# Is there a relationship between acidity of the water solution and oxidation/reduction reactions?

What I want to know is if there is a relationship between the acidity of the water solution and redox reactions and if there is a relationship what favors the oxidation and what favors the reduction? Or does it depends on the reaction?

• Welcome to Chemistry.SE! Take the tour to get familiar with this site. Mathematical expressions and equations can be formatted using $\LaTeX$ syntax. || The pH definitely has an influence on a redox reaction, but I don't think it can be generalised. So, the answer to your last question would be: yes. – Martin - マーチン Dec 9 '19 at 16:19
• – Mithoron Dec 9 '19 at 17:32
• chemistry.stackexchange.com/questions/32509/… – Mithoron Dec 9 '19 at 17:41
• By medium, do you mean water solutions, or solvents themselves ( what includes other solvents than water, e.g acetic acid or liquid ammonia ) ? – Poutnik Dec 14 '19 at 2:56
• @Poutnik water solutions – Sujee0_0 Dec 15 '19 at 13:10

Fenton chemistry based on iron is definitely more reactive at lower $$\mathrm{pH}$$. This is due, in part, to speciation issues and associated solubility. Source: 'Effect of $$\mathrm{pH}$$ on Fenton and Fenton-like oxidation', by Jung YS, et al., at https://www.ncbi.nlm.nih.gov/pubmed/19278159.
However, the use of chelates (like EDTA) can expand the $$\mathrm{pH}$$ range of reactivity (see full paper at https://www.jstage.jst.go.jp/article/jwet/11/1/11_21/_pdf ).
There are other transition metals, like Copper, which appear to be active in a much wider $$\mathrm{pH}$$ range where the chemistry is referred to as Fenton-type. There is an old french patent on water purification (from microbes,...) based on copper ions ($$\ce{CuSO4}$$ in small amounts) and natural waters containing dissolved oxygen. Interestingly, the addition of EDTA is still recommended, but now as a means to TERMINATE the redox reaction at near-neutral $$\mathrm{pH}$$.