Solubility question

  • Thread starter PPonte
  • Start date
  • #1
PPonte
Why does the solubility of KNO3, in water, rises with increasing temperature and the solubility of Na2SO4 descreases? :approve:
Thank you. :wink:
 

Answers and Replies

  • #2
Gokul43201
Staff Emeritus
Science Advisor
Gold Member
7,082
20
What are your thoughts ?

We can't help you unless you help yourself. :biggrin:
 
  • #3
PPonte
I am sorry. I usually help people who do not present their thoughts, I never remeber those rules.

Here are my thoughts:
1. The dissolution of a salt involves two phases. First, the separation of the ions, which is endoenergetic because involves breaking of ionic bonds and, second, the solvatation, in this case, an hydration since the solvent is water, which is exoenergetic.

2. If the energy consumed in the first phase is greater than the energy freed in the second phase, the dissolution of the salt is globally endoenergetic. If the energy consumed in the first phase is minor than the energy freed in the second phase, the dissolution of the salt is globally exoenergetic.

Conclusion: I think, then, that the dissolution of KNO3 is globally endoenergetic, so rises with increasing temperature, and the dissolution of Na2SO4 is globally exoenergetic so decreases with increasing temperature.

Am I right?
 
  • #4
Gokul43201
Staff Emeritus
Science Advisor
Gold Member
7,082
20
Perfectly.

PS : Please do not help folks that show no original effort. It is rarely helpful to the student in the long run.
 

Related Threads on Solubility question

  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
6
Views
9K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
9
Views
6K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
3
Views
9K
  • Last Post
Replies
4
Views
803
  • Last Post
Replies
5
Views
4K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
5
Views
4K
Top