Acids and Bases [ENDORSED]
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 20
- Joined: Fri Sep 29, 2017 7:04 am
-
- Posts: 53
- Joined: Sat Jul 22, 2017 3:00 am
Re: Acids and Bases [ENDORSED]
Weak acids create "strong" conjugate bases because their dissociation reaction (the reaction of it releasing an H+ ion) is not favored. If you take HNO2 (nitrous acid) as an example, the reaction for HNO2 to produce a conjugate base would be as follows:
HNO2 = H+ + NO2-
In this case, NO2- is the conjugate base.
Because HNO2 is a weak acid, not a lot of it dissociates. In other words, it is favored that HNO2 remains together as a molecule and does not release H+ ions. Some HNO2 molecules do dissociate but most do not. This means that NO2- is a strong base because the back reaction (the reaction that causes it to become HNO2 again) is favored. Keep in mind this definition of "strong base" doesn't apply in the "bases that dissociate completely to release OH-" sense of the term, it just means that relative to HNO2 as a weak acid, NO2- is a strong base.
HNO2 = H+ + NO2-
In this case, NO2- is the conjugate base.
Because HNO2 is a weak acid, not a lot of it dissociates. In other words, it is favored that HNO2 remains together as a molecule and does not release H+ ions. Some HNO2 molecules do dissociate but most do not. This means that NO2- is a strong base because the back reaction (the reaction that causes it to become HNO2 again) is favored. Keep in mind this definition of "strong base" doesn't apply in the "bases that dissociate completely to release OH-" sense of the term, it just means that relative to HNO2 as a weak acid, NO2- is a strong base.
-
- Posts: 25
- Joined: Fri Sep 29, 2017 7:04 am
-
- Posts: 59
- Joined: Fri Sep 29, 2017 7:04 am
- Been upvoted: 1 time
Re: Acids and Bases
A strong acid is an acid in which almost all of the molecules are deprotonated in solution. A weak acid is an acid in which only a small fraction of the molecules become deprotonated in solution.
-
- Posts: 76
- Joined: Fri Sep 29, 2017 7:07 am
Re: Acids and Bases
there is a list of strong acids, if it is not one of those, it is considered weak. the list of strong acids include HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4
-
- Posts: 59
- Joined: Fri Sep 29, 2017 7:04 am
- Been upvoted: 1 time
-
- Posts: 76
- Joined: Fri Sep 29, 2017 7:07 am
Re: Acids and Bases
I honestly don't know, but I doubt it. I was told to memorize them by my plf. There's also a list of strong bases. LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, and Ba(OH)2
-
- Posts: 25
- Joined: Fri Sep 29, 2017 7:04 am
-
- Posts: 67
- Joined: Fri Sep 29, 2017 7:05 am
Re: Acids and Bases
Everything that isn't a strong base or strong acid (which were listed above) is considered weak.
Return to “Conjugate Acids & Bases”
Who is online
Users browsing this forum: No registered users and 8 guests