How many kilojoules are required to warm 25.0 g of water from 75.0 C to 100.0 C and convert it to steam at 100.0 C? The heat of vaporization of water is 2260 joules/g, and the the specific heat of water is 4.184 joules/g?

1 Answer
Jul 6, 2017


You have to add the energy required for the heating up and the energy for the vapourizing.


To heat 1 gram of water from 75 to 100 deg C means a temperture rise of 25 deg C.
Heat required: #25xx4.184=104.6J//g#
To vapourize that same gram: #2260J//g#

So total energy required to heat up and vapourize 1 gram:

Multiply this by the mass of the water:
(rounded to 3 SF)