# Question 17.14: Calculating the pH at the Equivalence Point in the Titration...

Calculating the pH at the Equivalence Point in the Titration of a Weak Acid by a Strong Base

Calculate the $\mathrm{pH}$ of the solution at the equivalence point when $25 \mathrm{~mL}$ of $0.10 \mathrm{M}$ nicotinic acid is titrated by $0.10 \mathrm{M}$ sodium hydroxide. $K_{a}$ for nicotinic acid equals $1.4 \times 10^{-5}$.

PROBLEM STRATEGY

At the equivalence point, equal molar amounts of nicotinic acid and sodium hydroxide react to give a solution of sodium nicotinate. You first calculate the con- centration of nicotinate ion (stoichiometry problem). Then you find the $\mathrm{pH}$ of this solution (hydrolysis problem).

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Question: 17.9

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STEP 1 Starting concentrations are \left[\m...
Question: 17.8

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Sodium nicotinate gives \mathrm{Na}^{+}[/la...
Question: 17.5

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Morphine, which we abbreviate as Mor, ionizes by p...
Question: 17.4

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CALCULATION of pH Abbreviate the formula for ascor...
Question: 17.2

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STEP 1 At the start (before ionization), the conce...
Question: 17.7

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a. The conjugate acid of \mathrm{CN}^{-}[/l...
Question: 17.13

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Because the reactants are a strong acid and a stro...
Question: 17.12

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When hydronium ion (from hydrochloric acid) is add...
Question: 17.11

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How many moles of $\mathrm{NH}_{3}$ a...
STEP 1 Consider the equilibrium \mathrm{HC}...