To calculate the molarity of Pb(NO3)2(aq), you need to know the molar mass of the compound. The molar mass of Pb(NO3)2 is 331.21 g/mol.
Using the equation, concentration = moles/liters, we can calculate the molarity of the Pb(NO3)2(aq) solution.
First, we need to calculate the moles of Pb(NO3)2. We can do this by converting the mass of the precipitate (19.40 g) to moles. Moles = mass (g) / molar mass (g/mol).
Therefore, moles of PbCl2 = 19.40 g / 331.21 g/mol = 0.05833 moles.
Next, we can calculate the molarity of Pb(NO3)2. Molarity = moles/liters.
Therefore, the molarity of Pb(NO3)2 = 0.05833 moles/ 0.2 liters = 0.29165 M.