how much energy (in J) was made unavailable for useful work as a result?

Question

An irreversible process takes place by which the entropy of the universe increases by 1.66 J/K. If the temperature of the environment in which the process occurred is 230 K, how much energy (in J) was made unavailable for useful work as a result?

Answer 1

Hi Emma L.,

deltaG = deltaH - TdeltaS . So you can see that TdeltaS (that's a product of the two values) is the correction to apply. Remember that T is in K, not C ! (DeltaG is free energy, which tells you if/how_much a reaction will "go". If it won't "go", then you can't get useful work from it.)

-- Cheers, -- Mr. d.