Answer:
3.1 × 10⁷ J
Explanation:
The total heat required is the sum of the heats required in each stage.
1) Solid: from -60°C to 0°C.
Q₁ = c(s) × m × ΔT = (2090 J/kg.°C) × 10 kg × (0°C - (-60°C)) = 1.3 × 10⁶ J
where,
c(s): specific heat of the solid
m: mass
ΔT: change in the temperature
2) Solid to liquid at 0°C
Q₂ = Qf × m = (3.3 × 10⁵ J/kg) × 10 kg = 3.3 × 10⁶ J
where,
Qf: latent heat of fusion
3) Liquid: from 0°C to 100°C
Q₃ = c(l) × m × ΔT = (4186J/kg.°C) × 10 kg × (100°C - 0°C) = 4.2 × 10⁶ J
where,
c(l): specific heat of the liquid
4) Liquid to gas at 100 °C
Q₄ = Qv × m = (2.26 × 10⁶ J/kg) × 10 kg = 2.26 × 10⁷ J
where,
Qv: latent heat of vaporization
Total heat
Q₁ + Q₂ + Q₃ + Q₄
1.3 × 10⁶ J + 3.3 × 10⁶ J + 4.2 × 10⁶ J + 2.26 × 10⁷ J = 3.1 × 10⁷ J
