillation?
Distillation is a separation technique used for liquid-liquid mixtures based on differences in boiling points or volatilities.
What is the difference between simple and fractional distillation?
Simple distillation is used for mixtures with a wide difference in boiling points, while fractional distillation is used for mixtures with a small difference in boiling points.
What is an azeotropic mixture?
An azeotropic mixture is a constant boiling mixture that cannot be completely separated by distillation or fractional distillation.
What method is used to separate the color extracts of a flower?
Chromatography.
What method is used to separate a powdered mixture of alum and chalk?
Filtration, followed by evaporation to dry the alum.
