Assume that the electrical conductivity of a solution depends on the total concentration of dissolved ions and that you measure the conductivity of three different solutions while carrying out titration procedures: (a) Begin with 1.00 L of 0.100 M KCl, and titrate by adding 0.100 M AgNO₃. (b) Begin with 1.00 L of 0.100 M HF, and titrate by adding 0.100 M KOH. (c) Begin with 1.00 L of 0.100 M BaCl₂, and titrate by adding 0.100 M Na₂SO₄. Which of the following graphs corresponds to which titration?

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Identify the chemical reactions occurring in each titration: (a) KCl + AgNO_3 \rightarrow AgCl(s) + KNO_3, (b) HF + KOH \rightarrow KF + H_2O, (c) BaCl_2 + Na_2SO_4 \rightarrow BaSO_4(s) + 2NaCl.

Consider the solubility of the products: AgCl and BaSO_4 are insoluble, leading to precipitation, while KF is soluble.

Analyze the change in ion concentration: (a) As AgNO_3 is added, Ag^+ ions react with Cl^- to form AgCl, reducing ion concentration and conductivity. (b) HF is a weak acid, and KOH neutralizes it, increasing ion concentration and conductivity. (c) Ba^2+ ions react with SO_4^2- to form BaSO_4, reducing ion concentration and conductivity.

Predict the conductivity trend: (a) Conductivity decreases as AgCl precipitates. (b) Conductivity initially increases as HF is neutralized. (c) Conductivity decreases as BaSO_4 precipitates.

Match each graph to the titration based on the predicted conductivity trends.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrical Conductivity

Electrical conductivity is a measure of a solution's ability to conduct electric current, which depends on the presence and concentration of ions in the solution. The more ions present, the higher the conductivity, as ions are the charge carriers. In titration, changes in conductivity can indicate the progress of the reaction and the formation of new ions or complexes.

Titration and Reaction Types

Titration is a quantitative analytical technique used to determine the concentration of a solute in a solution by reacting it with a titrant of known concentration. Different types of titrations, such as acid-base or precipitation titrations, involve specific reactions that affect the ion concentration and, consequently, the conductivity of the solution. Understanding the nature of the reactants and products is crucial for predicting conductivity changes.

Ion Formation and Precipitation

During titration, the formation of new ions or precipitates can significantly alter the conductivity of the solution. For example, in the titration of KCl with AgNO3, a precipitate of AgCl forms, reducing the number of free ions in solution. In contrast, the titration of HF with KOH involves the neutralization of an acid and a base, which affects the ion concentration differently, impacting the conductivity readings throughout the titration process.

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(a)

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