Rusting of Magnesium: Equation & Experiment

  • Thread starter Thread starter tanya234
  • Start date Start date
  • Tags Tags
    Magnesium Rusting
Click For Summary

Discussion Overview

The discussion centers around the chemical processes involved in the rusting of magnesium, particularly in the context of an experiment where magnesium is used to protect iron from rusting in a sodium hypochlorite solution. Participants explore the chemical equations and mechanisms involved in this process.

Discussion Character

  • Technical explanation
  • Experimental/applied
  • Debate/contested

Main Points Raised

  • Tanya initiates the discussion by asking for the equation for the rusting of magnesium and describes her experiment where magnesium protects iron from rusting.
  • HONG KONG CHEM LOVER proposes a two-step reaction involving sodium hypochlorite and magnesium, suggesting that magnesium rusts instead of iron.
  • chem_tr challenges the accuracy of the equations provided, emphasizing the need for a redox reaction and outlining the oxidation of magnesium and the reduction of hypochlorite.
  • chem_tr also mentions the possibility of mixed products like Mg(OH)Cl and MgCl2 occurring during the reaction, depending on conditions.
  • chem_tr notes that magnesium oxide may form if the temperature is sufficiently high, leading to dehydration of magnesium hydroxide.
  • A later reply from HONG KONG CHEM LOVER acknowledges an oversight regarding the oxidation state of chlorine in hypochlorite.

Areas of Agreement / Disagreement

Participants express differing views on the accuracy of the proposed chemical equations and the products formed during the rusting of magnesium. There is no consensus on the correct representation of the reactions involved.

Contextual Notes

Participants highlight potential inaccuracies in the proposed equations and the complexity of the reactions, including the formation of various products under different conditions. The discussion reflects uncertainty regarding the complete and correct representation of the chemical processes.

tanya234
Messages
3
Reaction score
0
Hi I was wondering what would be the equation for the rusting of magnesium?

I did an experiment where an iron nail was covered by a strip of magnesium and was put into diluted NaOCl (diluted sodium hypochlorite solution). Apparently the magnesium protects the iron from rusting and hence rusts instead.



Thanks,

Tanya
 
Last edited:
Chemistry news on Phys.org
reply from HONG KONG CHEM LOVER

Hi I was wondering what would be the equation for the rusting of magnesium?

I did an experiment where an iron nail was covered by a strip of magnesium and was put into diluted NaOCl (diluted sodium hypochlorite solution). Apparently the magnesium protects the iron from rusting and hence rusts instead.

1st: NaOCl+ H2O <>(reversible) NaCl + 2OH-
2nd: Mg + 2OH->MgO (rust) +H2O
is it right, i am not sure
 
Hello

I am not sure the equations in the first reply is totally correct, the products are okay though; hypochlorite has 1+ valence on chlorine, but chloride consists 1- valence. So there has to be a redox chemistry, and therefore, a reduction step. The electrons must have released from magnesium atom, so magnesium atom must undergo an oxidation step. Let me summarize these below:

Mg ---> Mg2+ + 2e-
NaClO + 2e- + H2O ---> NaCl + 2OH-

Mg + NaClO + H2O---> Mg(OH)2 + NaCl

But magnesium oxide may also be produced if the temperature of the medium is sufficiently high to cause dehydratation (water removal):

Mg(OH)2 ---> MgO + H2O

PS: Please note that this approach is the ideal one; you may also predict that mixed products like Mg(OH)Cl and MgCl2 are likely to occur, but with a limited probability. Therefore, sodium hydroxide is another possible side product.

Regards
chem_tr
 
Last edited:
YES~ mine one is incorrect..

sorry, i hve overlooked the Cl in OCl is +1
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
35K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 10 ·
Replies
10
Views
18K
Replies
3
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 14 ·
Replies
14
Views
15K
  • · Replies 2 ·
Replies
2
Views
14K
  • · Replies 17 ·
Replies
17
Views
5K