Final answer:
Approximately 11.59 kcal of heat must be added to 0.61 kg of water to increase its temperature from 20°C to 39°C using the specific heat capacity of water and the temperature change.
Step-by-step explanation:
To calculate the amount of heat in kcal that must be added to 0.61 kg of water to raise its temperature from 20°C to 39°C, we must use the specific heat capacity of water and the temperature change. The specific heat capacity of water is typically 1 kcal/(kg·°C).
The change in temperature (ΔT) is the final temperature minus the initial temperature, which in this case is 39°C - 20°C = 19°C.
The heat (Q) required in kcal is calculated using the formula:
Q = m×specific heat capacity×ΔT
For water, this becomes:
Q = 0.61 kg × 1 kcal/(kg·°C) × 19°C
Q = 11.59 kcal
Therefore, 11.59 kcal of heat must be added to the 0.61 kg of water to raise its temperature from 20°C to 39°C.