The water and pot(/) have a temperature increase of 100-25 degrees C that is 75 degrees.. the formula Q=mass * SH* change in temperature can be used for both the water and the steel pot. Hence for steel pot Q=510 j/kg/degC*.5kg*75Deg C=19125 joule.. For water SH=4187 j/kg/C. QW= .45*4187*75=141311 joule. total heat (neglecting changes and losses to get the water to 100 deg C is 160436 joule or 160.4 kjoule. Note this does not boil the water it only raises the temperature to 100 degrees C. to boil the water requires approximately a futher 1250 kJ