⚡ Show all working — the AI marks against the AQA mark scheme. Method marks awarded for correct working even if the final answer is wrong.
1 markGas testAQA 8462 style
What is the test for carbon dioxide, and what is observed if CO2 is present?
A Hold burning splint at mouth of tube — squeaky pop
B Hold glowing splint at tube — splint relights
C Bubble gas through limewater — turns milky/cloudy
D Damp blue litmus paper held at tube — turns red then white
4 marksFlame test identificationAQA 8462 style
A student carries out flame tests on four unknown metal salt solutions. Solution A gives a yellow flame, solution B gives a crimson flame, solution C gives a lilac flame, and solution D gives a green flame. Identify the metal ion in each solution. (4 marks)
Hint: Learn the flame test colours: sodium=yellow, lithium=crimson, potassium=lilac, copper=green, calcium=orange-red.
+40 XP
3 marksDistinguish iron ionsAQA 8462 style
A solution contains either iron(II) ions or iron(III) ions. Describe how you would use sodium hydroxide solution to identify which ion is present. Include the expected observations for each. (3 marks)
Hint: Add NaOH to the solution. Observe precipitate colour. Fe2+ = pale green. Fe3+ = orange-brown. Name the precipitate formed.
+30 XP
1 markHalide identificationAQA 8462 style
Dilute nitric acid and then silver nitrate solution are added to an unknown solution. A cream precipitate forms. Which halide ion is present?