Question

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

Answer 1

Heat energy needed = 1243.45 kJ

Step-by-step 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

`H_1=mC\Delta T=500* 4.18* (100-50)=104.5kJ`

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

`H_2=mL=500* 2257=1128.5kJ`

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

`H_3=mC\Delta T=500* 2.09* (110-100)=10.45kJ`

Total heat energy required

`H=H_1+H_2+H_3=104.5+1128.5+10.45=1243.45kJ`

Heat energy needed = 1243.45 kJ