How much heat is required to change 0.500 kg of water from a liquid at 50. â°c to vapor at 110. â°c?

Heat energy needed = 1243.45 kJ

Explanation:

We have

     heat of fusion of water = 334 J/g

     heat of vaporization of water = 2257 J/g

     specific heat of ice = 2.09 J/g·°C

     specific heat of water = 4.18 J/g·°C

     specific heat of steam = 2.09 J/g·°C

Here wee need to convert 0.500 kg water from 50°C to vapor at 110°C

First the water changes to 100°C from 50°C , then it changes to steam and then its temperature increases from 100°C to 110°C.

Mass of water = 500 g

Heat energy required to change water temperature from 50°C to 100°C

Heat energy required to change water from 100°C to steam at 100°C

Heat energy required to change steam temperature from 100°C to 110°C

Total heat energy required

Heat energy needed = 1243.45 kJ

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask