Does any solid PbCl2 form when 3.1 mg NaCl is dissolved in 0.228 L of 0.12 M Pb(NO3)2.
Find the Qsp.
To find the solubility product constant, Qsp, we need to determine if any solid PbCl2 will form when 3.1 mg NaCl is dissolved in 0.228 L of 0.12 M Pb(NO3)2.
The balanced chemical equation for the reaction between Pb(NO3)2 and NaCl is:
Pb(NO3)2 + 2NaCl → PbCl2 + 2NaNO3
The molar mass of NaCl is 58.44 g/mol, and the molar mass of PbCl2 is 278.1 g/mol.
First, we need to find the number of moles of NaCl in 3.1 mg:
Mass of NaCl = 3.1 mg = 0.0031 g
Number of moles of NaCl = mass / molar mass
= 0.0031 g / 58.44 g/mol
Next, we need to find the number of moles of Pb(NO3)2 using the molarity and volume given:
Number of moles of Pb(NO3)2 = Molarity × Volume
= 0.12 mol/L × 0.228 L
Since the balanced chemical equation has a stoichiometry ratio of 1:2 between Pb(NO3)2 and NaCl, we need to double the number of moles of Pb(NO3)2 before comparing it to the number of moles of NaCl.
Now, we can compare the number of moles of Pb(NO3)2 with NaCl. If the number of moles of Pb(NO3)2 is greater than twice the number of moles of NaCl, then there will be no solid PbCl2 formed.
Finally, we can calculate the solubility product constant (Qsp):
Qsp = [Pb2+][Cl-]^2
If the concentrations of Pb2+ and Cl- ions are known, substitute those values into the equation to calculate Qsp.
To summarize, follow these steps to find the solubility product constant (Qsp):
1. Calculate the number of moles of NaCl using the given mass and molar mass.
2. Calculate the number of moles of Pb(NO3)2 using the given molarity and volume.
3. Double the number of moles of Pb(NO3)2.
4. Compare the number of moles of Pb(NO3)2 with twice the number of moles of NaCl.
5. If the number of moles of Pb(NO3)2 is greater, no solid PbCl2 will form.
6. If a solid PbCl2 does form, calculate Qsp using the concentrations of Pb2+ and Cl- ions.
PbCl2 ==> Pb^2+ + 2Cl^-
Ksp = )Pb^2+)(Cl^-)^2
NaCl ==> Na^+ + Cl^-
Convert 3.1 mg NaCl to moles and M NaCl = mole/L soln where L soln = 0.228.
Then Qsp = (Pb^2+)(Cl^-)^2
Substitute (Pb^2+) from Pb(NO3)2. Substitute (Cl^-) from NaCl M from above.
If Qsp > Ksp, a ppt will occur.
If Qsp < Ksp, a ppt will not occur.