Question

In an emergency, it is sometimes the practice of medical professionals to immerse a patient who suffers from heat stroke in an ice bath, a mixture of ice and water in equilibrium at 0°C in order to reduce her body temperature.

(a) If a 77.9−kg patient whose body temperature is 42.5°C must have her temperature reduced to the normal range (36.0°C), how much heat must be removed?

(b) If she is placed in a bath containing 7.4 kg of ice, will there be ice remaining in the bath when her body temperature is 36.0°C. How much heat would the ice absorb before melting completely? How much ice would remain?

Answer 1

P.S :- Specific heat of body is not mentiond ib the question i am taking avg value to find the answers , = 3470 J/kg C

(a)
Q = m*C*ΔT
Q = 77.9 * 3470 * (42.5 - 36.0)
Q = 1757034.5 J

(b)
Latent heat of fusion of ice, L = 333.55 kJ/kg
m*L = 1757034.5
m * 333.55 * 1000 = 1757034.5
m = 5.26 kg

Ice would absorb all the heat of body and still be left !!
Amount of ice that will be left = 7.4 - 5.26 = 2.14 kg

Total amount of heat needed to completely melt the ice = 7.4 * 333.55 KJ = 2468.3 kJ