Respuesta :
Answer:
Here's what I get Â
Explanation:
Solubility rules
- Salts containing halides are generally soluble. Important exceptions to this rule are halides of silver, mercury, and lead(II).
- All acetates, chlorates, and perchlorates are soluble
So, PbClâ is insoluble, and Pb(ClOâ)â is soluble.
1. "Molecular" equation
[tex]\rm Pb(ClO_{3})_{2}(aq) + 2HCl(aq) \longrightarrow \, PbCl_{2}(s) + 2HClO_{3}(aq)[/tex]
2. Ionic equation
Convert the soluble salts to their hydrated ions.
HCl and HClOâ are strong acids. Convert them to their ions.
[tex]\rm Pb^{2+}(aq) + 2ClO_{3}^{-}(aq)+ 2H^{+}(aq) + 2Cl^{-}(aq) \longrightarrow \, PbCl_{2}(s) + 2H^{+}(aq) + 2ClO_{3}^{-}(aq)[/tex]
3. Net ionic equation
Cancel all ions that appear on both sides of the reaction arrow (in boldface).
[tex]\rm {Pb}^{2+}(aq) + \textbf{2ClO}_{3}^{-}(aq)+ \textbf{2H}^{+}(aq) + 2Cl^{-}(aq) \longrightarrow \, PbCl_{2}(s) + \textbf{2H}^{+}(aq) + \textbf{2ClO}_{3}^{-}(aq)[/tex]
The net ionic equation is
[tex]\rm {Pb}^{2+}(aq) + 2Cl^{-}(aq) \longrightarrow \, PbCl_{2}(s)[/tex]
4. Theoretical yield
We have the volumes and concentrations of two reactants, so this is a limiting reactant problem. Â
We know that we will need a balanced equation with masses, moles, and molar masses of the compounds involved. Â
(i). Gather all the information in one place with molar masses above the formulas and masses below them. Â
M_r: Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 278.11
            Pb(ClOâ)â + 2HCl â¶ PbClâ + 2HClOâ
Volume/mL: Â Â Â 125 Â Â Â Â Â Â 95
c/mol·Lâ»Âč:      0.85     0.85
(ii) Calculate the moles of each reactant Â
[tex]\text{Moles of Pb(ClO$_{3}$)}_{2} = \text{0.125 L} \times \dfrac{\text{0.85 mol}}{\text{1 L }} = \text{0.1062 mol}\\\text{Moles of HCl} = \text{0.095 L} \times \dfrac{\text{0.85 mol}}{\text{1 L }} = \text{0.08075 mol}[/tex]
(iii) Identify the limiting reactant Â
Calculate the moles of PbClâ we can obtain from each reactant. Â
From Pb(ClOâ)â:
The molar ratio of PbClâ:Pb(ClOâ)â is 2:2
Moles of PbClâ = 0.1062 Ă 2/2 =0.1062 mol PbClâ
From HCl :
The molar ratio of PbClâ:HCl is 1 mol PbClâ:2 mol HCl.
Moles of PbClâ = 0.08075 Ă 1/2 = 0.04038 mol PbClâ
The limiting reactant is HCl because it gives the smaller amount of PbClâ.
(iv) Calculate the theoretical yield of PbClâ.
[tex]\text{Theor. yield of PbCl}_{2} = \text{0.0438 mol} \times \dfrac{\text{278.11 g}}{\text{ 1 mol}} = \textbf{11.2 g}[/tex]
5. Calculate the actual yield of PbClâ
[tex]\text{Actual yield} = \text{11.2 g theor.} \times \dfrac{\text{ 68 g actual}}{\text{100 g theor,}} = \textbf{7.6 g}[/tex]
6. Calculate [ClOââ»]
Original concentration of Pb(ClOâ)â = 0.85 mol·Lâ»Âč
Original concentration of ClOâ = 2 Ă 0.85  = 1.70 mol·Lâ»Âč
The solution was diluted by the addition of HCl.
Total volume = 125 + 95 =220 mL
              câVâ = câVâ
1.70 mol·Lâ»Âč Ă 125 mL = câ Ă 220 mL
      212.5 mol·Lâ»Âč = 200 câ
 câ = (212.5 mL)/200 =  1.06 mol·Lâ»Âč
7. Calculate [PbÂČâș].
Moles of PbÂČâș originally present = 0.1062 mol
        Moles of PbÂČâșremoved = 0.04038 mol
      Moles of PbÂČâș remaining = 0.0659 mol
c = 0.0659 mol/0.220 L = 0.299 mol·Lâ»Âč