Calculating Molar Solubility of Lithium Phosphate

If Ksp Lithium Phosphate is 3.2x10⁻⁹. What is the molar solubility of Lithium Phosphate?

Transcript

00:00If Ksp lithium phosphate is 3.2 times 10 to the power of negative 9, what is the molar

00:08solubility of lithium phosphate?

00:12Okay, the first step is identification.

00:19The solubility product constant of lithium phosphate is 3.2 times 10 to the power of

00:24negative 9.

00:27The next step is to analyze the ion equilibrium.

00:33In water, a lithium phosphate molecule ionizes into 3 lithium ions and 1 phosphate ion.

00:42Lithium phosphate molecules and their ions form a chemical equilibrium.

00:47So the number of ions in the solution is the same.

00:56Assume that there are S moles of phosphate ions in the solution, and the molarity of

01:04phosphate ions is S molar, and the volume of the solution is 1 liter.

01:14So the molarity of lithium ions is 3 S molar, and the molarity of phosphate ions is S molar.

01:24The third step is to write the chemical equilibrium equation.

01:28It is not easy to read this equilibrium reaction.

01:32Just look at what is displayed on the screen.

01:37Now we can calculate the value of S from Ksp.

01:41Ksp is equal to the concentration of lithium ions to the power of 3, times the concentration

01:47of phosphate ions.

01:50Entering the values of ion concentration and Ksp, 27 S to the power of 4 is equal to

01:563.2 times 10 to the power of negative 9.

02:01We can write this equation as S to the power of 4.

02:06If I'm not mistaken, S is about 3.3 times 10 to the power of negative 3 molar.

02:14The fifth step is to calculate the molar solubility value.

02:18Based on the ionization equation, S moles of phosphate ions in a 1 liter solution are

02:23produced by S moles of lithium phosphate molecules.

02:33So the molar solubility of lithium phosphate is S, or 3.3 times 10 to the power of negative

02:393 moles per liter.

02:43Yup, hopefully this tutorial can provide an overview of how to calculate molar solubility

02:48from Ksp.

02:53And don't forget to follow this channel.