Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1]   Go Down

Author Topic: sacrificial anode  (Read 206 times)

0 Members and 1 Guest are viewing this topic.

magnus

  • Regular Member
  • ***
  • Mole Snacks: +0/-0
  • Offline Offline
  • Gender: Male
  • Posts: 18
sacrificial anode
« on: February 04, 2019, 09:55:45 PM »

Which of the following metals can behave as a sacrificial anode in an iron corrosion protection system (E ° (Fe2 + / Fe) = - 0.44 V).
(Ni2+/Ni)=-0.25 V
(Cu2+/Cu)=+0.34 V
(Pb2+/Pb)=-0.126 V
(Mn2+/Mn)=-1.18 V

I was thinking of Cu, but I'm not sure in semi-reaction
Logged

chenbeier

  • Full Member
  • ****
  • Mole Snacks: +41/-13
  • Offline Offline
  • Gender: Male
  • Posts: 398
Re: sacrificial anode
« Reply #1 on: February 04, 2019, 11:43:19 PM »

It can be only a metal with a redox potential less as -0,44 V. The metal normally is innoble like Magnesium, Zinc or Aluminium.
Logged

Enthalpy

  • Chemist
  • Sr. Member
  • *
  • Mole Snacks: +240/-54
  • Offline Offline
  • Posts: 2796
Re: sacrificial anode
« Reply #2 on: February 05, 2019, 05:36:10 AM »

I haven't seen aluminium in this role, despite it's cheaper than magnesium. Redox potential isn't the whole picture.

If someone has made experiments about galvanic corrosion, I'd gladly read the first-hand results. My single attempt told that corrosion couples change nothing, at least with the metal purity common in mechanical engineering.
Logged
Pages: [1]   Go Up
 

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.073 seconds with 23 queries.