Answer:
Explanation:
Heat is taken away from coffee by evaporating water in the process of turning into vapor. So coffee becomes cold
Heat taken up by water to evaporate
mass x latent heat
= 2 x 540 Calorie.
= 1080 Cals
If t be the decrease in temperature of coffee
heat given out
= mass x specific heat of water x fall in temperature
250 x 1 x t
heat loss = heat gain
250 t = 1080
t = 4.32 °C.
Final temp = 90 - 4.32 = 85.68 °C.
