Acids and Bases

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Sona Hakobyan 3J
Posts: 45
Joined: Fri Sep 28, 2018 12:25 am

Acids and Bases

Postby Sona Hakobyan 3J » Sat Dec 08, 2018 3:57 pm

Can someone summarize the key things we should know about acids and bases for the final?

JT Wechsler 2B
Posts: 62
Joined: Fri Sep 28, 2018 12:16 am

Re: Acids and Bases

Postby JT Wechsler 2B » Sat Dec 08, 2018 4:09 pm

I think we need to the Lewis definition and the Bronsted definition. Also, we need to know strong acids and bases and how to calculate the pH. This would include using it for a neutralization reaction.

404905747
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

Re: Acids and Bases

Postby 404905747 » Sat Dec 08, 2018 4:10 pm

Is there any easy way to identify a strong acid or strong base besides just memorizing them?

Casandra
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

Re: Acids and Bases

Postby Casandra » Sat Dec 08, 2018 4:11 pm

Some basics are that there is a Lewis and a Bronsted definition to acids and bases. A lewis acid a species that accepts an electron pair(ex. BF3) and a lewis base is a species that donates and electron pair (ex. NH3). Whereas, a bronsted acid is a proton donor and donates a hydrogen ion (ex. HCl) and a bronsted base is a proton acceptor and accepts a hydrogen ion(ex. NaOH). We are dealing with bronsted acids and bases.
It would also be helpful to memorize the strong acids and strong bases.
Knowing to calculate pH=-log[H3O+] (same as pH=-log[H+]) and pOH=-log[OH-]
Knowing that the equilibrium constant is the concentration of products over the concentration of reactants--> Ka= [H+][A-]/[HA] in HA--> H+ + A-

Casandra
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

Re: Acids and Bases

Postby Casandra » Sat Dec 08, 2018 4:12 pm

404905747 wrote:Is there any easy way to identify a strong acid or strong base besides just memorizing them?

No, just memorize them, and if you have memorized them, then anything that is not a strong acid, is a weak acid.

aisteles1G
Posts: 117
Joined: Fri Sep 28, 2018 12:15 am

Re: Acids and Bases

Postby aisteles1G » Sat Dec 08, 2018 4:13 pm

I think you should know the differences between Arrenhenius, Bronsted and Lewis Acids and Bases and determine which compound in a reaction acts as which
Arrenhenius (in water) Acid : A compound that supplies the H+ in water
Arrenheius base: A compound that supplies the OH- in water.

Bronsted Acid: A proton (H+) donor
Bronsted Base: A proton (H+) acceptor

Lewis Acid: Any electron pair acceptor
Lewis Base: Any electron pair donor

Some equations to know: Neutralization reaction which is when an acid + (Metal+OH) react to form a salt and water molecules.
pH=-log(H30+) and the H30+ is the concentration of H+ ions in the solution. You get the concentration from the molarity.
pOH=-log(OH-) and OH- is again the concentration of hydroxides in the solution that you get from molarity.
Using 10^-pH will give you the concentration.
(h3O+)*(OH-)=1*10^-14

Also when determining if a compound will turn a solution acidic or basic remember that groups 1 and 2 are considered to be neutral atoms and therefore do not affect the pH of the solution. Metalloids with an oxygen also act as an amphoteric compound and I think it would be good to be able to tell if a molecule is an acid/base of neutral which you can tell because (H+)+nonmetal is usually acid and H- with another element is usually going to be basic.
Know that strong acids make weak conjugate bases and strong bases make weak conjugate acids (this will help you in determining how acid/basic a molecule is!)
Other than that I don't know what else might come up.
The final is not weighed towards the last few weeks either, it is evenly distributed he said so I wouldn't put all your focus on the new material since it might only be one or two questions on it.
Good luck studying!


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