Hello!

 

I have a little question about the solubility of calcium hydroxide.. Does the solubility decrease or increase when the temperture is raised?

 

Your help will be very much appreciated! Thank you!

Solubility of solids and liquids in water increases with temperature solubility of gasses in water decreases with increased temperature.

 

The answer is the solubility of calcium hydroxide increases with increased temperature.

Solubility of solids and liquids in water increases with temperature solubility of gasses in water decreases with increased temperature.

 

The answer is the solubility of calcium hydroxide increases with increased temperature.

Really? cerium(III) sulfate decreases it's solubility with temperature, sodium sulfate also starts to become less soluble after ~30C.

 

But I think that calcium hydroxide get's more soluble when heated.

Solubility of solids and liquids in water increases with temperature solubility of gasses in water decreases with increased temperature.

 

This is an oversimplification. What is [math]\Delta[/math]H in this case?

Why would you want to know the enthalpy change ([math]\Delta{H}[/math])? It just says how much heat develops (whether it cools or heats) when you dissolve the [ce]Ca(OH)2[/ce].

 

I don't recommend trying to derive this from thermodynamic formula's. Either look it up, or measure it.

 

The easy way is to search in a Handbook, such as Perry's Chemical Engineers' Handbook. Since you probably don't have that book, and I do, I looked it up for you.

 

Solubility of the anhydrous Ca(OH)2 (but anhydrous is the standard form - it does not have any crystal water)

 

0 deg C - 0.185 g / 100 g water

10 deg C - 0.176 g / 100 g water

20 deg C - 0.165 g / 100 g water

30 deg C - 0.153 g / 100 g water

40 deg C - 0.141 g / 100 g water

50 deg C - 0.128 g / 100 g water

60 deg C - 0.116 g / 100 g water

70 deg C - 0.106 g / 100 g water

80 deg C - 0.094 g / 100 g water

90 deg C - 0.085 g / 100 g water

100 deg C - 0.077 g / 100 g water

 

If you use this data, please include the reference: "Perry, Green, Perry's Chemical Engineers' Handbook, 7th Edition, McGraw-Hill, 1998, New York" because that's where I found this. Disclaimer, I might have gotten the official order of the reference wrong (I never know what comes first: publishers, or year or so).

Hello!

 

I have a little question about the solubility of calcium hydroxide.. Does the solubility decrease or increase when the temperture is raised?

 

Your help will be very much appreciated! Thank you!

 

The solubility should decrease with increased temperature