Question

Write the balanced equation for the reaction of aqueous Pb(CIO), with aqueous Nal. Include phases. chemical equation: Pb(Cl),(aq) + 2 Nal(aq) - PbI,(s) + 2 NaClO3(aq) What mass of precipitate will form if 1.50 L of highly concentrated Pb(CIO), is mixed with 0.550 L 0.120 M Nal? Assume the reaction goes to completion. mass of precipitate: 15.21

Answer 1

The balanced chemical equation for reaction of Pb(ClO₃)₂ with NaI is given by

Pb(ClO₃)₂ (aq) + 2 NaI (aq) $\rightarrow$ PbI₂ (s) + 2NaClO₃ (aq)

To find the mass of precipitate forms, first find moles of reactant

Moles of NaI = Molarity * Volume in Litre = 0.120 mol/L * 0.550 L = 0.066 mol NaI

Mol to mol ratio for NaI to PbI₂ is 2:1.

2 mol NaI = 1 mol PbI₂

0.066 mol NaI = 0.066 mol NaI * (1 mol PbI₂/2 mol NaI) = 0.033 mol PbI₂

Convert this moles to grams by multiplying it by molar mass

0.033 mol PbI₂ * (461.01 g PbI₂/1 mol PbI₂) = 15.2133 g PbI₂

Therefore mass of precipitate form i.e. PbI₂ will be 15.2 g or 15.21 g.