A calorimeter of water equivalent 20 g contains 180 g of water at 25
o
C. ‘m’ grams of steam at
100
o
C is mixed in it till the temperature of the mixure is 31
o
C. The value of ‘m’ is close to :
(Latent
heat of water = 540 cal g
–1
, specific heat of water = 1 cal g
–1
o
C
–1
)