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Strong/weak acids & bases

Posted: Thu Jan 23, 2020 2:48 pm
by Fdonovan 3D
Are we going to have to know whether an acid or base is strong or weak just by its name or chemical formula? If so, how do we do know?

Re: Strong/weak acids & bases

Posted: Thu Jan 23, 2020 2:52 pm
by Brittney Hun 2C
You would just have to memorize the six strong acids H2SO4 Sulfuric Acid, HCl Hydrochloric Acid, HBr Hydrobromic Acid, HI Hydroiodic Acid, HNO3 Nitric Acid, HClO4 Perchloric Acid. Everything else is considered a weak acid. Strong bases have a group 1 or 2 metal attached to a hydroxide (OH-). Everything else is considered a weak base.

Re: Strong/weak acids & bases

Posted: Thu Jan 23, 2020 3:00 pm
by Justin Seok 2A
For the most part, in this section, we mostly work with weak acids and such since they are best suited for equilibrium type problems. However, it would probably be good to have a general idea of common strong acids just so you won't get blindsided if they come up on the test. However, it shouldn't be something that is very likely to come up on the test.

Re: Strong/weak acids & bases

Posted: Thu Jan 23, 2020 5:53 pm
by Kristina Rizo 2K
There is also a chart on page F75 in the seventh edition. It is in Fundamentals J, the table is Table J.1.

Re: Strong/weak acids & bases

Posted: Thu Jan 30, 2020 5:26 pm
by CameronDis2K
Yes, there's usually a pattern you can follow: anything with an OH- is usually a strong base (ex. KOH), and any compound preceded with an H and from the halogen group is usually a strong acid (HBr, HCl, etc.). But any compound with an NH3 is usually a weak acid, and others you can just memorize, like the weak acetic acid: CH3COOH.

Re: Strong/weak acids & bases

Posted: Fri Jan 31, 2020 9:12 pm
by Manav Govil 1B
You should be able to tell if something is a weak acid or base, based on if it can accept a proton or not. Also, you should have the strong acids memorized.

Re: Strong/weak acids & bases

Posted: Fri Jan 31, 2020 9:14 pm
by Sanjana Borle 2K
Strong acids are usually ones that give off protons easily, such as HF or HCl. Strong bases will give off OH- easily, such as NaOH.

Re: Strong/weak acids & bases

Posted: Fri Jan 31, 2020 9:41 pm
by Pablo 1K
Just focus on recognizing the strong acids and bases and I believe the weak ones will become noticeable easier.

Re: Strong/weak acids & bases

Posted: Sat Feb 01, 2020 3:08 pm
by Catherine Daye 1L
Yes, the best way is to memorize the strong acids and bases (there aren’t too many). In general, a strong acids start with H and strong bases end with OH. Everything else you can assume is weak

Re: Strong/weak acids & bases

Posted: Mon Mar 09, 2020 3:56 pm
by Mai V 4L
Does somwone have a chart/graphic they used to help memorize this?

Re: Strong/weak acids & bases

Posted: Tue Mar 10, 2020 5:54 pm
by Julia Holsinger_1A
How do you figure out the conjugate acid or base for a given base or acid?

Re: Strong/weak acids & bases

Posted: Tue Mar 10, 2020 9:32 pm
by WGaines_2E
We are usually given weak acids and bases on exams and the dissociation values for those you don't need to remember, they should be given

Re: Strong/weak acids & bases

Posted: Tue Mar 10, 2020 9:42 pm
by Nicholas_Gladkov_2J
Fdonovan 3D wrote:Are we going to have to know whether an acid or base is strong or weak just by its name or chemical formula? If so, how do we do know?


For the final, you should memorize the strong acids and strong bases are there are not that many.
Regarding weak acids and bases, given a scenario, and Ka and/or Kb, you should be able to know its pH, percent ionization, dissociation, etc.

Re: Strong/weak acids & bases

Posted: Wed Mar 11, 2020 7:14 pm
by Jessa Maheras 4F
CameronDis2K wrote:Yes, there's usually a pattern you can follow: anything with an OH- is usually a strong base (ex. KOH), and any compound preceded with an H and from the halogen group is usually a strong acid (HBr, HCl, etc.). But any compound with an NH3 is usually a weak acid, and others you can just memorize, like the weak acetic acid: CH3COOH.


These patterns are helpful!! I also find it helpful just to memorize.

Re: Strong/weak acids & bases

Posted: Wed Mar 11, 2020 10:45 pm
by Bryan Chen 1H
yea memorize them