Question

A solution contains 0.133 g of dissolved Lead. How many moles of soduim chloride must be added to the solution to completly precipitate all of the disolved lead?

Answer 1

Hello!

0,00128 moles of Sodium Chloride must be added to the solution to completely precipitate 0,133 g of dissolved Lead.

The chemical reaction for the precipitation of lead from an aqueous solution is:

Pb⁺²(aq) + 2NaCl(aq) → PbCl₂(s) + 2Na⁺(aq)

To calculate how many moles of NaCl are needed, we'll use the following conversion factor to go from grams of Pb⁺² to moles of NaCl using atomic masses and reaction coefficients:


`0,133 g Pb^(+2) * (1 mol Pb^(+2))/(207,2 g Pb^(+2))* (2 mol NaCl)/(1 mol Pb^(+2))=0,00128 moles NaCl`

Have a nice day!