Unit 9 - Acids and Bases - Honors Flashcards
Definition of Amphoteric (3)
- Compound that acts as both a base & acid
- Can donate & accept a proton
- Depends if they’re reacting w/ acid or base
Water (H₂O):
Acts as a base: When reacting with a strong acid like HCl, it accepts a proton, forming H₃O⁺.
Acts as an acid: When reacting with a strong base like NH₃, it donates a proton, forming OH⁻.
Hydrogen carbonate (HCO₃⁻):
Acts as a base: When reacting w/ acid HCl, it accepts a proton, forming H₂CO₃ (carbonic acid)
Acts as an acid: When reacting with a base like NaOH, it donates a proton, forming CO₃²⁻ (carbonate ion)
Definition of Lewis Acid (2)
- Accepts e- pair to form coordinate covalent bond
- Typically contain incomplete octets/orbitals (e- deficient)
- Electrophilic (e- loving)
Definition of Lewis Base (3)
- Donates e- pair to form coordinate covalent bond
- Contains lone pair/unbonded pair of e-
- Nucleophilic (nucleus loving)
Definition of Conjugate Acid (4)
- Protonated Product
- Received dissociated proton from parent acid
- Parent Base gains H+ from Parent Acid
- Becomes Conjugate Acid
(H+ is Attatched)
Definition of Conjugate Base (4)
1.Negatively Charged Product
2.Remains after p+ dissociated from parent acid
3. Parent acid loses its H⁺ to Parent base
4. Becomes a conjugate base
(H+ is Lost)
How can you determine the strength of an acid when finding conjugates?
Stronger Acids (Dissociates More) = Weak Conjugate Base (Less likely to grab H+)
Weaker Acids (Dissociates Less) = Strong Conjugate Base (More likely to grab H+)
Strong acids, like HCl, dissociate completely bc weak H⁺ bonds are readily broken due to electronegative atoms like Cl pulling electrons away, resulting in stable, unreactive conjugate bases like Cl⁻ that remain as nonreactive spectator ions in solution.
- Strong Acids have Weak Bond of H⁺ & molecule
- Weak bonds make it easier for the acid to dissociate & release the H⁺
- HCl bond is weak
- Cl is very electronegative & holds onto shared e- tightly
- This pulls them away from H
- Making it an bond easier to break
- bc H⁺ is even more “ready” to leave
- When a strong acid loses H⁺
- Conjugate base is highly unreactive, discouraging dissociation
- Cl⁻ doesn’t tend to grab H+ & revert back to HCl b
- HCl completely dissociates in water, leaves Cl⁻ as a non-reactive spectator ion
Definition of Ka (3)
- Dissociation Constants for Acids
- Determines the Strength of Acid
- How well something dissociates until they reach equilibrium
Definition of Kb (3)
- Dissociation Constants for Bases
- Determines the Strength of Bases
- How well something dissociates until they reach equilibrium
What is the formula for Ka? (4)
- Same formula as Keq
- Products/Reactants, Convert Coefficients to Exponents
- Conjugate Acid x Conjugate Base/Parent Acid
- Water is NEVER included
- High Ka = Dissociates well, Strong Acid
- Low Ka = Dissociates poorly, Weak Acid
What is the formula for Kb? (4)
- Same formula as Keq
- Products/Reactants, Convert Coefficients to Exponents
- Conjugate Acid x Conjugate Base/Parent Base
- Water is NEVER included
Definition of ICE Tables
Use ICE Tables for this problem
1. 3x3 Table
2. Column - Initial, Change, Equilibrium
3. Row - Parent, H+, Parent - H+
4. I: Initial Conc. (before the reaction starts)
5. C: Change in Conc. (what’s lost/gained during dissociation)
6. E: Equilibrium Conc. (What’s left after rxn balances)
Ex: [H+] of 0.10M solution of HCNO is 0.0010M (Calculate Ka for HCNO)
1. HCNO = H⁺ + CNO⁻
2. HCNO is Acid, H+ is Proton, CNO is Base
3. HCNO is INITIALLY 0.10M, and H+ and CNO- is 0
4. Subtract H+ Conc. from HCNO Conc. & add to H+ & CNO-
5. 0.0010 M of HCNO dissociates, ending in a loss of 0.0010M of HCNO
6. HCNO at Equilibrium = 0.099
7. H+ at Equilibrium = 0.001
8. CNO- at Equilibrium = 0.001
9. Plug in Values to Ka Equation (Remember, Coefficients = Exponents)
Rank Strongest to Weakest Acids (10)
- HI
- HBr
- HCl
- HNO3 (Nitric Acid)
- H2SO4 (Sulfuric Acid)
- HClO4 (Perchloric Acid)
- HClO3 (Chloric Acid)
- HF
- HCOOH
- CH3COOH
Rank Strongest to Weakest Bases
- Ba(OH)2 (Barium hydroxide)
- Sr(OH)2 (Strontium hydroxide)
- KOH (Potassium hydroxide)
- NaOH (Sodium hydroxide)
- LiOH (Lithium hydroxide)
- Ca(OH)2 (Calcium hydroxide)
- Mg(OH)2 (Magnesium hydroxide)
- CH3NH2 (Methylamine)
- NH3 (Ammonia)
- NH4OH (Ammonium hydroxide)
What’s a Net Ionic Equation?
- Predict Products of Rxn (Double Replacement of Anions & Cations)
- Balance Ionic Equation
- Dissociate Ions (aq) to Cations & Anions (Insoluble Compounds (s) CANNOT Dissociate)
- Add Charges & Phases - (aq) for dissociated Ions and (s) for insoluble compounds
- Cross Out Spectator Ions that Dissociated & didn’t change charge/phase
- NEVER CROSS OUT SOLID INSOLUBLE COMPOUNDS IN REACTANT
How do Acids & Bases apply to Net Ionic Equations?
Weak Acids & Bases (HF, HCOOH, CH3COOH, NH3, NH4, OH, CH3, NH2)
What should you do when given the pH instead of the H+ concentration?
H+ = 10⁻ᵖʰ
