JEE Main20198 Apr 2019Morning ShiftPhysicsThermal Properties of MatterActual
A thermally insulated vessel contains 150 g of water at 0 ° C . Then the air from the vessel is pumped out adiabatically. A fraction of water turns into ice and the rest evaporates at 0 ° C itself. The mass of evaporated water will be closest to: (Latent heat of vaporization of water = 2.10 × 10 6 J k g - 1 and Latent heat of Fusion of water = 3.36 × 10 5 J k g - 1 )
Options
- A35 g
- B20 g
- C130 g
- D150 g
Correct answer
B. 20 g
Step-by-step solution
Suppose m grams of water evaporate. Then, heat required Δ Q r e q = m L v Mass that converts into ice = 150 - m Heat released in the process, Δ Q r e l = 150 - m L f Now, Δ Q r e l = Δ Q r e q 150 - m L f = m L v m L f + L v = 150 L f m = 150 L f L f + L v m = 20 g