[DominicB]

Hi, I’d appreciate some help with writing a balanced equation for the reduction then oxidation of NiO in a cupric chloride etching solution.

Traditionally I am using the Cupric chloride as a highly effective and efficient etching solution for Cu. But I understand that the cupric chloride etchant can be effective when etching other metals too. But I’d like to understand the reaction that occurs.

When etching Cu I believe this to be correct. Feel free to correct me as well if this is incorrect.

First the copper reacts with the HCl in the etchant making CuO.

CuO + Cu+2Cl2  2Cu+1Cl

Then with additions of chlorine into the bath we complete the reaction of CuO into cupric chloride.

2Cu+1Cl + 2Cl-1  2Cu+2Cl2

But what happens instead when etching Nickel? I believe the same initial reaction occurs Ni reacts with HCl to form nickel oxide. But after that I do not know. As nickel is more reactive than copper does the nickel displace the copper to form Nickel chloride?

Thank you for reading and many thanks in advance to any responses.

[chenbeier]

In acidic copper chloride solution never Oxide will appear.
At least Cu2+ + e- => Cu+ is the main reaction . From this develop the other reaction.