What is the molarity of a solution that contains 45 mEq Ca“ per liter?

0.0225 M

Explanation:

In one liter of this solution, there are 45 mEq of Ca⁺².

1 mEq of Ca⁺² is equal to 20 mg of Ca⁺. We know this by dividing its molar mass (40) by the charge of the ion (2).

Meaning that 45 mEq of Ca⁺² is equal to (45 * 20) 900 mg of Ca⁺².

Now we convert 900 mg of Ca⁺² into moles, using its molar mass:

900 mg / 1000 = 0.9 g0.9 g Ca⁺² ÷ 40 g/mol = 0.0225 mol Ca⁺²

Finally we calculate the molarity of the solution:

Molarity = moles / liters0.0225 mol / 1 L = 0.0225 M

Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.