Question

1. a) Mark each sentence as (T)rue or (F)alse

- ( ) If enthalpy change for a reaction is zero, then ∆G° equals to zero.

- ( ) If ∆G° is negative, reactants are favored.

- ( ) If a reaction has a high negative ∆G° it will proceed faster than a reaction which has a lower negative ∆G°   (like – 90 kJ ∆G° reaction faster than -30 ∆G° reaction).

- ( ) When change in enthalpy is positive (endothermic reaction) for a system you feel cold because it is taking heat from your skin.

b) Living organisms grow, they increase in complexity and decrease in entropy. How does this relate to the second law of thermodynamics?

Answer 1

(A)

(1) ∆G=∆H-T∆S------------------------ FOR ISOTHERMAL PROCESS (∆T=0)

IF ∆H=0 THEN ∆G=-T∆S -----FALSE

(2)  ∆G= NEGATIVE, THEN PROCESS IS SPONTANEOUS

IF ∆G IS NEGATIVE THEN PRODUCT IS FAVORED ---------- FALSE

(3)  ∆G= NEGATIVE, THEN PROCESS IS SPONTANEOUS

high negative ∆G° it will proceed faster TRUE

(B)

ENTROPY CAN BE THOUGHT AS "DEGREE OF DISORDER" , WHEN A LIVING ORGANISM GROWS CELLS COMBINE TO FORM TISSUES, TISSUES COMBINE TO FORM ORGANS AND ORGANS COMBINE TO FORM BODY PARTS. SO THE LIVING STRUCTURE BECOMES MORE ORDERED. IN THIS SENSE WE CAN SAY ENTROPY DECREASES WHEN LIVING ORGANISM GROWS. SECOND LAW SAYS ENTROPY OF UVIVERSE(SYSTEM+SURROUNDING) IS ALWAYS INCREASING, EVEN THOUGH ENTROPY DECREASES WHEN LIVING THING GROWS BUT IT IS ACCUMULATION OF ENERGY WHICH IN TURN INCREASES THE ENTROPY OF THE SURROOUNDING BY INTERACTING WITH IT. THAT'S WHY WE SAY ENTROPY INCREASES AT THE EXPENSE OF ENERGY.