How much heat energy is necessary to heat 1.0 kg of water from room temperature of 20 degrees Celsius to its boiling point?

Answer 1

The heat capacity of water is approximately 1 cal/g/°C or 1 kcal/kg/°C.

The boiling point of water is 100 °C so taking it from 20 °C boiling point means taking it to 100 °C - a change of 80 °C.

The indicated change would require adding about 80 kcal of energy.

From steam tables. the enthalpy of liquid water at 20 °C is 20.05 kcal/kg and the enthalpy at 100 °C is 100.09 kcal/kg - for a change of 80.04 kcal/kg or 80 kcal for 1.0 kg of water (taking into account that the original problem statement only provided values to 2 significant digits.)

Answer 2

You need:

Q= 4.18(Kj/kg.C) x 1 (Kg) x (98-20) = 326 Kj = 78 calories.

Answer 3

Specific heat capacity water - 4.187 kJ/kgK

4.187 kJ/kgK * 10'K * 1Kg = 41.87 Kj

Answer 4

How much heat must be added to 1.0 kg of water at 0 degrees Celsius to convert it into 1.0 kg of water at 100 degrees Celsius?

Answer 5

It is 416.666... kilojoules.