hey guys this is from pg88 of the success one hsc chemistry book. (Q1 e part iv)
Using the table of reduction potentials demonstrate with equations how the metal you have chosen prevents or slows the corrosion of iron in seawater.
i chose zinc.
according to the answers:
Cathode: 2H2O + 2e- --> 2OH- + H2 E = -0.83V
Anode: Zn --->Zn2+ + 2e- E = +0.76V
eventaully the zinc will oxidies away and the iron will begin to corrode
my problem is that the overall E nought value is negative.
ie E = -0.83 + 0.76 = -0.07V which means its not spontaneous.
does anyone agree that the cathode reaction should instead be
0.5O2 + H2O +2e- --> 2OH- E = 0.40V
giving the overall e nough value: E = 0.4 + 0.76 = 1.16V
thank in advanced
Using the table of reduction potentials demonstrate with equations how the metal you have chosen prevents or slows the corrosion of iron in seawater.
i chose zinc.
according to the answers:
Cathode: 2H2O + 2e- --> 2OH- + H2 E = -0.83V
Anode: Zn --->Zn2+ + 2e- E = +0.76V
eventaully the zinc will oxidies away and the iron will begin to corrode
my problem is that the overall E nought value is negative.
ie E = -0.83 + 0.76 = -0.07V which means its not spontaneous.
does anyone agree that the cathode reaction should instead be
0.5O2 + H2O +2e- --> 2OH- E = 0.40V
giving the overall e nough value: E = 0.4 + 0.76 = 1.16V
thank in advanced