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Purity, formulations and chromatography key terms
Use these key terms for Purity, formulations and chromatography in AQA Chemistry 8462. The page is built from approved learning objectives for this topic and links back to the wider unit, topic hub, and related revision assets.
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key terms
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Topic
Purity, formulations and chromatography
Key terms
Pure substance
A single element or compound not mixed with any other substance.
Impurity
A substance that alters the properties of a pure substance, affecting its melting and boiling points.
Pure Substance
A single element or compound not mixed with any other substance.
Melting Point
The specific temperature at which a pure element or compound changes from solid to liquid.
pure substance
A single element or compound not mixed with any other substance.
melting point
The specific temperature at which a pure substance changes from solid to liquid.
Pure substance
A single element or compound not mixed with any other substance.
Boiling point
The temperature at which a substance changes from liquid to gas, used to identify pure substances.
Melting point depression
The lowering of a substance’s melting point caused by the presence of impurities.
Boiling point elevation
The increase in a substance’s boiling point caused by the presence of impurities.
Melting Point
The temperature at which a solid becomes a liquid, used to identify pure substances.
Boiling Point
The temperature at which a liquid becomes a gas, used to identify pure substances.
Pure substance
A single element or compound not mixed with any other substance.
Everyday purity
The general concept of purity that may include mixtures or impurities, differing from the scientific definition.
formulation
A mixture that has been designed as a useful product.
mixture
A combination of two or more substances that are not chemically bonded.
formulation
A mixture that has been designed as a useful product.
component
An individual substance that is mixed in a formulation in carefully measured quantities.
formulation
A mixture that has been designed as a useful product.
component
An individual part or ingredient that makes up a formulation.
formulation
A mixture that has been designed as a useful product.
cleaning agent
A formulation specifically designed to remove dirt and stains.
formulation
A mixture that has been designed as a useful product.
component
An individual part of a formulation that contributes to the properties of the product.
formulation
A mixture that has been designed as a useful product.
composition
The specific components and their amounts that make up a formulation.
formulation
A mixture that has been designed as a useful product.
pure substance
A single element or compound not mixed with any other substance.
Chromatography
A method used to separate mixtures and identify substances based on their movement through a stationary phase and a mobile phase.
Mixture
A combination of two or more substances that are not chemically bonded together.
stationary phase
The phase in chromatography that remains fixed in place and does not move.
mobile phase
The phase in chromatography that moves and carries the substances to be separated.
Mobile phase
The phase that moves through the stationary phase, carrying substances with it during chromatography.
Stationary phase
The phase that remains fixed in place, against which substances are separated based on their distribution between the two phases.
Chromatography
A method used to separate mixtures and identify substances based on their movement through a stationary phase and a mobile phase.
Soluble substances
Substances that can dissolve in a solvent, allowing for separation and identification through techniques such as paper chromatography.
chromatogram
A visual representation of the separation of components in a mixture using chromatography.
mixture
A combination of two or more substances that are not chemically bonded together.
Chromatogram
A visual representation of the results of chromatography, showing the separation of substances.
Pure substance
A material that consists of only one type of particle, resulting in a single spot on a chromatogram.
chromatogram
A visual representation of the separation of substances in a mixture using chromatography.
mixture
A combination of two or more substances that are not chemically bonded together.
chromatogram
A visual representation of the separation of substances in a mixture, showing the positions of the spots.
unknown substance
A substance whose identity is not known and is being compared against known substances in chromatography.
Rf value
The ratio of the distance moved by a substance to the distance moved by the solvent front in chromatography.
chromatogram
A visual representation of the results of chromatography, showing the separated substances as spots.
Rf value
The ratio of the distance moved by a substance to the distance moved by the solvent front in chromatography.
chromatogram
A visual record of the separation of substances in a mixture, showing the positions of the spots corresponding to different components.
Rf value
The ratio of the distance moved by a substance to the distance moved by the solvent front in chromatography.
chromatogram
A visual representation of the results of chromatography, showing the separation of substances.
chromatography
A method used to separate mixtures and identify substances.
Rf value
The ratio of the distance moved by a substance to the distance moved by the solvent in chromatography.
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