Question

a kilogram of aluminum metal and a kilogram of water are each warmed to 75 degree Celsius and placed in two identical insulated containers. one hour later, the two containers are opened and the temperature of each substance is measured. the aluminum has cooled to 35 degree Celsius while the water has cooled only to 66 degree Celsius. Explain this difference.

how to solve the question and answer Im having a hard time on this

Answer 1

The reason is that the water holds more heat than the aluminum.
Look up the specific heat of Al and water. I think Al is about 0.9 J/g*C and water is 4.184 J/g*C but you should confirm that. Now calculate the heat for each object.
q = mass Al x specific heat x T
q Al = 1000 g x 0.9 x 75C = 67,500 J
q H2O = 1000g x 4.184 x 75 = 313,800 J.
So the Al cools off faster since there is less heat to dissipate.

Answer 2

What is the specific heat of an unknown substance if 2000 J of energy are required to raise the temperature of 4 grams of the substance 5 degrees Celsius