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Acids and Bases A level Chemistry

Hi, I was a bit confused and wondering how would I know if a compound is amphoteric?
Also when a compound can behave as an acid and a base?
Original post by violetblue253
Hi, I was a bit confused and wondering how would I know if a compound is amphoteric?

Amphoteric = can react with both an acid and a base producing a salt and water (neutralisation).

The tendency is for metal oxides to be basic and non-metal oxides to be acidic. Oxides of metals that are close to the boundary metal/non-metal may be amphoteric. Also, there is a tendency for higher oxidation states oxides to be acidic. Hence, metal oxides in higher oxidation states may be amphoteric.
That said, it is easier just to learn some simple examples, eg aluminium oxide.

Amphiprotic = can act as both an acid and a base by providing hydrogen ions or reacting with hydrogen ions. A good example is the hydrogencarbonate ion or the water molecule.
Original post by charco
Amphoteric = can react with both an acid and a base producing a salt and water (neutralisation).

The tendency is for metal oxides to be basic and non-metal oxides to be acidic. Oxides of metals that are close to the boundary metal/non-metal may be amphoteric. Also, there is a tendency for higher oxidation states oxides to be acidic. Hence, metal oxides in higher oxidation states may be amphoteric.
That said, it is easier just to learn some simple examples, eg aluminium oxide.

Amphiprotic = can act as both an acid and a base by providing hydrogen ions or reacting with hydrogen ions. A good example is the hydrogencarbonate ion or the water molecule.

Thank you!!

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