The K sp value for strontium fluoride, SrF 2 , is 7.9×10 –10 at 25ºC. Calculate its solubility in g/L.

The KSP value for strontium fluoride, which is s r f 2, is 7.9 times 10 to the negative 10 at 25 degrees Celsius. Here it says to calculate its solubility in grams per liter. Alright. So work I normally see solubility in terms of molarity, which is moles per liter. So what we're gonna have to do here is determine what our molarity is for the compound and then convert it from moles over liters to grams over liters. Strontium fluoride is s r f 2 solid. It breaks them to into our strontium ion plus our 2 fluoride ions. Ksp equals s r 2+timesfminus, the coefficient becomes a power, so that's squared. Here now we can plug in numbers that represent their concentrations. So here this would just be x, and because there's a 2 here, this would be 2 x. So those are the numbers that we plug in for the concentrations. 2 squared is 2 times 2 which is 4, so this is 4 x squared. X times 4x squared is 4x cubed. All right. And they're telling us that the Ksp value is 7.9 times 10 to the negative 10, and that equals the 4x cubed. So just solve for x here. We're gonna divide both sides here by 4. So when I do that, I'm gonna bring it over here, we're gonna see that x x cubed equals 1.975 times 10 to the negative 10. Take the cube root of both sides here. So when I do that, I'm gonna get x equals 5.826 22 5.8236 times 10 to the negative 4 molar. But what exactly does that mean? Well, that means I have 5.8236 times 10 to the negative 4 moles per liter. Because remember molarity is moles per liter. I want the grams per liter. So we're gonna place here on the bottom 1 mole of strontium fluoride and up here the molar mass of strontium fluoride. It's composed of 1 strontium and 2 fluorines. Look on the periodic table and you'll see their masses. Fluorine is 19 grams, strontium is about 87.62 grams. When you combine the masses, you should get the total weight of strontium fluoride as 125.62. Moles cancel out and guess what? I'll have grams per liter at the end. So when I do that, I'm gonna get 7.3 times 10 to the negative 2 grams per liter of strontium fluoride compound. So that would be our final answer for this question.

Table of contents

Skip topic navigation

1. The Chemical World9m
- The Scientific Method
  9m
2. Measurement and Problem Solving2h 19m
3. Matter and Energy2h 15m
4. Atoms and Elements2h 33m
5. Molecules and Compounds1h 50m
6. Chemical Composition1h 23m
7. Chemical Reactions1h 43m
8. Quantities in Chemical Reactions1h 8m
9. Electrons in Atoms and the Periodic Table2h 32m
10. Chemical Bonding2h 10m
11 Gases2h 7m
12. Liquids, Solids, and Intermolecular Forces1h 11m
13. Solutions3h 1m
14. Acids and Bases2h 14m
15. Chemical Equilibrium1h 27m
16. Oxidation and Reduction1h 33m
17. Radioactivity and Nuclear Chemistry53m

15. Chemical Equilibrium

Solubility Product Constant (Ksp)

Introduction to Chemistry

15. Chemical Equilibrium

Solubility Product Constant (Ksp)

Previous problemNext problem

Struggling with Introduction to Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

The K_sp value for strontium fluoride, SrF₂, is 7.9×10^–10 at 25ºC. Calculate its solubility in g/L.

5.8×10^–4 g/L

7.3x10^-2 g/L

4.6×10^–6 g/L

0.092 g/L

Previous problemNext problem

Verified step by step guidance

Understand the dissolution process of SrF2 in water: SrF2(s) ⇌ Sr²⁺(aq) + 2F⁻(aq). This equation shows that one mole of SrF2 produces one mole of Sr²⁺ ions and two moles of F⁻ ions.

Define the solubility of SrF2 as 's' mol/L. At equilibrium, the concentration of Sr²⁺ will be 's' mol/L and the concentration of F⁻ will be '2s' mol/L.

Write the expression for the solubility product constant (Ksp) for SrF2: Ksp = [Sr²⁺][F⁻]². Substitute the concentrations in terms of 's': Ksp = (s)(2s)² = 4s³.

Set the Ksp expression equal to the given Ksp value: 4s³ = 7.9×10⁻¹⁰. Solve for 's' to find the molar solubility of SrF2.

Convert the molar solubility 's' (in mol/L) to solubility in g/L by multiplying by the molar mass of SrF2. The molar mass of SrF2 is approximately 125.62 g/mol.