https://www.reddit.com/r/askscience/comments/c0mq4s/why_does_increasing_salinity_decrease_specific/
created by JFitG on 14/06/2019 at 17:20 UTC
1 upvotes, 1 top-level comments (showing 1)
I have found numerous sources, but unfortunately most are from things like reddit.
Comment by ummwhoo at 15/06/2019 at 15:31 UTC
3 upvotes, 1 direct replies
The short answer is that at an equilibrium state, water molecules pop off and catch on/attach to the crystal lattice (ice) at the same rate so there is no net change. However, introducing salt molecules and dissolving them into the system makes it harder (read: probabilistically less likely) for the water molecules to attach to the lattice (since they must now compete with the salt molecules), lowering the rate for water molecules attaching to the crystal lattice. Simultaneously, the rate for water molecules leaving/detaching from the lattice remains the same, but now the equilibrium is disturbed, and we know the rate of water molecules attaching is lower, so now there is a net change, which in this case is water molecules leaving the lattice. This is what makes the ice "melt" when salt is added.
Sources:
1.
https://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-melts-ice.shtml
2. Mathews, Holde, Appling and Anthony Cahill's "Biochemistry, 4th Edt." pg. 37-38 (this is more for clathrate cages and dissolving of substances)
3. Any good physical chemistry textbook. I'm personally a fan of Levine. The section on "Solubility" or "Freezing point Depression" will explain it.
Hope this helps.