Solution:
Given:
Change in entropy of the system, ΔS = 12J/K
Temperature of the system, [tex]T_{o}[/tex] = 250K
Now, we know that the change in entropy of a system is given by the formula:
ΔS = [tex]\frac{\Delta Q}{T_{o}}[/tex]
Amount of heat added, ΔQ = [tex]\Delta S\times T_{o}[/tex]
ΔQ = 3000J