QQuestion
Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C.
(Specific latent heat of ice = 336 J g−1, specific heat capacity of water = 4.2 J g−1 °C−1)
Exam-ready answer • 03 Mark
✓Answer
Mass (m) = 200 g
Specific heat capacity of water (c) = 4.2 J g-1 K-1
Specific latent heat of ice (L) = 336 J g-1
Total amount of heat energy required = ?
Heat energy taken by ice at 0° C to convert into water at 0° C
= m x L
= 200 × 336
= 67200 J
Heat energy taken by water to raise the temperature from 0° C to 100° C
= m x c x change in temperature
= 200 × 4.2 × (100 – 0)
= 200 × 4.2 × 100
= 84000 J
Total heat energy gained is
= 67200 + 84000
= 1,51,200 J
Hence, total amount of heat energy required = 1,51,200 J
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