Lessons in any basic subject up to the high school level. -Starting with Math and Chemistry, but I can help in anything else... probably xD
Spanish notes incoming
- "Solubility refers to the maximum amount of solute that will dissolve in a given amount of solvent at a specified temperature and pressure. As a substance is being solvated, eventually a point will be reached where the particle of solute will begin to collide and reform the crystal. At this point, the solute is said to be in equilibrium, or saturated."
What this is essentially saying is that solubility is measured in terms of the maximum amount of solute that will dissolve in a solvent, and when the maximum amount of solute is dissolved in a solvent, the solution is saturated.
Oops! This image does not follow our content guidelines. To continue publishing, please remove it or upload a different image.
This image helps you understand what they mean by a "saturated solution". Take a look at KClO₃ at 70°C. (Find 70°C on the x-axis and then move up the y-axis until you find KClO₃).
What mass of KClO₃ will dissolve in 100 mL of water? (Note: 100 mL = 100 g)
If you follow the line with which KClO₃ intersects, you will notice that 30 g of KClO₃ at 70°C will dissolve in 100 mL of water. This is a saturated solution. In other words, if the point is on the line, the solution is saturated.
- Okay, so now what do I call these substances?
Depending on whether or not a substance dissolves in a solvent, it is either soluble or insoluble. Usually, whentwo liquids are mixed together, they are described as miscible or immiscible.
Soluble/miscible means the solute will dissolve in the solvent.
Insoluble/immiscible means the substance(s) will not dissolve.
- Cool... but that means some substances cannot be in a saturated solution... so what are they?
Well, first of all, it's important to know what is in a saturated solution.
"In a saturated solution, the solvent contains the maximum amount of solute."
Oops! This image does not follow our content guidelines. To continue publishing, please remove it or upload a different image.
• There are two other types of solutions.
unsaturated and supersaturated
"In an unsaturated solution, the solvent contains less than the maximum amount of solute."
Oops! This image does not follow our content guidelines. To continue publishing, please remove it or upload a different image.
"In a supersaturated solution, the solvent contains more than the maximum amount of solute. A supersaturated solution is very unstable and the amount in excess can precipitate or crystallize."
Oops! This image does not follow our content guidelines. To continue publishing, please remove it or upload a different image.
- So how do I make these solutions saturated?
"Any solution can be made saturated, unsaturated, or supersaturated by changing the temperature."
Oops! This image does not follow our content guidelines. To continue publishing, please remove it or upload a different image.
Important Notes:
"When looking at solubility curves* of different compounds:
• Least soluble = lowest line at a given temperature
• Most soluble = highest line at a given temperature
• For solids - As temperature increases, solubility of a solid solute will increase
• For gasses - As temperature increases, solubility of a gas will decrease (line goes down)"
*refer to the first graph
So, really, solubility curves just help us compare different solutions' solubility.
If I were to ask you:
Which is the most soluble at 90°C?
A. KClO₃
B. NaCl
C. K₂Cr₂O₇
D. KCl
You would find 90°C on the x-axis, and go all the way up the y-axis (taking note of the points of each of the substances), and see which of these four solutions was the most soluble.
In this case, the most soluble solution would be C. K₂Cr₂O₇ because its point on the line at 90°C is higher than the points of the other three.
Feel free to ask any questions.
Works Cited
1. Allan, Andy. Solubility Curves Graph. Digital image. ScienceGeek.Net. N.p., n.d. Web. 07 Mar. 2017.
