How could you dissolve a coating of CaCO3(s) from a metal plate?


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> A metal plate has an unwanted coating of $\ce{CaCO3(s)}$. You must find a way to clean this metal plate without causing any scratches or abrasion. How might you dissolve the coating?
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I know I should find a substance that will dissolve the coating, and then soak the plate in it. How do I determine an appropriate substance?




It might take some time, but I would use vinegar.


The acid in vinegar is strong enough to dissolve the calcium carbonate, but it is not strong enough to dissolve metals (unless the metal reacts with water).


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I recommend [sulfamic acid](https://en.wikipedia.org/wiki/Sulfamic_acid) with formula $\ce{H3NSO3}$. The reaction is irreversible, no dangerous compound:


$$\ce{2 H3NSO3 + CaCO3 -> Ca(H2NSO3)2 + CO2 + H2O}$$


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