The distribution of chromium ion oxidation states—how many electron vacancies these ions have available ... [Cr 3+, with three electron vacancies] can accelerate corrosion in some cases, whereas ...

(aq) + 4{H_2}O\) Complex ion-electron equations can be written ... hydrogen ions), while the right hand side is 6+ (from the two chromium ions). The charge can be balanced by adding electrons ...