Answer:- 2.92 kJ of heat is released.
Solution:- We have water at 100 degree C and it's going to be cool to 15 degree C.
So, change in temperature, = 15 - 100 = -85 degree C
mass of water, m = 8.2 g
specific heat of water, c =
The equation used for solving this type of problems is:
Let's plug in the values in the equation and solve it for q which is the heat energy:
q = (8.2)(4.184)(-85)
q = -2916.248 J
They want answer in kJ. So, let's convert J to kJ and for this we divide by 1000.
q = -2.92 kJ
Negative sign indicates the heat is released. So, in the above process of coiling of water, 2.92 kJ of heat is released.