Tests for carbonate, sulfate, sulfite, nitrate and the halide ions, the laboratory tests for the common gases including water, and how to plan an unknown-identification investigation.
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.
Every food-safety inspector, forensic lab and water-testing team uses the same logic as this lesson: add a reagent and read the evidence.
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.
Dilute acid → CO₂, limewater milky.
Dilute acid → SO₂; KMnO₄ decolourised.
BaCl₂ after acid: white ppt insoluble in acid.
Heat: brown NO₂; Al + NaOH: NH₃.
AgNO₃: white, cream, yellow; NH₃ solubility differs.
Squeaky pop; relights glowing splint.
Damp red litmus blue; KMnO₄ decolourised; bleaches; brown gas.
CuSO₄ white → blue; CoCl₂ paper blue → pink.
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 white solid, T, was analysed. It effervesced with dilute hydrochloric acid, releasing a colourless gas.
(a) (a) State a chemical test for the gas, and the result if it is carbon dioxide. [2]
(b) (b) Write an ionic equation for the reaction of carbonate with acid. [2]
(c) (c) Describe a test for the sulfate ion and state the expected observation. [3]
(d) (d) Describe how chloride, bromide and iodide ions can be distinguished using silver nitrate and ammonia. [3]
(e) (e) State the test and the result for each of ammonia gas and chlorine gas. [4]
(f) (f) State how water can be shown to be produced in a reaction. [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.