Recognizing Amphoteric Substances
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 99
- Joined: Wed Sep 30, 2020 9:43 pm
Recognizing Amphoteric Substances
Can someone please walk me through how to recognize or determine if a substance is amphoteric?
-
- Posts: 107
- Joined: Wed Sep 30, 2020 9:56 pm
- Been upvoted: 1 time
Re: Recognizing Amphoteric Substances
The substance you are looking at must be able to accept H+ (one indicator that it can accept another proton is a negative charge) and donate H+ as well, meaning that H+ would have to be somewhere in the formula. For example, looking at H2PO4-, it can both give away a H+ to become PO42-, or accept another H+ and become H3PO4. On the other hand, something like CO32- cannot donate any H+ so it couldn't be amphoteric.
-
- Posts: 100
- Joined: Wed Sep 30, 2020 9:31 pm
Re: Recognizing Amphoteric Substances
Hi! There are also some amphoteric substances along the metalloid line.
-
- Posts: 104
- Joined: Wed Sep 30, 2020 9:31 pm
Re: Recognizing Amphoteric Substances
I don't really know how to figure out if a substance is amphoteric, but, I think that the only ones we need to know are:
BeO, Al2O3, Ga2O3, SaO2, Sb2O5, and PbO2.
BeO, Al2O3, Ga2O3, SaO2, Sb2O5, and PbO2.
-
- Posts: 100
- Joined: Wed Sep 30, 2020 9:51 pm
Re: Recognizing Amphoteric Substances
Kayla Booker 1C wrote:Can someone please walk me through how to recognize or determine if a substance is amphoteric?
Amphoteric compounds are ones that can act as both an acid or a base depending on the situation. So, as someone above said, a great way to determine if something is amphoteric is to see if it can accept an H+ and donate an H+ to solution. Usually, if a compound has an H in it but also has a negative charge, that is an alright indicator that it is amphoteric.
Upon looking into it a little more, it seems that the metal oxides (those that someone else listed) that are amphoteric are all of a pretty medium-ranged electronegativity on the metal, so I would say those oxides with a metal closer to the right side of the periodic table are more likely to be amphoteric in case you forget one from the list.
-
- Posts: 100
- Joined: Wed Sep 30, 2020 10:01 pm
Re: Recognizing Amphoteric Substances
Oxides of the elements in and close to the diagonal line of metalloids are usually an indication of amphoteric oxides.
-
- Posts: 127
- Joined: Wed Sep 30, 2020 9:51 pm
Re: Recognizing Amphoteric Substances
For the purposes of the class, I believe we need to understand that water has amphoteric properties, and the metalloids are amphoteric.
-
- Posts: 105
- Joined: Wed Sep 30, 2020 9:48 pm
- Been upvoted: 2 times
Re: Recognizing Amphoteric Substances
The definition of amphoteric is a species that is able to act as both a base and acid, which means it should be able to accept and donate a proton when need be.
Ex: H2O can become H3O+ or OH- so it is amphoteric
Ex: H2O can become H3O+ or OH- so it is amphoteric
-
- Posts: 100
- Joined: Wed Sep 30, 2020 10:00 pm
Re: Recognizing Amphoteric Substances
Amphoteric substances need to be able to accept and donate protons. A negative charge is a good indicator that a Hydrogen can be accepted, but if the molecule already has a hydrogen then the molecule can also donate a proton. This isn't a rule for all amphoteric substances but it can be helpful.
Return to “Amphoteric Compounds”
Who is online
Users browsing this forum: No registered users and 4 guests