Concentration vs. Strength : Concentration vs. Strength Concentrated vs. Dilute Strong vs. Weak
Slide 2 : H+ A - H+ A - HA
A - H+ A - H+ A –
H+ A - H+ A - H+
A - HA H+ A -
H+ A - H+ A - H+ HA HA HA HA
HA HA HA
H+ A - HA HA
HA HA H + A –
HA H + A – HA HA H+ A- H+ A- H+ A- H+ A- HA
A- H+ A- H+ A- H+ A- H+ A -
H+ A- HA H+ A- H+ A- H+ A-
A- H+ A- H+ A- H+ A- H+ A- H+
H+ A - H + A - H + A - HA H + A -
A- H+ A- H+ A- H+ A- H+ A–
H+ A- H+ A- H+ A- H+ A- H+
A- H+ A- H+ A- H+ A- H+ A-
HA A- H+ A- H+ A- H+ A- H+ HA HA H+ A- HA HA HA
HA HA HA HA HA H+ A-
H+ A- HA HA HA HA HA
HA HA H+ A- HA HA HA
HA HA HA H+ A- HA HA
H+ A- HA HA HA HA HA
HA HA HA H+ A- HA HA
H+ A- HA HA HA HA HA
HA HA H+ A- HA HA HA DILUTE CONCENTRATED STRONG WEAK STRONG ACIDS
Dissociate nearly 100%
HA H1+ + A-
WEAK ACIDS
Dissociate very little
HA H1+ + A- Acids: Concentration vs. Strength
Comparison of Strong and Weak Acids : Comparison of Strong and Weak Acids Type of acid, HA Reversibility
of reaction Ka value Ions existing when acid,
HA, dissociates in H2O Strong Not
reversible Ka value very large H+ and A-, only.
No HA present. Weak reversible Ka is small H+, A-, and HA HA(aq) + H2O(l) H3O+(aq) + A-(aq) The equilibrium expression for the reaction is Ka = [H3O+] [A-] [HA] Note: H3O+ = H+
Strong vs. Weak Acid : Strong vs. Weak Acid Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 508
Concentrated vs. Dilute : Concentrated vs. Dilute 0.3 M HCl 2.0 M HCl 12.0 M HCl 10.0 M CH3COOH Dilute, strong acid Concentrated, strong acid OR Dilute, strong, acid Concentrated, strong acid Concentrated, weak acid
Naming Acids : Naming Acids _________ ide
(chloride, Cl1-) _________ite
(chlorite, ClO2-)
(hypochlorite, ClO-) _________ ate
(chlorate, ClO3-)
(perchlorate, ClO4-) Hydro____ ic acid
(hydrochloric acid, HCl) _________ic acid
(chloric acid, HClO3)
(perchloric acid, HClO4) ______ous acid
(chlorous acid, HClO2)
(hypochlorous acid, HClO) Anion Acid add H+ add H+ add H+ ions ions ions
Slide 7 : Increasing acid Strength Increasing base Strength Increasing acid Strength Increasing base Strength Brown, LeMay, Bursten, Chemistry 2000, page 625
Equilibrium and pH Calculations : [H3O+] Equilibrium and pH Calculations HA + H2O H3O+ + A- Weak acid HA + H2O H3O+ + A- Strong acid acid-dissociation
constant calculations [HA] = [H3O+] + pH 0 7 14 antilog(-pH) -log [H3O+] = [OH-] - Tocci, Viehland, Holt Chemistry Visualizing Matter 1996, page 525