This exam tips covers Exam Tips for Specific Latent Heat within Specific Latent Heat for GCSE Physics. Revise Specific Latent Heat in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 11 of 12 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
💡 Exam Tips for Specific Latent Heat
🎯 Common Question Types:
- Calculate energy needed to change state using E = mL (2-3 marks)
- Explain why temperature stays constant during state change (3 marks)
- Explain why Lv is greater than Lf (3 marks)
- Interpret heating/cooling curve with latent heat sections (2-3 marks)
📝 Key Command Words:
- Calculate: Use E = mL, show each step, give correct units (J)
- Explain: Must link energy → bonds → kinetic/potential energy → temperature
- Compare: State values and explain the difference in terms of bond-breaking
- Suggest: May ask why steam is more dangerous than boiling water
⚠️ Common Mistakes to Avoid:
- Confusing E = mcΔT (temperature change) with E = mL (state change) — different equations for different situations
- Saying latent heat increases temperature — it does NOT; temperature stays constant
- Forgetting units — L is in J/kg, E is in J, m is in kg
- Saying Lf > Lv — vaporisation always needs more energy than fusion
Quick Check: How much energy is released when 0.5 kg of steam condenses to water at 100°C? (Lv = 2,260,000 J/kg)
E = m × L = 0.5 × 2,260,000 = 1,130,000 J (1130 kJ). This energy is released into the surroundings when bonds form during condensation — this is why steam releases so much more energy than hot water.
Practice questions for Specific Latent Heat
What is specific latent heat?
During a state change, energy is being supplied to a substance but the temperature does not change. Explain where this energy goes.