Question

Balance the following skeleton ionic reaction, and calculate E°cell to decide whether the reaction is spontaneous: Ag(s) + Cu2+ (aq) LaTeX: \longrightarrow⟶ Ag+ (aq) + Cu(s) Enter a number so 1, 2, 3 etc E°cell = spontaneous? enter yes or no (MTS 3/3/2019)

Answer 1

Answer:

Explanation:

Electrochemical cell is composed of 2 half cells, one where reduction reaction takes place which is the cathode and the other is where oxidation reaction takes place.

Reduction reaction

Cu2+(aq) + 2e- ---> Cu(s)

E° = 0.34 V

Oxidation reaction

2Ag(s) --> 2Ag+(aq) + 2e-

E° = -0.80 V

Combining both equations,

2Ag(s) + Cu2+ (aq) ⟶ 2Ag+ (aq) + Cu(s)

Standard eletrode potential of the cell, E°cell = E°cath - E°anode

= 0.34 - (-0.80)

= +1.14 V.

If the value of E°cell is positive, then the reaction is spontaneous, and it will occur as written under standard conditions; it will, however, not proceed spontaneously in the opposite direction.

Answer 2

Answer:

2Ag(s) + Cu^2+(aq) ----------> 2Ag^+(aq) + Cu(s)

Explanation:

Ag(s)/Ag^+ (aq) is the anode as shown while Cu^2+(aq)/Cu^2(s) is the cathode.

E°cell= E°cathode -E°anode= 0.34 -0.80= -0.5V

The cell is not spontaneous as written because E°cell is negative. This implies that the electrodes of the cell must be interchanged to make the cell spontaneous.