Could you explain why the iron (ii) carbonate re-dissolves and how this can be described as an acid/base reaction , by mixing FeSO4 and Fe2+ salts

Iron(II) carbonate is insoluble but in class you might not have seen any solid. The precipitate often redissolves because the iron(II) sulphate has acid added to it. Can you explain why the carbonate redissolves and how this can be described as an acid/base reaction


I know little to nothing about the topic and have done quite a bit of research but I can't find a simple definition that I am able to understand




Ferrons carbonate $\ce{FeCO3(s)}$ is like calcium carbonate $\ce{CaCO3}$ : it is soluble in carbonic acid with formation of the hydrogenocarbonate ion $\ce{HCO3^-}$in a reaction : $$\ce{FeCO3(s) + H2CO3 -> Fe^{2+} + 2 HCO3^- \tag{1}}$$ This means that $\ce{Fe(HCO3)2}$ is soluble in water.


$\ce{FeCO3(s)}$ can also be dissolved by the weak acidity produced by the hydrolysis of the $\ce{Fe^{2+}}$ ions coming from $\ce{FeSO4}$ in water, according to the two equations ($2$) and ($3$) : $$\ce{Fe^{2+} + H2O <=> [Fe(OH)]^+ + H^+ \tag{2}}$$
$$\ce{FeCO3 + H^+ -> Fe^{2+} + HCO3^- \tag{3}}$$


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