# How can a saturated solution decrease in solubility?

Watch
Announcements
#1
On the Snaprevise website, it is explained that in the crystallisation process, 'cooling the saturated solution leads to a decrease in solubility, meaning more crystals are formed from the solution.'

This confuses me, because if a solution is saturated, then no more solute can be dissolved in it. I am confused what the website means by the saturated solution becoming more insoluble.
0
1 year ago
#2
Solubility changes with temperature. On cooling, there is a decrease in solubility, so less solute is dissolved in solution. The solute precipitates out
0
1 year ago
#3
It's the solute that becomes less soluble.
0
#4
(Original post by EierVonSatan)
It's the solute that becomes less soluble.
I'm confused as to how that works? Because isn't the solute not soluble anymore due to the solution being saturated anyway?
0
1 year ago
#5
(Original post by luckypie)
I'm confused as to how that works? Because isn't the solute not soluble anymore due to the solution being saturated anyway?
Solubility is how much solute can be dissolved in a given mass of solvent.

If you try to add more solute to a saturated solution of that solute, it won't dissolve. That dosen't mean that the solute is insoluble just that it can't dissolve any more into that solution.

Does this make sense?
1
1 year ago
#6
(Original post by luckypie)
I'm confused as to how that works? Because isn't the solute not soluble anymore due to the solution being saturated anyway?
"The solute is not soluble anymore" - this is not true. The saturated solution contains the maximum amount of solute that can dissolve in it at that temperature. It still has solute. But at the higher temperature, the solution carried more solute. When cooled, the solubility of the solute in the solvent fell, so less solute was in the solution. The solute which crashed out of solution is seen as crystals.

Solubility of a solute in a particular solvent is defined as the mass of the solute dissolved per unit mass of that solvent. The solubility varies with temperature. A saturated solution is one which contains the maximum amount of solute. e.g If I have 100g of water and a substance X has a solubility of 4g/100g water, then I can only dissolve 4g of X in it and no more. The solution then formed is called a saturated solution.
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Are you tempted to change your firm university choice on A-level results day?

Yes, I'll try and go to a uni higher up the league tables (9)
37.5%
Yes, there is a uni that I prefer and I'll fit in better (2)
8.33%
No I am happy with my choice (13)
54.17%
I'm using Clearing when I have my exam results (0)
0%