is iron (III) carbonate a solid or (aq)?

It's a solid and it isn't soluble in water but is in acid.

Iron(III) carbonate, Fe2(CO3)3, is a solid compound.

To determine whether a compound is solid or aqueous (dissolved in water), you can refer to its solubility rules or consult reference materials like chemical databases.

In the case of iron(III) carbonate, it is insoluble in water. Iron(III) carbonate forms as a precipitate when a solution containing iron(III) ions (Fe3+) reacts with carbonate ions (CO32-). This solid precipitate does not dissolve in water, indicating that iron(III) carbonate is a solid.

It's essential to note that some compounds may exist in different forms (solid, liquid, or gas) under different conditions such as temperature and pressure. However, for most practical purposes, iron(III) carbonate is commonly encountered as a solid.