✔ 最佳答案
Energy needed to change 500.0 g of water from 50.0 °C to 100.0 °C
= m c ΔT
= (500.0 g) × (4.184 J/g°C) × [(100.0 - 50.0) °C]
Energy needed to change 500.0 g of water to vapor at 100 °C
= m Lv
= (500.0 g) × (2260 J/g)
Total energy needed
= (500.0 × 4.184 × 50 + 500.0 × 2260) J
= 1230000 J
= 1230 kJ