The cards Question In chemistry, what is a mixture? Tap to flip Answer A material made of two or more different substances that can be separated by physical means. Question What happens to the chemical properties of each substance in a mixture? Tap to flip Answer They stay unchanged. Question What is a formulation? Tap to flip Answer A designed mixture in which each component serves a specific purpose in the product. Question What is a solute? Tap to flip Answer A substance that has dissolved into a solvent. Question What is a solvent? Tap to flip Answer A liquid into which a solute dissolves. Question Which is the most common solvent? Tap to flip Answer Water. Question Is dissolving a solute to make a solution a physical or a chemical change? Tap to flip Answer A physical change: evaporating the water from salt solution leaves salt crystals, so salt and water have not chemically combined. Question What does filtration separate? Tap to flip Answer Insoluble solids from a liquid, by passing the mixture through a filter. Question In filtration, what is the filtrate? Tap to flip Answer The liquid component separated from the mixture. Question In filtration, what is the residue? Tap to flip Answer The insoluble component collected in the filter paper. Question What difference between particles allows filtration to separate them? Tap to flip Answer A difference in the size of the particles. Question What is a saturated solution? Tap to flip Answer A solution in which no more solute can dissolve in the solvent at a given temperature. Question Which separation technique forms solid crystals from a saturated solution by continued removal of the solvent? Tap to flip Answer Crystallisation. Question How does evaporation differ from boiling? Tap to flip Answer Evaporation happens only at the surface of the liquid, with no bubbles forming; in boiling, gas bubbles form. Question What are the two phases in chromatography? Tap to flip Answer The stationary phase and the mobile phase. Question In chromatography, what is the stationary phase? Tap to flip Answer The surface along which the solvent and dissolved components travel; it does not move. Question What is a chromatogram? Tap to flip Answer The pattern of a sample's components left on the stationary phase after chromatography. Question In chromatography, what is the solvent front? Tap to flip Answer The furthest distance the solvent travels along the stationary phase. Question What does an Rf value compare? Tap to flip Answer The distance a component of the sample travelled with the distance the solvent travelled under the same conditions. Question What does 'Rf' stand for? Tap to flip Answer Retention factor. Question For a fair comparison of chromatograms, which factors must be considered? Tap to flip Answer The choice of stationary and mobile phases, the sample concentration and the temperature. Question Which two processes does distillation use to isolate a liquid from a mixture? Tap to flip Answer Boiling and condensation. Question Distillation separates a soluble substance from its solvent based on differences in which property? Tap to flip Answer Boiling point. Question What is a condenser made of? Tap to flip Answer A tube surrounded by a cold layer, usually cold water. Question In distillation, what is the distillate? Tap to flip Answer The condensed component that has been isolated. Question Simple distillation is used mainly to separate mixtures of how many components? Tap to flip Answer Only two components. Question Why does heating a mixture strongly during distillation give a poorer result? Tap to flip Answer Several components may enter the condenser or delivery tube, contaminating the distillate. Question Which piece of apparatus mainly distinguishes fractional distillation from simple distillation? Tap to flip Answer A fractionating column. Question What develops inside a fractionating column? Tap to flip Answer A temperature gradient. Question Is every fraction from fractional distillation a pure substance? Tap to flip Answer No. A fraction can be pure or a mixture of chemicals with very similar boiling points. Question What is potable water? Tap to flip Answer Water that is safe to drink. Question What does pure water contain? Tap to flip Answer Only H₂O molecules. Question Which two processes are used to obtain potable water from groundwater and fresh water? Tap to flip Answer Filtration and sterilisation. Question What is sterilisation? Tap to flip Answer The process of killing bacteria and other living microorganisms. Question By which two methods can desalination of seawater produce potable water? Tap to flip Answer Distillation or reverse osmosis. Question In wastewater treatment, what is sludge? Tap to flip Answer The solid collected after sedimentation. Question How does sewage differ from wastewater? Tap to flip Answer Wastewater is any used water from domestic, industrial and agricultural processes; sewage is the part contaminated with faeces and urine. Question When sludge is treated anaerobically, what can the products be used as? Tap to flip Answer Fertiliser or fuel. Question What pH must pure water used for laboratory tests have? Tap to flip Answer pH 7 (neutral). Question Why are not all water samples neutral? Tap to flip Answer Their acidity or alkalinity is affected by the substances dissolved in them. Question What set-up can be used to collect the dissolved solids from a water sample? Tap to flip Answer An evaporation set-up. Question At what temperature does pure water boil? Tap to flip Answer 100 °C. Question How do impurities affect the way a water sample boils? Tap to flip Answer Its boiling point increases, and the more impurities, the larger the temperature range over which it boils. Where this deck sits in the curriculum Curriculum National Curriculum for England Stage GCSE (Years 10–11) Course GCSE Chemistry Unit Separating substances Exam boards AQA, Edexcel, OCR Tiers foundation and higher England's National Curriculum sets what is taught; the units and their order are Oak National Academy's. Flash Feed is not affiliated with Oak or any exam board.
How this deck was checked On 2026-11-02, every card was compared with its source: the lessons of Oak National Academy, a public body funded by England's Department for Education that publishes lessons for the national curriculum. Because the cards come from those lessons, no second source was sought. The comparison was done automatically, not by a teacher, so a card can still be wrong. Flash Feed is not affiliated with any source named here.
Sources Total: 15 · primary: 15 · second publisher: 0
Show the other sources (13) Primary source Potable water (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Wastewater treatment (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Water sample analysis: pH (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Water sample analysis: dissolved solids (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Water sample analysis: distillation (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Solutions (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Filtration (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Crystallisation (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Chromatography: paper (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Interpreting chromatograms (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Chromatography: separating a mixture of inks (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Distillation: simple distillation (opens in a new tab) (Oak National Academy, thenational.academy) Primary source Distillation: separating a mixture of inks (opens in a new tab) (Oak National Academy, thenational.academy) Found a mistake? Write to support@flashfeed.app .
A Chemistry lesson by Oak National Academy licensed under Open Government Licence (OGL)
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