CHEMISTRY COMMUNITY

Hi,
Is it correct to say that all amphiprotic substances are amphoteric? If so, what are some compounds that are amphoteric but not amphiprotic?

Hi! I think the way we have to think about it is that if a substance is amphiprotic then it also has to be amphoteric.

Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. However, ZnO is amphoteric but not amphiprotic because it does not have protons to donate but it can act as an acid or a base.

What does the term polyprotic mean? Can a molecule be both polyprotic and amphiprotic?

Brynne Burrows 3K wrote:Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. However, ZnO is amphoteric but not amphiprotic because it does not have protons to donate but it can act as an acid or a base.

How can ZnO act as an acid if it does not have protons to donate? Is it because it acts as a Lewis acid and can accept electrons?

So are amphoteric and amphiprotic the same thing?

ALegala_3I wrote:What does the term polyprotic mean? Can a molecule be both polyprotic and amphiprotic?

Polyprotic means an acid that can give more than one proton

Rebecca Epner 4A wrote:

Brynne Burrows 3K wrote:Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. However, ZnO is amphoteric but not amphiprotic because it does not have protons to donate but it can act as an acid or a base.

How can ZnO act as an acid if it does not have protons to donate? Is it because it acts as a Lewis acid and can accept electrons?

I think it can act as an acid in the since that it can react with a base. For example, ZnO + 2NaOH -> Na2ZnO2 + H2O

JChen_3C wrote:

Rebecca Epner 4A wrote:

Brynne Burrows 3K wrote:Amphiprotic means that a substance can both accept and donate a proton or H+. Amphoteric means that a substance can act as both an acid and a base. All amphoteric substances are amphiprotic because if a molecule can either donate or accept a proton, that means it can act as both an acid or a base. However, ZnO is amphoteric but not amphiprotic because it does not have protons to donate but it can act as an acid or a base.

How can ZnO act as an acid if it does not have protons to donate? Is it because it acts as a Lewis acid and can accept electrons?

I think it can act as an acid in the since that it can react with a base. For example, ZnO + 2NaOH -> Na2ZnO2 + H2O

Sorry Im kind of confused, if it doesn't have protons to donate how does it interact to begin with?

polyprotic means an acid can give more than one proton and its conjugate base can accept more than one proton.