JAMB - Chemistry (1986 - No. 15)
Explanation
Iron (Fe) does not form a stable trioxocarbonate (IV) (also known as carbonate) in the sense of a stable, isolable compound. Carbonate ions (CO\(_3\) \(^{2-}\)) are typically found in compounds with other cations, not with iron in a stable, isolated form.
Aluminum (Al) does not form a stable trioxocarbonate (IV) (Al\(_2\)(CO\(_3\))\(_3\)) under normal conditions; it is an unstable compound, and when sodium trioxocarbonate (IV) is added to an aluminum salt solution, aluminum hydroxide precipitates and carbon dioxide is liberated.
Zinc (Zn) does form a stable trioxocarbonate (IV), which is commonly known as zinc carbonate (ZnCO\(_3\)). Zinc carbonate can be prepared by mixing a solution of a zinc salt (like zinc sulfate) with a solution of sodium carbonate.
Lead (Pb) does not typically form a stable trioxocarbonate (IV) (PbCO\(_3\)) under normal conditions, and it is not known to form a stable trioxocarbonate (IV).
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