Determine the concentrations of mgcl2, mg2 , and cl– in a solution prepared by dissolving 2.75 × 10–4 g mgcl2 in 1.75 l of water. express all three concentrations in molarity. additionally, express the concentrations of the ionic species in parts per million (ppm).

M of MgCl₂ = 1.65 × 10⁻⁶ M

M of Mg²⁺ = 1.65 × 10⁻⁶ M

M of Cl⁻ = 3.30 × 10⁻⁶ M

Explanation:

1) MgCl₂

Molarity = number of moles of solute / volume of solution in liters, M = n / V

n = mass in grams / molar mass

molar mass of MgCl₂ = 24.305 g/mol + 2(35.543 g/mol) = 95.211 g/mol

n = 2.75 × 10⁻⁴ g / 95.211 g/mol = 2.89×10⁻³ moles

⇒ M = n / V = 2.89×10⁻³ moles / 1.75 l = 1.65 × 10⁻⁶ M

2) Mg²⁺ and Cl⁻

Those are the ions in solution.

You assume 100% dissociation of the ionic compound (strong electrolyte).

Then the equation is: MgCl₂ → Mg²⁺ + 2Cl⁻

That means that 1 mol of MgCl₂ produces 1 mol of Mg²⁺ and 2 moles of Cl⁻.

That yields the same molarity concentration of Mg²⁺ , while the molarity concentration of Cl⁻ is the double.

So, the results are:

M of MgCl₂ = 1.65 × 10⁻⁶ M

M of Mg²⁺ = 1.65 × 10⁻⁶ M

M of Cl⁻ = 3.30 × 10⁻⁶ M

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.

6.4 cm (max) - 25 cm (min)