The heat of vaporization of ethyl alcohol is about 200 cal/g. If 2 kg of this fluid were allowed to vaporize in a refrigerator, show that 5 kg of ice would be formed from 0°C water.

Solution 8P Step 1 During vaporization, ethyl alcohol will absorb some heat. The adsorbed byethyl alcohol is given by Q = m L e e,v e Here we have m is the mass and L is the latent heat of vaporization of ethyl alcohol. Now e e,v from the given problem we know that m e 5 kg = 5000 g L e,v= 200 cal/g So the required heat is 5 Q e (2000 g)(200 cal/g) = 4.0 × 10 cal. Step 2 Now heat released by ice during melting is given by Q i m L i i,m Where m is the mass and L is the latent heat of melting of ice. Now from the above equation i i,m we can write that,