Question

What is the change in entropy when 100 gm of water is heated from 27oc to 87oc?

Answer 1

when 100 gm of water is heated from 27oc-87oc,the change in entrepoy is 418.5 In(1.2)

Answer 2

Entropy change, ΔS = Cp ln(T2/T1)
Cp = Specific heat of water = 4.2 KJ/kg-K = 4.2 J/g-K
T2 = 273+87 = 360K
T1 = 273+27 = 300K
ΔS = 4.2*ln(360/300) = 4.2ln(1.2) J/g-K
For 100 g of water 4.2ln(1.2) * 100 = 420ln(1.2) J/K