If the theoritical yield of PbCl2 is 16.547 g from the reaction of 7.000 g of NaCl with 50.400 g of Pb(NO3)2. Calculate the % yield of PbCl2 if 12.798 g of PbCl2 was actually obtained? (Atomic mass: Na-22.990 g/mol; 0-15.999 g/mol; Cl-35.453g/mol; Pb-207.200 g/mol; N-14.007).

100%

77.343%

38.343%

60.551%

1 answer

The first step is to determine the theoretical yield of PbCl2 using stoichiometry. The balanced chemical equation for the reaction is:

2 NaCl + Pb(NO3)2 -> 2 NaNO3 + PbCl2

From the equation, we can see that 2 moles of NaCl react with 1 mole of Pb(NO3)2, producing 1 mole of PbCl2. The molar masses of the relevant compounds are:

NaCl: 22.990 + 35.453 = 58.443 g/mol
Pb(NO3)2: 207.200 + 2(14.007 + 3(15.999)) = 331.200 g/mol
PbCl2: 207.200 + 2(35.453) = 278.106 g/mol

Using the masses given, we can calculate the moles of each reactant:

NaCl: 7.000 g / 58.443 g/mol = 0.1197 mol
Pb(NO3)2: 50.400 g / 331.200 g/mol = 0.1520 mol

Since 2 moles of NaCl react with 1 mole of Pb(NO3)2, the limiting reactant is NaCl. Therefore, the moles of PbCl2 produced is:

0.1197 mol NaCl x (1 mol PbCl2/2 mol NaCl) = 0.0598 mol PbCl2

Finally, we can calculate the theoretical yield of PbCl2:

0.0598 mol PbCl2 x 278.106 g/mol = 16.618 g PbCl2

The percent yield is then calculated by dividing the actual yield by the theoretical yield and multiplying by 100%:

percent yield = (12.798 g / 16.618 g) x 100% = 77.343%

Therefore, the answer is 77.343%.