Question

hi this seems simple but i cant figure it out.

If a 0.46 kg hot copper pan lost 9.8x103
J of heat as it cooled down to 54°C, what was its
original temperature?

I used the 24.44 j/molK for heat capacity, is not this one? found on wikipedia: copper

this is how i derive my equation...
-9.8x10^3=7.24mol(24.44j/molK)(327-x)

the answer is 77C but im getting 109.39C :( please help thanks

Answer 1

I used 0.385 J/g*C and came up with the same answer. You can prove that 109.39 is correct (although that's too many significant figures to use) this way.
109-54 = 55.39
55.39 x 0.385 J/g x 460 g = 980.9 J.
55.39 x 24.44 x (460/63.54) = 980.03 J.

Answer 2

thanks!!!! it was an exercise from study guide it just gave the answer not the solution. might be correction