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What are acids and bases according to Arrhenius' definition?
Acids produce H⁺ (or H₃O⁺) in water; bases produce OH⁻ in water
Define acids and bases using Bronsted-Lowry theory.
Acids are proton donors; bases are proton acceptors
What is a Lewis acid and a Lewis base?
A Lewis acid accepts an electron pair; a Lewis base donates an electron pai
What is the autoionization constant of water (Kw) at 25°C?
Kw=[H+][OH−]=1.0×10^−14.
How is pH calculated?
pH=−log[H+].
What is the relationship between pH and pOH?
pH+pOH=14 at 25°C
What is the pH of a neutral solution at 25°C?
pH = 7, where [H+]=[OH−]=1.0×10^−7 M.
What characterizes strong acids and bases?
They completely ionize in water
Give an example of a weak acid and its dissociation constant (Ka
Acetic acid, Ka=1.75×10^−5.
What is the relationship between Ka, Kb, and Kw?
Ka×Kb=Kw
What is the Henderson-Hasselbalch equation for pH?
pH=pKa+log([A⁻][HA]).
When does pH equal pKa?
When the concentrations of the acid and its conjugate base are equal
What is a buffer?
A solution that resists changes in pH when small amounts of acid or base are added
Give an example of a buffer system.
Acetic acid and sodium acetate
How is buffer capacity defined?
The ability of a buffer to resist changes in pH
What is the equivalence point in an acid-base titration?
The point at which the amount of acid equals the amount of base added
How does the pH change at the equivalence point of a strong acid-strong base titration?
It is approximately 7.0
What indicator is suitable for weak acid-strong base titrations?
Phenolphthalein (pH range 8.3–10.0)
Why do polyprotic acids have multiple equivalence points?
They can donate more than one proton
Why are non-aqueous titrations used?
For weak acids or bases that do not show sharp endpoints in water
Name a solvent and titrant used for weak acids in non-aqueous titrations.
Solvent: Dimethylformamide; Titrant: Tetrabutylammonium hydroxide
Name a solvent and titrant used for weak bases in non-aqueous titrations.
Solvent: Glacial acetic acid; Titrant: Perchloric acid
How is pH calculated for a 0.0001 M HCl solution?
pH = -log(0.0001) = 4.0
What is the pH of a 0.1 M sodium acetate solution?
pH=8.9 (calculated using Kb and Henderson-Hasselbalch equation)
How do acid-base indicators work?
They change color over a specific pH range depending on ionization
Give an example of an indicator for strong acid-strong base titrations.
Methyl red (pH range 4.4–6.2)
Why is phenolphthalein unsuitable for strong acid-strong base titrations?
Its color change occurs beyond the equivalence point
What is the relationship between pH and hydrogen ion concentration?
[H+]=10^−pH
How is pOH calculated?
pOH=−log[OH−]
What is the effect of diluting a buffer solution?
It reduces buffer capacity but does not significantly change pH
