Which process absorbs the greatest amount of heat?

a. the cooling of 10 g of liquid water from 100°C to 0°C.

b. the heating of 10 g of liquid water from 0°C to 100°C.

c. the freezing of 10 g of liquid water the melting of 10 g of ice.

d. the condensation of 10 g of gaseous water.

b. the heating of 10 g of liquid water from 0°C to 100°C.

Explanation:

Hello,

In this case, we must notice a., c. and d. processes are not actually absorbing heat but releasing it since cooling, freezing and condensation are processes with negative heat sign since matter changes from a state of more energy to a state of less energy. We can prove this by realizing that freezing enthalpy of water is - 6.00 kJ/mol, condensation enthalpy of eater is - 40.8 kJ/mol and a change of temperature from 100 °C to 0 °C is negative.

In such a way, the only process absorbing heat is b. the heating of 10 g of liquid water from 0°C to 100°C since energy must be added to the system, or absorbed by it in order to attain the heating.

Regards.