Answer :
Density relates the mass of a compound to its volume. We will first find the mass of the solution using the density and volume given. We have the following equation:
[tex]\rho=\text{ density = }\frac{Mass}{Volume}[/tex]We clear the mass,
[tex]\begin{gathered} Mass\text{ = }\rho\times Volume \\ Mass\text{ =}4.65\frac{g}{mL}\times3000mL \\ Mass\text{ =}13950\text{ g} \end{gathered}[/tex]So, the mass of paint is 13950 g. Now the mass percentage of the lead in the paint will be calculated as follows:
[tex]\begin{gathered} \%mass=\frac{\text{ Mass of lead (II) nitride}}{Mass\text{ of paint}}\times100 \\ \%mass=\frac{33.1\text{ g}}{13950\text{ g}}\times100 \\ \%mass=0.24\% \end{gathered}[/tex]The mass percentage of lead in the paint is 0.24%.
ppm concentration means the quantity of solute in milligrams (mg) is in a liter (L) of a solution. So, to calculate ppm concentration we will divide the milligrams of lead (II) nitride between the liters of paint:
[tex]\begin{gathered} \text{ppm = }\frac{\text{33.1g of lead}\times\frac{1000mg}{1g}}{3L} \\ \text{ppm =11033ppm of lead} \end{gathered}[/tex]The ppm of lead in the paint is 11033ppm.
