5.When diagramming an electrochemical cell, be sure the electrons go from anode to cathode.
6.Be sure that for a galvanic cell, the cell potential is greater than 0.
7.Be sure to label the anode as (−) and the cathode (+) in a galvanic cell.
8.In cell notation, be sure to write anode, anode compartment, salt bridge, cathode com-
partment, cathode in this specific order.
9.When using a multiplier to equalize electron loss and gain in reduction half-cell poten-
tials, do notuse the multiplier on the voltage of the half-cell.
10.When using the Nernst equation, be sure to use the correct form of the reaction quo-
tient, products over reactants, and each concentration raised to the power the same as
the coefficient in the balanced reaction.Review Questions
Electrochemistry 251(A) There is no change in the voltage.
(B) The voltage becomes zero.
(C) The voltage increases.
(D) The voltage decreases, but stays positive.
(E) The voltage becomes negative.The following reaction takes place in a voltaic cell.Zn(s) +Cu^2 +(1 M) →Cu(s) +Zn^2 +(1 M)The cell has a voltage that is measured and found
to be +1.10 V.- What happens to the voltage when a saturated
ZnSO 4 solution is added to the zinc compartment
of the cell? - What happens to the cell voltage when the
copper electrode is made smaller? - What happens to the cell voltage when the
salt bridge is filled with deionized water instead
of 1 M KNO 3? - What happens to the cell voltage after the cell has
operated for 10 minutes? - MnO 4 −(aq) +H+(aq) +C 2 O 42 −(aq) →Mn^2 +(aq)
+H 2 O(l) +CO 2 (g)
What is the coefficient of H+when the above
reaction is balanced?
(A) 16
(B) 2
(C) 8
(D) 5
(E) 32- S 2 O 32 −+OH−→SO 42 −+H 2 O +e−
After the above half-reaction is balanced, which
of the following are the respective coefficients of
OH−and SO 42 −in the balanced half-reaction?(A) 8 and 3
(B) 6 and 2
(C) 10 and 2
(D) 5 and 2
(E) 5 and 1- How many moles of Pt may be deposited on the
cathode when 0.80 F of electricity is passed
through a 1.0 M solution of Pt^4 +?
(A) 1.0 mol
(B) 0.60 mol
(C) 0.20 mol
(D) 0.80 mol
(E) 0.40 mol- All of the following may serve as reducing agents,
EXCEPT:
(A) Mg
(B) Cs
(C) Fe^2 +
(D) MnO 4 −
(E) Br−Answer the following questions in 25 minutes. You may not use a calculator. You may use
the periodic table at the back of the book.Choose one of the following for questions 1–4.