Memory Aid: Double Arrow = Two-Way Traffic
This memory aid covers Memory Aid: Double Arrow = Two-Way Traffic within Reversible Reactions for GCSE Chemistry. Revise Reversible Reactions in Rates of Reaction for GCSE Chemistry with 20 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. 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.
Topic position
Section 9 of 12
Practice
20 questions
Recall
12 flashcards
🧠 Memory Aid: Double Arrow = Two-Way Traffic
The ⇌ symbol is your key visual reminder:
- → = one-way street (irreversible reaction)
- ⇌ = two-way road (reversible reaction, traffic flows both ways)
For the energy rule, remember the phrase: "FORWARD EXO = BACKWARD ENDO" — if energy is released going forward, it must be absorbed going backward. Think of a ball rolling down a hill (exothermic forward) — you need to push it back up the same hill (endothermic backward), using exactly the same energy it released coming down.
For copper sulfate: Blue has water, White has none — heat makes it white, add water makes it blue.
Keep building this topic
Read this section alongside the surrounding pages in Reversible Reactions. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Reversible Reactions
What does the symbol ⇌ mean when used in a chemical equation?
Explain the relationship between the energy changes in the forward and reverse reactions of a reversible reaction.
Quick Recall Flashcards
20 questions on Reversible Reactions — practise free
Instant marking, adaptive difficulty, and 12 spaced repetition flashcards. Free until your GCSEs.
Try PrepWise Free