Acids and Alkalis: "HAcids = H⁺ ions. Alkalis = OH⁻ ions." The letter A connects both to their ions.
Indicator colours (three key ones):
- Litmus: Red in acid, Blue in alkali — remember "Red = Acidic, Blue = Alkaline"
- Phenolphthalein: Colourless → Pink in alkali — "Phenol turns Pink in base"
- Methyl orange: Red in acid → Yellow in alkali — "Methyl goes RED when angry (acidic)"
pH scale anchors: 0 = most acidic (stomach acid), 7 = neutral (pure water), 14 = most alkaline (bleach). Everything else falls between these reference points.
The three common acids: "HCl, H₂SO₄, HNO₃" — Hydrochloric, Sulfuric, Nitric. Mnemonic: "Hard Students Never fail" (HCl, H₂SO₄, HNO₃).
This memory aid covers Memory Aids within Acids and Alkalis for GCSE Chemistry. Revise Acids and Alkalis in Chemical Changes for GCSE Chemistry with 25 exam-style questions and 21 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 9 of 12 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Practice questions for Acids and Alkalis
Which ion do acids produce when dissolved in water?
Explain the difference between a strong acid and a concentrated acid.