To minimize the effect of buret reading errors, titrations...

To minimize the effect of buret reading errors, titrations performed using a $50-\mathrm{mL}$ buret are most accurate when titrant volumes are in the range of 35 to $45 \mathrm{~mL}$. Suggest a range of sample weights that would yield a 35 - to 45 -mL titration range for the standardization of solutions of the following approximate concentrations. (a) $0.0533 \mathrm{M} \mathrm{NaOH}$ using potassium hydrogen phthalate $\left(\mathrm{C}_{8} \mathrm{H}_{5} \mathrm{KO}_{4}\right)$, a monoprotic acid. (b) $0.0895 M$ KOH using primary standard benzoic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right)$, a monoprotic acid.

To minimize the effect of buret reading errors, titrations performed using a $50-\mathrm{mL}$ buret are most accurate when titrant volumes are in the range of 35 to $45 \mathrm{~mL}$. Suggest a range of sample weights that would yield a 35 - to 45 -mL titration range for the standardization of solutions of the following approximate concentrations.
(a) $0.0533 \mathrm{M} \mathrm{NaOH}$
using potassium hydrogen phthalate $\left(\mathrm{C}_{8} \mathrm{H}_{5} \mathrm{KO}_{4}\right)$, a monoprotic acid. (b) $0.0895 M$ KOH using primary standard benzoic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right)$, a monoprotic acid.

Key Concepts

Acid-Base Titration

Acid-base titration is an analytical technique used to determine the concentration of an analyte by reacting it with a titrant of known concentration. This process involves carefully adding the titrant to the analyte until the reaction reaches an endpoint, which is usually indicated by a color change or pH change. It relies on the stoichiometric relationship between the reactants as described by a balanced chemical equation.

Buret Reading Accuracy

Buret reading accuracy is crucial in titrations because it directly impacts the precision of the volume measurement of the titrant delivered. Operating within an optimal volume range helps minimize reading errors, which can come from parallax or meniscus misinterpretation. By selecting a titrant volume range that maximizes accuracy, experimental errors are reduced, leading to more reliable results.

Standardization Using Primary Standards

Standardization is the process of determining the exact concentration of a titrant by reacting it with a primary standard. A primary standard is a substance of known high purity, stability, and reactivity, making it ideal for accurately calibrating solutions. Using a primary standard ensures that subsequent titration measurements are based on well-defined reagent concentrations.

Stoichiometric Calculations

Stoichiometric calculations involve using a balanced chemical equation to relate the amounts (in moles) of the reactants and products. In a titration, this allows for the determination of the unknown concentration of an analyte by measuring the volume of titrant required to reach the endpoint, and then applying the mole-to-mole relationships defined by the reaction.

Mole-to-Mass Conversion

Mole-to-mass conversion is a critical concept in titration calculations as it involves converting the number of moles of a substance, determined from stoichiometric calculations, into grams using its molar mass. This conversion is essential when selecting an appropriate sample weight that will yield a measurable and accurate titration volume within the optimal range for buret reading.

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