Question

A steam at `100^@C` is passed into `1 kg` of water contained in a calorimeter of water equivalent `0.2 kg` at `9^@C` till the temperature of the calorimeter and water in it is increased to `90^@C`. Find the mass of steam condensed in `kg(S_(w) = 1 cal//g^@C, & L_("steam") = 540 cal//g) (EAM = 14 E)`.
A. 1
B. 0.1
C. 0.8
D. 0.135

Answer 1

Correct Answer - A
Heat required,
`Q_(1) = (1.1 + 0.02) xx 10^(3) xx (80 -15) = 72800` cal
Suppose m kg of steam is condensed and it also reaches to `80^(@)`C. Then heat rejected.
`Q_(2)` = mL + `mcDeltatheta`
`=m(540 xx 10^(3) + 20 xx 10^(3)`
`=560 xx 10^(3)`m
Equating `Q_(1)` and `Q_(2)` we get
m= 0.13 kg