16. Which forward reaction is a nonspontaneous process? (A)The expansion of a gas into a vacuum (B)(C)(D)None of these

18. Using the following standard reduction potentials calculate the standard cell potential for the galvanic cell reaction given below, and determine whether or not this reaction is spontaneous under standard conditions. Pb2+(aq) + 2 Fe2+(aq) → 2 Fe3+(aq)+ Pb(s) (A)E°= -0.90 V, nonspontaneous (B)E°= -0.90 V, spontaneous (C)E° = +0.90 V, nonspontaneous (D)E° = +0.90 V, spontaneous