The temperature of 100 gm of water is to be raised from²4°C to 90°C by adding steam to it. Calculate the mass (in gm) of the steam required for this purpose.
Physics · Thermodynamics
JEE Mains

Question

The temperature of 100 gm of water is to be raised from²4°C to 90°C by adding steam to it. Calculate the mass (in gm) of the steam required for this purpose.

G1 Physics · Accepted Answer

Apply energy conservation. Sensible heat is Q=mcΔT and phase-change heat is Q=mL. Heat lost by hotter parts equals heat gained by colder parts. Substituting the given values gives 12.