Identifying alcohols, acids and esters by functional groups, how properties depend on the –OH and –COOH groups, the reactions of ethanol, fermentation, and the reactions of ethanoic acid.
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.
Rum, vinegar and the smell of ripe fruit all come from the same chemistry. A change in one functional group turns an alcohol into an acid and then into an ester.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Find the –OH and –COOH functional groups.
Copy these into your notebook in your own words — that is how they stick.
R–OH; neutral; soluble when short; reacts with sodium (H₂).
R–COOH; weak acid; reacts with metals, bases, carbonates and alcohols.
R–COO–R′; sweet smelling; insoluble.
Explains solubility and higher boiling points.
Acidified K₂Cr₂O₇ (orange → green) → ethanoic acid.
Conc. H₂SO₄ or Al₂O₃ → ethene + water.
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂; yeast; 25–35 °C; anaerobic.
Acid + alcohol ⇌ ester + water (conc. H₂SO₄).
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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]
Ethanol can be made by fermentation of glucose and by hydration of ethene.
(a) (a) Write a balanced equation for the fermentation of glucose. [2]
(b) (b) State two conditions needed for fermentation. [2]
(c) (c) Describe how ethanol can be separated from the fermented mixture. [2]
(d) (d) Describe what happens when sodium is added to ethanol and write an equation. [3]
(e) (e) Name the product formed and the colour change when ethanol is warmed with acidified potassium dichromate(VI). [2]
(f) (f) Write the equation for the reaction between ethanol and ethanoic acid and name the catalyst. [3]
(g) (g) Explain why ethanoic acid is classified as a weak acid. [1]
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.