Lead ion can be precipitated from solution with NaCl according to the reaction: Pb2 (aq)+2NaCl(aq) PbCl2(s)+ 2Na (aq) When 135.8 g of NaCI are added to a solution containing 195.7g of Pb2*, a PbCl2 precipitate forms. The precipice is filtered and dried ad found to have a mass of 252.4g. Determine the limiting reactant, theoretical yield of PbC12, and percent yield for the reaction

Respuesta :

Answer:

[tex]Pb^{2+}[/tex] is limiting reagent.

Theoretical yield = 262.67 g

% yield = (Experimental yield / Theoretical yield) × 100 = (252.4 / 262.67) × 100 = 96.1 %

Explanation:

The formula for the calculation of moles is shown below:

[tex]moles = \frac{Mass\ taken}{Molar\ mass}[/tex]

Given: For [tex]NaCl[/tex]

Given mass = 135.8 g

Molar mass of [tex]NaCl[/tex] = 58.44 g/mol

Moles of [tex]NaCl[/tex] = 135.8 g / 58.44 g/mol = 2.3238 moles

Given: For [tex]Pb^{2+}[/tex]

Given mass = 195.7 g

Molar mass of [tex]Pb^{2+}[/tex] = 207.2 g/mol

Moles of [tex]Pb^{2+}[/tex] = 195.7 g / 207.2 g/mol = 0.9445 moles

According to the given reaction:

[tex]Pb^{2+}_{(aq)}+2NaCl_{(aq)}\rightarrow PbCl_2_{(s)}+2Na^+_{(aq)}[/tex]

1 mole of [tex]Pb^{2+}[/tex] react with 2 moles of [tex]NaCl[/tex]

Also,

0.9445 mole of [tex]Pb^{2+}[/tex] react with 2*0.9445 moles of [tex]NaCl[/tex]

Moles of [tex]NaCl[/tex] = 1.889 moles

Available moles of [tex]NaCl[/tex] = 2.3238 moles  (Extra)

Limiting reagent is the one which is present in small amount. Thus, [tex]Pb^{2+}[/tex] is limiting reagent.

The formation of the product is governed by the limiting reagent. So,

1 mole of [tex]Pb^{2+}[/tex] gives 1 mole of [tex]PbCl_2[/tex]

0.9445 mole of [tex]Pb^{2+}[/tex] gives 0.9445 mole of [tex]PbCl_2[/tex]

Mole of [tex]PbCl_2[/tex]  = 0.9445 moles

Molar mass of [tex]PbCl_2[/tex] = 278.1 g/mol

Mass of [tex]PbCl_2[/tex] = Moles × Molar mass = 0.9445 × 278.1 g = 262.67 g

Theoretical yield = 262.67 g

Given experimental yield = 252.4 g

% yield = (Experimental yield / Theoretical yield) × 100 = (252.4 / 262.67) × 100 = 96.1 %

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