October 20, 2021, 12:39:47 PM
Forum Rules: Read This Before Posting


Topic: Strength of Lewis acids/bases?  (Read 376 times)

0 Members and 1 Guest are viewing this topic.

Offline Meter

  • Full Member
  • ****
  • Posts: 232
  • Mole Snacks: +14/-3
  • Take what I say with a grain of salt
Strength of Lewis acids/bases?
« on: June 06, 2021, 08:28:12 AM »
How exactly do you quantify the strength of Lewis acids and bases? For Brønsted-Lowry acids/bases we can quantify their strength using pKa values. What about pH? For example, if I made a solution of AlCl3, would I get a reading on normal pH paper?

Surprisingly, this was not covered at all in our gen chem course.

Offline Orcio_Dojek

  • Full Member
  • ****
  • Posts: 318
  • Mole Snacks: +29/-2
Re: Strength of Lewis acids/bases?
« Reply #1 on: June 06, 2021, 11:25:51 AM »
There is no universal scale to compare strength of Lewis acid / base.

One base can form stronger bond with C(CH3)3+ and weaker with CH3+, other - in reverse. All depends on what compound is chosen.

Similiar - in nature - some elements (metals) are more attracted to oxygen, other to sulfur. So - they acidicity will depend whether it is measured towards O or S.

Offline Meter

  • Full Member
  • ****
  • Posts: 232
  • Mole Snacks: +14/-3
  • Take what I say with a grain of salt
Re: Strength of Lewis acids/bases?
« Reply #2 on: June 06, 2021, 02:28:50 PM »
Thanks. Is this data well defined? Like strength with relation to oxygen, suflur, etc.?

Offline Orcio_Dojek

  • Full Member
  • ****
  • Posts: 318
  • Mole Snacks: +29/-2
Re: Strength of Lewis acids/bases?
« Reply #3 on: June 06, 2021, 03:21:19 PM »
All scales are based on the reaction constant and presented in normal ("K") or logarythmic ("pK") scale.

Sponsored Links