chem - acids and bases

Question 1

Describe each:

Arrhenius Definition of Acids & Bases

Bronsted-Lowry acid & base

Lewis acid & base

Answer 1

Arrhenius acid— produces H+ ions (Ex. HCl à H+ + Cl-)
Arrhenius base— produces OH- ions (Ex. NaOH à Na+ + OH-)
Bronsted-Lowry Definition of Acids and Bases

Bronsted-Lowry acid—a proton (H+) donor (Ex. HNO3 + H2O ⇌ H3O++ NO3-)
Bronsted-Lowry base— a proton (H+) acceptor (Ex. HNO3 + H2O ⇌ H3O++ NO3-)
Lewis Definition of Acids and Bases

Lewis acid— accepts a pair of electrons (Ex. BF3 + NH3 ⇌ BF3NH3)
Lewis base— donates a pair of electrons (Ex. BF3 + NH3 ⇌ BF3NH3)

Question 2

higher pka and pkb means stronger/weaker acid/base?

Answer 2

Higher pka = WEAKER acid
- acids are stronger with low pKas

same for bases
low pkb = strong base

opposite for Ka and Kb
- high Ka/Kb is stronger!!