What is the difference between Qsp and Ksp? | Socratic
Consider the reaction the reaction MX(s) M+(aq) + X-(aq) Qsp is the solubility priduct of the concentration of ions in solution of a dissolving ionic solid. An introduction to basic solubility product calculations. What is the difference between Ksp and Qsp? Ksp is the solubility product constant whereas Qsp is the solubility product quotient. The solubility.
Solubility and complex ion formation Video transcript - [Voiceover] There are many ionic compounds that are only slightly soluble in water. And lead two chloride is one of those ionic compounds. So let's say that we added 10 grams of lead two chloride to 50 milliliters of water at a temperature of 25 degrees Celsius.
And let's say that only. All right, so most of the lead two chloride is undissolved and we can go ahead and show that in our beaker over here. So let's say that this represents our undissolved lead two chloride, right? So this is a solid in our beaker. Some of the lead two chloride does dissolve, a small amount.
We're going to have lead two plus ions in solution, PB two plus and chloride anions, Cl minus. So this is just a little bit of a picture of what's happening, right?
Solubility and Equilibrium
We now have a saturated solution of lead two chloride. We have a saturated solution. So we have ions in solution and we have a large amount of undissolved lead two chlorides. All right, in part A, our job is to calculate the solubility of lead two chloride in water at 25 degrees Celsius.
And first, we're going to find the solubility in grams per liter. All right, so in grams per liter. If we move our decimal place one, two, three that's. So that is the solubility. And the solubility is the number of grams of solute in one liter of a saturated solution.
So if you had one liter of water, you could only dissolve about 4. So this is why this is only a slightly soluble ionic compound. A small amount dissolves. All right, we could also find the solubility in moles per liter, which would be the molar solubility. So we know grams, we know the grams is. To find moles, we need to know the molar mass.
So for lead two chloride we have lead with a molar mass of So we have To that we'd have to add two times So two times If we add that to That's the molar mass of PbCl2. So if we divide the grams by the grams per mole, we divide grams by We'd get one over one over moles.
So this would tell us how many moles.
So let's get out the calculator and let's do this. So if I round that, we would get. We're trying to find the molar solubility, so we need to divide moles by liters. And we already saw the liters was. We'll go ahead and use the rounded number here.
So this is equal to. Moles over liters is molarity. So this is the molar solubility of lead two chloride in water at 25 degrees Celsius. You have to make sure to specify the temperature because, obviously, if you change the temperature, you change how much can dissolve in the water. All right, so that's the idea of solubility and molar solubility. In part B our goal is to calculate the solubility product constant, Ksp, at 25 degrees Celsius for lead two chloride. Ksp is really just an equilibrium constant.
So let's think about a solubility equilibrium. Let's think about this picture right up here.
So we have a saturated solution of lead two chloride and our solution is in contact with our solid, lead two chloride, here. And at equilibrium the rate of dissolution is equal to the rate of precipitation. Ksp of a BaSO4 Saturated Solution When one of these ions are added from an external source, then the above equilibrium shifts towards the left-hand side a more insoluble form of the substance is formed decreasing the amount of ions present in the solutiondecreasing the solubility of that substance.
Qsp is the solubility product quotient of a solution. It describes the current state of a solution. This means Qsp is given for an unsaturated before saturationsaturated or a supersaturated solution.
Solubility Product Application Prediction Precipitation Qualitative Analysis
The Qsp is also called the ion product because it is the product of concentrations of ionic species at any moment not at a specific moment such as saturation. Therefore, Ksp the solubility product constant is a special form of Qsp.
What is the Relationship Between Ksp and Qsp? If the Qsp value is less than the Ksp for a substance in a solution, more solids can be dissolved in that solution.
When the Qsp and Ksp have equal values, then the solution has become saturated. If the Qsp is higher than the value of Ksp, a precipitate is formed. What is the Difference Between Ksp and Qsp? Ksp vs Qsp Ksp is the solubility product constant of a particular substance. Nature Ksp is an equilibrium value. Qsp is not an equilibrium value. State of the Solution Ksp is the product of concentrations of ionic species in a saturated solution.
Qsp is the product of concentrations of ionic species in an unsaturated, saturated or a supersaturated solution.Ksp v Qsp
Ksp is defined as a saturated solution which has equilibrium between ionic species and a solid precipitate the moment at which the formation of a precipitate has begun. Qsp is given for any moment not specified ; before the saturation or after the saturation.