Molecular systems tend to move spontaneously to a state where the energy can be distributed in the most number of ways. The quantitative measure of this movement toward maximum dissipation of energy is called entropy and is denoted by the symbol S. As a state function, entropy change, AS, depends only on initial and final states. AS has a positive value when energy can distributed in more ways and a negative value when energy becomes concentrated. The following conditions usually result in an increase in entropy: • Part A Predict the sign of the entropy change, A,s", for each of the reaction displayed. • a change of phase: solidliquidgas an increase in the number of gas molecules, or Drag the appropriate items to their respective bins. > View Available Hint(s) Although the sign of entropy change can be predicted as described above, actual value of A,S" for a chemical process, must be calculated form the absolute entropy values, S", of the reactants and products. Reset Help A,s° = s" (products) – S" (reactants) A : Pb2+ (ag) + 2CI-(ag)→PbCl2B : Ca(OH)2(s)»CaO(s) + H20 C: 2NH3(g)N2(g) + 3H2(g)D: 2H2(9) + O2(g)→2H20() E: C;H12(9) + 802(9)5CO2(s)I;QG→2(9) Positive Negative