Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Q4 Which of the following statements is true concerning the electrochemical cell

ID: 1013053 • Letter: Q

Question

Q4

Which of the following statements is true concerning the electrochemical cell described below at 25 degree C? Zn|Zn^2+ (0.768M)|| Zn^2+ (0.310 M)|Z_n Zn^2+(aq) + 2e^- rightarrow Zn(s), epsilon^0 = -0.76 V The cell reaction is spontaneous with a cell potential of 18.4 mV. The cell reaction is nonspontaneous with a cell potential of -11.7 mV The cell reaction is spontaneous with a cell potential of 11.7 mV The cell reaction is nonspontaneous with a cell potential of -18.4 mV. The cell reaction is nonspontaneous with a cell potential of -0.76 V.

Explanation / Answer

Second option is correct.

we have ,

Ecell = Ecell0 - RT/ nF lnQ

Where Ecell0 is zero because both electrode are of same half cell. therefore

Ecell = - (8.314 x 298 / 2 x 96500) x ln(0.768/0.31)

= -0.0117 V

therefore the cell reaction is nonspontaneous with a cell potential of - 11..7mV.