[777888]

1a)Describe an experimental design(briefly) you could use to determine the solubility of Ca(OH)2 in water at 60^oC
-I don't know how to do this question.

2)Why in electrochemisty, when we see H+ and OH- in a chemical reaction, we always (e.g. when balancing redox equations) combine them to form H2O?

Thanks for helping!

[777888]

Also, I have some questions about "Chemical Systems in Equilibrium":

3)I don't get what is the diference between Dynamic Equilibrium and Solubility Equilibrium.

4)Why does stirring help to dissolve a solute?

Thank you!

[Mitch]

4) Helps disperse the solute to other parts of the solution that doesn't have it in it. It's basically helping the entropy along.

[777888]

Why in electrochemisty, when we see H+ and OH- in a chemical reaction, we always (e.g. when balancing redox equations) combine them to form H2O?

Anyone know this?

Thanks

[Mitch]

Just part of the rules, I'm not sure if it has a chemical significance.

[Donaldson Tan]

redox reactions that involves aqueous medium would use H⁺ and OH^- to balance the charges. These ions are always present with water, why not use them to aid the electron transfer process?

dynamic equilibrium is achieved in a chemical system whereby the forward reaction rate equals the backward reaction rate, such that the composition of the system remains unchanged [steady].

solubility equilibrium refers to a specific type of dynamic of equilibrium whereby a substance dissolves in a solvent, eg. water.

figuring out solubility of calcium hydroxide at 60^oC
1. dissolve excess calcium hydroxide at 60^oC
2. filter the undissolved calcium hydroxide away.
3. heat the solution to 80degrees
4. titrate with appropriate indicator.

(3) is used because solubility increases with temperature. it helps to prevent re-precipitation of calcium hydroxide

[777888]

Thanks for your help