How temperature affects the solubility of solids, and how to choose and describe filtration, evaporation, crystallisation, simple and fractional distillation, chromatography and the separating funnel, including sugar extraction.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Sugar cane is crushed in the field and ends up as sparkling crystals in your kitchen. Along the way, the chemist uses almost every separation technique in the book.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
Mass dissolving in 100 g of water at a stated temperature; most solids more soluble when hot.
Insoluble solid from liquid: residue and filtrate.
Recover a dissolved solid; crystallise to get pure crystals.
Solvent from a solution; condense the vapour.
Miscible liquids with different boiling points.
Rf = distance by spot ÷ distance by solvent; use a pencil line.
Immiscible liquids: run off the denser one first.
Crush → lime → filter → vacuum evaporation → crystallise → centrifuge.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Chemistry Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (15 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [15 marks]
A student has a mixture of sand, salt and water and also a mixture of ethanol and water.
(a) (a) Describe how the student can obtain dry sand and solid salt from the first mixture. [5]
(b) (b) Name the technique used to separate ethanol from water and state the property used. [2]
(c) (c) Draw a labelled diagram of the apparatus used for simple distillation. [4]
(d) (d) A chromatogram shows a spot 4.5 cm from the baseline when the solvent front is 9.0 cm. Calculate the Rf value. [2]
(e) (e) Explain why potassium nitrate crystals form when a hot saturated solution cools. [2]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.