Question

How many Kcal of heat is needed to increase the temperature of 800 grams water having

temperature change of 75 ᵒC.

Answer 1

1 cal is the energy required to increase the temperature of 1 g of water by 1°C. Therefore, to increase the temperature of 800 g of water by 1°C, we need 800 cal, to increase this mass of water by 75°C, we need

$$Q=800·75=60000\text{ cal, or 60 kcal.}$$