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### Question 8.19 (Sixth Edition)

Posted: Mon Feb 11, 2019 12:30 am
Question: (a) Calculate 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 degrees Celsius to the boiling point of water, 100.0 degrees Celsius. (b) What percentage of the heat is used to raise the temperature of the water?

I'm having trouble with this question, can someone help me please? Thank you!

### Re: Question 8.19 (Sixth Edition)

Posted: Mon Feb 11, 2019 10:09 am
So with this question, you want to find q of both the copper and the water and add it together to find the total amount of heat supplied.
You know that q = mCdeltaT
q(copper) = (500 g)(0.38 J/gC)(100-22 C) = 14.82 kJ
q(water) = (400 g)(4.184 J/gC)(100-22 C) = 130.54 kJ
q(total) = 14.82 + 130.54 = 145 kJ

For part (b), you take the heat of the water and divide it by the total since that much is used to raise the temperature of the water. 130.5/145 = 90%.

### Re: Question 8.19 (Sixth Edition)

Posted: Mon Feb 11, 2019 11:45 pm
Where did you get 0.38 J/gC?

### Re: Question 8.19 (Sixth Edition)

Posted: Tue Feb 12, 2019 12:44 am
0.38 J/g C is the specific heat capacity of copper.