5 g of steam at 100°C is passed into a calorimeter. Its contents warm from 32°C to 40°C. Find the water equivalent of the calorimeter and contents (g). Take latent heat of steam as 540 cal/g.
Physics · Mixed Chapter
JEE Main Practice

Question

5 g of steam at 100°C is passed into a calorimeter. Its contents warm from 32°C to 40°C. Find the water equivalent of the calorimeter and contents (g). Take latent heat of steam as 540 cal/g.

G1 Physics · Accepted Answer

Step 1: Each gram of steam condenses at 100°C, releasing L = 540 cal/g. Step 2: Condensed water cools from 100°C to 40°C, releasing 1 × 60 = 60 cal/g. Step 3: Total heat released = 5(540 + 60) = 3000 cal. Step 4: If water equivalent is M, it absorbs M(40 − 32) = 8M cal. Thus M = 3000/8 = 375 g.