CHEM 134 C001 — Spring 2026
Digital Laboratory — Beyond Labz Virtual Chemistry
Acid-Base Chemistry
Student Name: Date: Section: Score:
____________________________ _______________ C001 _______
/ 100
LEARNING OBJECTIVES
Upon completing this digital lab, you will be able to:
• Define acids and bases using Arrhenius, Bronsted-Lowry, and Lewis
theories
• Calculate pH and pOH of strong and weak acid/base solutions
• Distinguish between strong and weak acids/bases based on percent
dissociation
• Interpret and construct titration curves for acid-base reactions
• Identify equivalence points and calculate Ka/Kb from experimental data
• Understand buffer systems and calculate buffer capacity using the
Henderson-Hasselbalch equation
• Predict the behavior of acid-base indicators and select appropriate
indicators for titrations
BACKGROUND & THEORY
,1. Definitions of Acids and Bases
Theory Acid Definition Base Definition
Arrhenius Produces H+ ions in Produces OH- ions in
aqueous solution aqueous solution
Bronsted- Proton (H+) donor Proton (H+) acceptor
Lowry
Lewis Electron pair acceptor Electron pair donor
2. pH Scale and Key Equations
The pH scale measures the acidity or basicity of a solution on a scale from 0 to
14:
Equation Formula Notes
pH pH = -log[H+] Lower pH = more
acidic
pOH pOH = -log[OH-] Lower pOH = more
basic
pH + pOH relationship pH + pOH = 14 (at Always true at
25°C) standard conditions
Water autoionization Kw = [H+][OH-] = 1.0 x At 25°C
10^-14
H+ from pH [H+] = 10^(-pH) Antilog of -pH
OH- from pOH [OH-] = 10^(-pOH) Antilog of -pOH
3. Strong vs. Weak Acids and Bases
Property Strong Weak Example
Acid/Base Acid/Base
Dissociation 100% Partial (<< HCl vs.
(complete) 100%) CH3COOH
Equilibrium Reaction goes Equilibrium NaOH vs. NH3
to completion established
, Property Strong Weak Example
Acid/Base Acid/Base
Ka/Kb value Very large (>>1) Small (<<1) Ka(HCl) >>
Ka(HF)
pH calculation Direct from Requires ICE See Part B
concentration table below
Common Strong Acids: HCl, HBr, HI, HNO3, H2SO4 (first ionization), HClO4
Common Strong Bases: NaOH, KOH, LiOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
4. Equilibrium Expressions
For a weak acid HA: HA(aq) + H2O(l) ⇌ H3O+(aq) + A-(aq)
Ka = [H3O+][A-] / [HA]
For a weak base B: B(aq) + H2O(l) ⇌ BH+(aq) + OH-(aq)
Kb = [BH+][OH-] / [B]
Important relationship: Ka x Kb = Kw = 1.0 x 10^-14 (for a conjugate acid-base
pair)
5. Henderson-Hasselbalch Equation (Buffers)
pH = pKa + log([A-] / [HA])
This equation applies to buffer solutions containing a weak acid and its conjugate
base. Buffers resist changes in pH upon addition of small amounts of strong acid
or base.
Buffer capacity is maximized when [A-] = [HA], at which point pH = pKa.
Digital Laboratory — Beyond Labz Virtual Chemistry
Acid-Base Chemistry
Student Name: Date: Section: Score:
____________________________ _______________ C001 _______
/ 100
LEARNING OBJECTIVES
Upon completing this digital lab, you will be able to:
• Define acids and bases using Arrhenius, Bronsted-Lowry, and Lewis
theories
• Calculate pH and pOH of strong and weak acid/base solutions
• Distinguish between strong and weak acids/bases based on percent
dissociation
• Interpret and construct titration curves for acid-base reactions
• Identify equivalence points and calculate Ka/Kb from experimental data
• Understand buffer systems and calculate buffer capacity using the
Henderson-Hasselbalch equation
• Predict the behavior of acid-base indicators and select appropriate
indicators for titrations
BACKGROUND & THEORY
,1. Definitions of Acids and Bases
Theory Acid Definition Base Definition
Arrhenius Produces H+ ions in Produces OH- ions in
aqueous solution aqueous solution
Bronsted- Proton (H+) donor Proton (H+) acceptor
Lowry
Lewis Electron pair acceptor Electron pair donor
2. pH Scale and Key Equations
The pH scale measures the acidity or basicity of a solution on a scale from 0 to
14:
Equation Formula Notes
pH pH = -log[H+] Lower pH = more
acidic
pOH pOH = -log[OH-] Lower pOH = more
basic
pH + pOH relationship pH + pOH = 14 (at Always true at
25°C) standard conditions
Water autoionization Kw = [H+][OH-] = 1.0 x At 25°C
10^-14
H+ from pH [H+] = 10^(-pH) Antilog of -pH
OH- from pOH [OH-] = 10^(-pOH) Antilog of -pOH
3. Strong vs. Weak Acids and Bases
Property Strong Weak Example
Acid/Base Acid/Base
Dissociation 100% Partial (<< HCl vs.
(complete) 100%) CH3COOH
Equilibrium Reaction goes Equilibrium NaOH vs. NH3
to completion established
, Property Strong Weak Example
Acid/Base Acid/Base
Ka/Kb value Very large (>>1) Small (<<1) Ka(HCl) >>
Ka(HF)
pH calculation Direct from Requires ICE See Part B
concentration table below
Common Strong Acids: HCl, HBr, HI, HNO3, H2SO4 (first ionization), HClO4
Common Strong Bases: NaOH, KOH, LiOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
4. Equilibrium Expressions
For a weak acid HA: HA(aq) + H2O(l) ⇌ H3O+(aq) + A-(aq)
Ka = [H3O+][A-] / [HA]
For a weak base B: B(aq) + H2O(l) ⇌ BH+(aq) + OH-(aq)
Kb = [BH+][OH-] / [B]
Important relationship: Ka x Kb = Kw = 1.0 x 10^-14 (for a conjugate acid-base
pair)
5. Henderson-Hasselbalch Equation (Buffers)
pH = pKa + log([A-] / [HA])
This equation applies to buffer solutions containing a weak acid and its conjugate
base. Buffers resist changes in pH upon addition of small amounts of strong acid
or base.
Buffer capacity is maximized when [A-] = [HA], at which point pH = pKa.
