Question

Calculate a. The heat that must be supplied to a 500.0 g copper kettle containing 400.0 g of water to raise its temperature from 22.0°C to the boiling point of water, 100.0°C. b. What percentage of the heat is used to raise the temperature of the water?

Answer 1

Explanation:

For Copper

dH copper = mCdT copper

(Specific Heat of copper=0.385 J/g C )  

dH = 500 g (0.385 J/g C) (78 C rise)

dH = 15,015 Joules

For Water

dH water =  m C dT water

(Specific Heat of copper=4.184 J/g-C)  

dH = 400 g (4.184 J/g-C) (78 C rise)

dH = 130,540 Joules

total heat = 15,015 + 130,540 = 145,555 Joules

Percentage for Water  

(130,540 Joules  / 145,555 Joules) x 100 = 89.7 %

If we consider that we have 3 Significant Figures,

then, the answers become ,

15.0 KJ must be added for Copper

130.5 KJ must be added for Water

and the total of 145 KJ must be added in the kettle with the water

89.7 %  of heat goes to the Water