To determine the pCI and pAg values after the titration, we need to consider the reaction between AgNO3 and HCl, as well as the solubility product constant (Ksp) of AgCl.
The balanced chemical equation for the reaction between AgNO3 and HCl is:
AgNO3 + HCl -> AgCl + HNO3
From the equation, we can see that one mole of AgNO3 reacts with one mole of HCl to form one mole of AgCl.
Given:
Volume of AgNO3 solution (VAgNO3) = 20 mL
Molarity of AgNO3 solution (MAgNO3) = 0.1 M
Volume of HCl solution (VHCl) = 6 mL
Molarity of HCl solution (MHCl) = 0.2 M
pKsp(AgCl) = 9.8
Step 1: Determine the number of moles of AgNO3 and HCl used in the reaction.
Moles of AgNO3 = MAgNO3 * VAgNO3
Moles of AgNO3 = 0.1 M * 20 mL / 1000 mL/L
Moles of HCl = MHCl * VHCl
Moles of HCl = 0.2 M * 6 mL / 1000 mL/L
Step 2: Determine the limiting reactant.
The limiting reactant is the one that is completely consumed in the reaction. Since AgNO3 and HCl react in a 1:1 mole ratio, the limiting reactant is the one with fewer moles.
Step 3: Calculate the moles of AgCl formed.
Since AgNO3 and HCl react in a 1:1 mole ratio, the moles of AgCl formed will be equal to the moles of the limiting reactant.
Step 4: Calculate the concentration of Ag+ ions in the solution.
The concentration of Ag+ ions will be equal to the moles of AgCl formed divided by the total volume of the solution.
Step 5: Calculate pAg and pCI.
pAg = -log10[Ag+]
pCI = -log10[CI-]
Since the chloride ions (CI-) come from HCl and are in excess, the concentration of CI- will be equal to the initial concentration of HCl.
Comparing the given answer choices:
A). pAg = pCI = 4.9
B). pAg = 8.29 and pCI = 1.5
C). pAg = 9.8 and pCI is undetermined.
D). None of the above.
Based on the calculations, we can see that the correct answer is:
C) pAg = 9.8 and pCI is undetermined.
The pAg value is determined by the concentration of Ag+ ions, which depends on the formation of AgCl. However, the pCI value cannot be determined without additional information about the dissociation of HCl in water.
Learn more about HCl