Separating the Components of a Mixture

Vocabulary practice flashcards covering various methods and terminology used in the separation of components of a mixture as described in the science lecture notes.

Threshing

The process of separating wheat grains from the stalk by beating the stalks on the ground or by using a mechanical thresher.

Winnowing

The process of separating grains from chaff by the action of wind, utilizing the property that grain is heavier than chaff.

Hand-picking

A method used to separate unwanted substances like stones from rice or cereals when the particles are different in shape, size, or colour and the mixture is small in quantity.

Magnetic Separation

A process that uses a magnet or electromagnet to separate magnetic substances, such as iron filings, from non-magnetic substances.

Sieving

A process to separate particles of different sizes by passing the smaller particles through the pores of a sieve while leaving the bigger particles behind.

Sublimation

The process in which some solid substances, when heated, change directly into vapours without passing through the intermediate liquid state.

Sedimentation

The process of leaving a mixture undisturbed to allow heavy, insoluble solid particles (sediment) to settle at the bottom of the liquid constituent.

Decantation

The process of separating the clear liquid (supernatant) from the sediment by simply pouring it out into another container.

Supernatant

The clear liquid that remains above the sediment after the process of sedimentation is complete.

Filtration

A technique to separate insoluble solid particles from a liquid by passing the mixture through a filter, such as a filter paper.

Crystallisation

The process of obtaining a pure solid in the form of crystals from its saturated solution, typically by cooling a hot saturated solution.

Mother liquor

The solution containing left-behind impurities that remains after crystals have formed during the process of crystallisation.

Evaporation

A method used for separating a soluble solid from its solution by heating it until the volatile solvent evaporates, leaving the non-volatile solute behind.

Simple Distillation

The process of converting a liquid into vapours followed by condensation to obtain a pure liquid, used for mixtures with boiling point differences greater than $25\,^{\circ}\text{C}$.

Immiscible Liquids

Liquids that do not mix with each other and form separate layers based on their densities, such as oil and water.

Separating Funnel

A laboratory apparatus used to separate two immiscible liquids by pouring out the heavier lower layer first.

Fractional Distillation

A process used to separate miscible liquids whose boiling points differ by less than $25\,^{\circ}\text{C}$ using a fractionating column.

Centrifugation

A method based on density differences where a mixture is rapidly rotated to force heavier denser particles to the bottom and lighter particles to the top.

Chromatography

A separation technique used for solutes that dissolve in the same solvent, such as separating colours in a dye or drugs in blood.

Coagulation

A separation technique where very fine suspended particles in a liquid come together to form larger particles called flocs so they can settle easily.

Alum

A substance often used as a coagulant in water treatment to neutralize charges on small particles, causing them to gather and settle.

Screening

The first step in water purification where water is passed through screens with large numbers of holes to retain floating matter.

Aeration

The process in water purification where air is passed through filtered water to kill microorganisms and saturate it with oxygen.

Chlorination

A disinfection step in water purification where a calculated concentrated solution of chlorine is mixed with water to kill harmful disease-causing microorganisms.

Sterilisation of water

The process of killing disease-causing bacteria and microorganisms from water to make it safe for human use.