Properties Of Solids And Liquids Question 107
Question: Steam at 100ºC is passed into 1.1 kg of water contained in a calorimeter of water equivalent 0.02 kg at 15ºC till the temperature of the calorimeter and its contents rises to 80ºC. The mass of the steam condensed in kg is [IIT 1995]
Options:
A) 0.130
B) 0.065
C) 0.260
D) 0.135
Show Answer
Answer:
Correct Answer: A
Solution:
Heat is lost by steam in two stages (i)
for change of state from steam at 100ºC to water at 100ºC is m × 540 (ii)
to change water at 100ºC to water at 80ºC is m × 1 × (100 - 80), where m is the mass of steam condensed.
Total heat lost by steam is m × 540 + m × 20 = 560 m (cals)
Heat gained by calorimeter and its contents is = (1.1 + 0.02) × (80 - 15) = 1.12 × 65 cals. using Principle of calorimetery, Heat gained = heat lost - 560
m = 1.12 × 65, m = 0.130 gm
