Question

Cryogenics has the potential to be useful in a variety of fields, including medicine. Suppose you have engineered a method to successfully deep-freeze and thaw human organs using liquid nitrogen without any freezing damage to the cells and tissue structure. How much heat must be removed from a liver (1.5 kg) to drop its temperature from 310 K to 180 K and freeze the tissue? For liquids and solids, heat capacity at constant pressure, Cp, is approximately equal to heat capacity at constant volume, Cv.

Answer 1

Step-by-step explanation:

It is known that the specific heat capacity of Liver
`(C_(p))` is 3.59 kJ
`kg^(-1).K^(-1)`

It is given that :

Initial temperature of Liver = Body temperature =
`37^(o)C` = 310 K

Final temperature of Liver = 180 K

Relation between heat energy, mass, and change in temperature is as follows.

Q =
`m * C_(p) * \Delta T`

Now, putting the given values into the above formula as follows.

Q =
`m * C_(p) * \Delta T`

Q =
`1.5 kg * 3.59 kJ/kg.K * (310 - 180) K`

= 700.05 kJ

Therefore, we can conclude that amount of heat which must be removed from the liver is 700.05 kJ.