Question
Steam at 100o C is passed into 20 g of water at 10o C. When the water acquires a temperature of 80o C, the mass of water present will be,
-
24 g
-
31.5 g
-
42.5 g
-
22.5 g
Solution
D.
22.5 g
Heat lost by the steam = heat gained by water
Let, m' be the amount of heat converted into water.
m' x L = ms 
m' x 540 = 20 x 1 x (80 - 10)
m' = 
Therefore, net amount of water = 20 + 2.5 = 22.5 g
