Practice question · Estimate
Ice absorbs heat while melting at a constant 0 °C. If 100 g of ice at 0 °C sits in a drink, roughly how much energy does it soak up just by melting, in kilojoules? (Latent heat of fusion ≈ 334 J/g.)
Estimate on a scale from 0 kJ (0) to 60 kJ (60).
Hints
- Melting energy = mass × latent heat; the temperature does not budge until the last crystal is gone.
- J.
Show the answer
33.4 (answers within ±4 count)
Why
About 33 kJ, enough to cool 100 g of water by a huge 80 °C. Latent heat is energy spent dismantling the crystal, not raising temperature, which is why ice cools drinks so much better than cold water of the same mass.
Practise States of matter and phase behaviour
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