Still Confused?

Try reviewing these fundamentals first

- Home
- Chemistry 12
- Solubility Equilibrium

Still Confused?

Try reviewing these fundamentals first

Nope, got it.

That's the last lesson

Start now and get better math marks!

Get Started NowStart now and get better math marks!

Get Started NowStart now and get better math marks!

Get Started NowStart now and get better math marks!

Get Started Now- Intro Lesson: a4:19
- Intro Lesson: b2:58
- Intro Lesson: c2:59

In this lesson, we will learn:

- To recall the solubility product expression, K
_{sp}. - How to express solubility and saturation using equilibrium expressions.

- In Solubility and ion concentration, we ‘updated’ our definitions of solubility and saturation. Their correct definitions are about an equilibrium between the dissolved and undissolved state. This means
__we can write solubility as an equilibrium constant expression__.- For example, a saturated solution of the salt MgCl
_{2}, can be described by the equilibrium equation:MgCl _{2 (s)}$\enspace \rightleftharpoons \enspace$ Mg^{2+}_{(aq)}+ 2 Cl^{-}_{(aq)} - The
*solubility product*expression for this equilibrium is:K _{sp}= [Mg^{2+}][Cl^{-}]^{2} - The
*solubility product constant*, K_{sp}, is used for any equilibrium constant between dissolved ions and the undissolved compound; it is the K_{eq}for saturated solutions.

- For example, a saturated solution of the salt MgCl
- Remember how K
_{a}is an “acid strength rating” and K_{eq}is basically a “product rating” in any equilibrium? K_{sp}is effectively a “dissolved ions rating”! A large K_{sp}value means the concentration of dissolved ions in the saturated solution is large.__Therefore the larger the K__._{sp}value, the more soluble a substance is - It’s important to remember the concept of the solubility product constant when dealing with practical problems involving multiple saturated solutions:
- The reason it is called the solubility product CONSTANT is because
__when the solution is saturated, K__, regardless of how the solution was prepared or the relative concentrations. The K_{sp}will be equal to the PRODUCT OF the concentration of dissolved ions_{sp}for any given compound at saturation does not change. Recall that:K _{sp}= [Mg^{2+}][Cl^{-}]^{2}

If MgCl_{2}was dissolved in solution until saturation occurred, we would have a stoichiometric ratio of Mg^{2+}and Cl^{-}ions, according to the equation:MgCl _{2 (s)}$\enspace \rightleftharpoons \enspace$ Mg^{2+}_{(aq)}+ 2Cl^{-}_{(aq)} - However, we could make the saturated solution of magnesium chloride another way, for example two separate compounds may be added in different quantities, such as Mg(NO
_{3})_{2}and NaCl, or other compounds, or varying quantities.

The K_{sp}constant value could be reached if one ion concentration was larger while the other smaller.__Regardless of the proportional ion concentrations, at saturation K__and is the product of the separate dissolved ion concentrations multiplied together._{sp}is constant

- The reason it is called the solubility product CONSTANT is because

- Introduction
__What is the solubility product?__a)K_{sp}and the solubility product expression.b)What does K_{sp}tell us about solubility?c)Expressing solubility and saturation using equilibrium.