To remove lead from a contaminated water solution, a chemist decides to precipitate it out by adding sodium chloride to the solution. From 108.7 g of the solution with a density of 1.03 g/mL, the chemist recovers 0.152 g of PbCl2. What is the concentration of Pb2+in the original solution in molarity?

The concentration of Pb²⁺ in the original solution in molarity is 0.00518 M/L

Explanation:

Given;

mass of the solution = 108.7g

density of the solution = 1.03 g/mL

Volume of solution = mass of the solution/density of the solution

Volume of solution = 108.7/1.03 = 105.53 mL

Number of mole of PbCl₂ = Reacting mass/molar mass

molar mass of PbCl₂  = (207.2 + 71) = 278.2 g/mol

Number of mole of PbCl₂ = (0.152/278.2) = 0.000546 M

PbCl₂ ⇄ Pb²⁺ + 2Cl⁻

1          :    1      :  2

1 mole of PbCl₂ = 1 mole of Pb²⁺

0.000546 mole of PbCl₂ = 0.000546 mole of Pb²⁺

Molarity of Pb²⁺ = (number of moles of Pb²⁺)/(Liters of solution)

Molarity of Pb²⁺ = (0.000546 mole)/(105.33 X 10⁻³L)

Molarity of Pb²⁺ = 0.00518 M/L

Therefore, the concentration of Pb²⁺ in the original solution in molarity is 0.00518 M/L

personal, she chose to do it.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.