Q.

An amount of ice of mass 10–3 kg and temperature –10°C is transformed to vapour of temperature 110°C by applying heat. The total amount of work required for this conversion is, (Take, specific heat of ice = 2100 J kg–1 K–1, specific heat of water = 4180 J kg–1 K–1, specific heat of steam = 1920 J kg–1 K–1, Latent heat of ice = 3.35×105 J kg–1 and Latent heat of steam = 2.25×106 J kg–1)          [2025]

1 3022 J  
2 3043 J  
3 3003 J  
4 3024 J  

Ans.

(2)

First, Ice at –10°C →△Q1 Ice at 0°C →△Q2 Water at 0°C. Then, Water at 0°C →△Q3 Water at 100°C →△Q4 Vapour at 100°C →△Q5 Vapour at 110°C

△Q1=m×SI×△T=10–3×2100×10=21 J

△Q2=m×Lf=10–3×3.35×105=335 J

△Q3=m×Sw×△T=10–3×4180×100=418 J

△Q4=m×Lv=10–3×2.25×106=2250 J

△Q5=m×Sv×△T=10–3×1920×10=19.2 J

△Qnet=3043.2 J