Reactions of Alkali Metals
Part of Group 1: Alkali Metals · GCSE GCSE Chemistry revision
This key facts covers Reactions of Alkali Metals within Group 1: Alkali Metals for GCSE Chemistry. Revise Group 1: Alkali Metals in Atomic Structure for GCSE Chemistry with 22 exam-style questions and 20 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 6 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 6 of 13
Practice
22 questions
Recall
20 flashcards
⚗️ Reactions of Alkali Metals
With WATER:
alkali metal + water → metal hydroxide + hydrogen
Example: 2Na + 2H₂O → 2NaOH + H₂
- Lithium — fizzes gently, moves slowly
- Sodium — fizzes vigorously, melts into a ball, darts around
- Potassium — fizzes violently, lilac flame, may explode
With OXYGEN:
alkali metal + oxygen → metal oxide
Example: 4Li + O₂ → 2Li₂O
This is why they're stored under oil — to prevent reaction with air!
With CHLORINE:
alkali metal + chlorine → metal chloride
Example: 2Na + Cl₂ → 2NaCl
Also: 2Li + Cl₂ → 2LiCl and 2K + Cl₂ → 2KCl
Alkali metals react vigorously with chlorine gas to produce white crystalline metal chloride salts. The reaction demonstrates the same electron transfer principle as the reaction with water: the alkali metal loses its 1 outer electron to become a +1 ion, while each chlorine atom gains 1 electron to become a -1 ion (Cl⁻). Sodium chloride (common table salt) is the most familiar product. The reactivity with chlorine follows the same trend as reactions with water and oxygen — potassium reacts most vigorously, lithium least vigorously.
Quick Check: Write a word equation for the reaction of potassium with water.
potassium + water → potassium hydroxide + hydrogen. The symbol equation is: 2K + 2H₂O → 2KOH + H₂
Keep building this topic
Read this section alongside the surrounding pages in Group 1: Alkali Metals. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Group 1: Alkali Metals
How many electrons do alkali metals have in their outermost shell?
Explain why potassium is more reactive than sodium when it reacts with water.
Quick Recall Flashcards
22 questions on Group 1: Alkali Metals — practise free
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