Will any kind soul please let me know what we went over in class yesterday? (Wednesday)

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Henri_de_Guzman_3L
Posts: 88
Joined: Thu Sep 27, 2018 11:25 pm

Will any kind soul please let me know what we went over in class yesterday? (Wednesday)

Postby Henri_de_Guzman_3L » Thu Dec 06, 2018 10:22 am

I missed Wednesday's class 12/5 and I was just wondering if anyone could help out and let me know what Dr. Lavelle went over. He was scheduled to go over "only 3 pages" and was going to finish the syllabus. I'd appreciate any help!

aisteles1G
Posts: 98
Joined: Thu Sep 27, 2018 11:15 pm

Re: Will any kind soul please let me know what we went over in class yesterday? (Wednesday)

Postby aisteles1G » Thu Dec 06, 2018 12:33 pm

We went over "Salts as Acids and Bases"
- Ions as acids: usually only Cations (+ charges) will donate H+ protons because they have more positive charges and therefore repel the H+ more so it's easier for them to donate protons than accept (be basic)
-Salts (any ionic compound) that contain an acid will lower the pH value of a solution
-I.e. Ammonium Chloride: NH4+Cl-, Cl- does not affect the pH (it is a strong acid meaning it'll form a weak base that is essentially neutral) so you leave it out of the net equation. The NH4+ though gives off H+ protons and is therefore and acid and becomes NH3.
The equation then ends up being: NH4+ + H20 > H30+ + NH3, this lowers the pH value of the solution since the H30+ increases the acidity (Proton concentration)

Acidic Salts: Small highly charged metal cations act as Lewis Acids (electron acceptors) to increase H30+, thereby increasing the acidity of a solution by dissolving in it. Common acidic salts come from cation transition metals that bond with negative charged ions (FeCl3) to form the salts.
-Hydrated metal cations will release the H+ proton to form H30+ in water
-Cations from groups 1 and 2 are weak Lewis acids and do not generate H30+, they have a neutral effect on the pH of the solution (do not raise/lower it)
-Very few anions act as acids because it is more difficult for negative ions to lose H+ since - attracts +, there are exceptions to this though such as HSO4- and H3PO4-

Ions as Bases: A salt containing a base will Raise the pH of a solution.
-Salts that contain the conjugate base of a weak acid will Raise the pH because a weak acid forms a strong conjugate base, it will do this by removing protons from water and generating OH-.

-You can tell whether a salt is acidic or basic by seeing if the ions that form it are strong acids or strong bases.

Polyprotic Acids and Bases: Compounds that can give off more than one proton ( Acid ) or accept more than one proton (base).
-a polyprotic acid will give off more than one H+ and therefore its conjugate bases will all accept more than 1 proton as well, so polyprotic acids make polyprotic conjugate bases and vice versa.

I think there was more but I left 5 minutes early so Im not sure, Hope this helps though!

Henri_de_Guzman_3L
Posts: 88
Joined: Thu Sep 27, 2018 11:25 pm

Re: Will any kind soul please let me know what we went over in class yesterday? (Wednesday)

Postby Henri_de_Guzman_3L » Thu Dec 06, 2018 2:08 pm

Thank you VERY much! This is perfect!


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