Acid (Proton) Direct Attack on Iron

Shows direct proton-driven corrosion, where protons accept electrons from iron and evolve hydrogen gas. Illustrates how acids act as an accomplice to oxidation.

$$\mathrm{Fe}+2{\mathrm{H}}^{+}⟶{\mathrm{Fe}}^{2+}+{\mathrm{H}}_2(g)$$

Variables

Symbol	Meaning	Unit
Fe	metallic iron	atom
$H^{+}$	proton (hydrogen ion) from acid	ion
$F{e}^{2+}$	dissolved ferrous ion	ion
$H_2(g)$	hydrogen gas evolved	gas molecule

Worked example

One iron atom reacts with two protons to give one ferrous ion plus one hydrogen gas molecule.

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Part of The Blueprint of Water