GCE O-Level Chemistry: Experimental Techniques and Separation Methods

Vocabulary flashcards covering experimental chemistry apparatus, gas collection methods, and physical separation techniques from Singapore GCE O-Level Chemistry exam revision notes.

Singapore GCE O-Level

The Singapore-Cambridge General Certificate of Education Ordinary Level examinations.

Immiscible Liquids

Liquids that do not mix or dissolve in one another and form separate layers; when placed in a container, the liquid with the higher density forms the bottom layer.

Separating Funnel

A laboratory apparatus used to separate immiscible liquids, allowing the lower, denser liquid to be drained out first through a stopcock.

Fractional Distillation

A separation method used to separate liquids with different boiling points, in which the liquid with the lower boiling point boils off and is collected first.

Styrofoam Cup

A piece of apparatus used as an insulator to contain reaction mixtures and minimize heat loss when measuring temperature changes during a reaction.

Gas Syringe

A piece of apparatus used to collect and accurately measure the volume of a gas evolved during a chemical reaction, such as hydrogen gas produced from magnesium and dilute hydrochloric acid.

Upward Delivery

A gas collection technique used specifically for collecting gases that are less dense than air.

Displacement of Water

A gas collection technique suitable for collecting gases that are insoluble in water.

Paper Chromatography

An analytical separation technique used to separate and identify components of a mixture, such as the different dyes present in a sample of ink.

Start Line

The baseline on chromatography paper where sample spots are applied, which must be placed above the level of the solvent to prevent the samples from dissolving directly into the solvent.

Solvent Front

The highest level reached by the moving solvent as it travels up the chromatography paper.

$R_f$ Value

The retention factor in chromatography; a substance that travels a shorter distance relative to the solvent front has a lower $R_f$ value.

Locating Agent

A substance applied to a dry chromatogram to detect and visualize colorless spots.

Sublimation (Separation Technique)

A separation method used to separate a substance that turns directly from a solid to a vapor upon heating, such as obtaining iodine from a mixture of iodine and nickel.

Simple Distillation

A separation process used to obtain a pure liquid solvent from a solution of a dissolved non-volatile solute, such as obtaining pure water from sodium chloride solution.

Evaporation (Separation Technique)

A separation method used to obtain a dissolved solid solute from a solution by heating to remove the liquid solvent, such as recovering solid sodium chloride from aqueous sodium chloride.