Question 24
Change of State and VapoursHeat is supplied to a test tube containing 100g of ice at its melting point. The ice melts completely in 1 min. What is the power rating of the source of heat? (Latent heat of fusion of ice = 336 J g−1)
- A.336 W
- B.450 W
- C.560 W
- D.600 W
Show the answer and explanation
Answer: C (560 W)
Explanation
Heat needed = 100 × 336 = 33 600 J in 60 s. Power = 33 600 ÷ 60 = 560 W.