Answer: The answer is S = 0.1528 cal/g °C
Explanation:
By the law of conservation of energy, energy is neither created nor destroyed.
So, energy lost by metal pieces is equal to the energy gained by water in the calorimeter.
Specific heat of water is 1 cal/g °C
⇒ heat energy Q = mSΔT, where m = mass of a substance
S = specific heat
ΔT = change in temperature
Now, the heat lost by metal piece, Q = 72×S×(96-31)
= 4680×S cal
Heat gained by water, Q = 130×1×(31-25.5)
= 715 cal
⇒ 4680×S = 715.
⇒ S = 0.1528 cal/g °C.