A cube of aluminum has a temprature of 325K. it is placed in abeaker of cold wter. if the aluminum cools to 301K as the water absorbs 815.7 J of heat what is the mass of the cube

Answer 1

This is an application of the First Law of Thermodynamics as applied to a Calorimetry example, where heat lost (exothermic process) by the hot object (the aluminum) is equal to heat gained (endothermic) by the cold object (water in the beaker).

Mathematically, then, -qAL=qH20, where q=either heat evolved or gained

or -mcdeltaTAL=Heat gained by the water

so m=Heat gained by the water divided by the product of -cdeltaTAL

deltaT for the AL=325K-301K=-24K

One needs c (the specific heat for AL) to complete the calculation.