14.1 and 14.2 (Apparatus used for measurement and Separating mixtures) Chemistry

Burette

Apparatus used to deliver variable volumes of a liquid accurately, especially in titrations

Pipette

Apparatus used to measure and transfer a fixed volume of solution accurately

Conical flask

Used to contain solutions during titrations; prevents splashing while swirling

Measuring cylinder

Used to measure approximate volumes of liquids

Volumetric flask

Used to prepare accurate fixed volumes of solutions

Gas syringe

Used to measure the volume of gases produced in an experiment

Balance

Used to measure the mass of substances accurately

Thermometer

Used to measure the temperature of substances

Stopwatch

Used to measure the time taken for reactions or processes

Filter funnel

Used with filter paper to separate solids from liquids

Evaporating basin

Used to evaporate solvent from a solution to obtain a solid residue

Beaker

Used for holding and mixing liquids; not very accurate for measuring volumes

Mixture

A combination of two or more substances that are not chemically bonded

Filtration

Separation method used to remove insoluble solids from a liquid

Residue

The solid left behind on the filter paper after filtration

Filtrate

The liquid that passes through the filter paper in filtration

Crystallisation

Technique used to obtain a pure solid from a solution by evaporating the solvent and allowing crystals to form

Evaporation to dryness

Heating a solution until all solvent is removed, leaving the solute behind (may decompose some solids)

Simple distillation

Separation of a solvent from a solution by evaporation and condensation

Fractional distillation

Separation of a mixture of liquids with different boiling points using a fractionating column

Example of fractional distillation

Separating ethanol from water, or separating crude oil fractions

Separating funnel

Apparatus used to separate immiscible liquids (e.g., oil and water)

Chromatography

Method used to separate and identify substances in a mixture based on their solubility and movement on paper

Rf value

Ratio of the distance travelled by a substance to the distance travelled by the solvent front in chromatography

Paper chromatography

A technique where spots of substances are placed on paper and separated as the solvent moves up the paper

Why different substances move different distances in chromatography

They have different solubilities in the solvent and different attractions to the paper