The fundamental difference is that solubility represents a limit on how much solute can dissolve, while a concentrated solution describes a solution where a relatively large amount of solute is already dissolved, potentially approaching or reaching that limit.
Here's a breakdown of the key distinctions:
| Feature | Solubility | Concentrated Solution |
|---|---|---|
| Definition | The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature and pressure. | A solution containing a large amount of solute relative to the amount of solvent. |
| Nature | A property or limit of a substance in a solvent. | A description of the state of a specific solution. |
| Reference Point | The maximum possible concentration under specific conditions. | Refers to the actual amount of solute present in the solution compared to a dilute solution. |
| Related Term (from reference) | "typically a limit to how much solute can dissolve" | Describes a state characterized by a high concentration, which is "the quantitative amount of solute dissolved". |
Let's delve deeper into each term.
Understanding Solubility
Solubility is a specific physical property of a substance (the solute) when mixed with another substance (the solvent). It quantifies the maximum amount of solute that can dissolve in a given quantity of solvent under particular conditions (like temperature and pressure).
- As stated in the reference, solubility is "typically a limit to how much solute can dissolve in a given amount of solvent."
Think of it as the maximum capacity of the solvent to hold the solute. Once this limit is reached, adding more solute will result in the excess solute remaining undissolved (it might settle at the bottom). A solution that has reached its solubility limit is called a saturated solution.
Examples of Solubility:
- Salt (sodium chloride) has a solubility in water. At 20°C, about 360 grams of salt can dissolve in 1 liter of water. You cannot dissolve significantly more than this amount.
- Sugar also has a solubility in water, which increases significantly with temperature.
Understanding a Concentrated Solution
A concentrated solution, on the other hand, is simply a qualitative description of a solution that contains a relatively large amount of solute compared to the amount of solvent. It's the opposite of a dilute solution, which has a relatively small amount of solute.
- While the reference specifically defines concentration as "the quantitative amount of solute dissolved at any concentration in a solvent", a concentrated solution is one characterized by a high value of this quantitative amount.
A solution can be concentrated without necessarily being saturated (at its solubility limit). It just needs to have a significant amount of solute dissolved.
Examples of Concentrated Solutions:
- Highly sweetened tea is a concentrated sugar solution compared to lightly sweetened tea.
- Concentrated orange juice from the supermarket is much more concentrated (contains more orange solids) than ready-to-drink orange juice.
- Strong hydrochloric acid solution is a concentrated solution of HCl in water.
The Relationship
A concentrated solution has a high concentration. The maximum possible concentration a solution can have before it becomes saturated is determined by the solute's solubility in that solvent under those conditions. So, a saturated solution is by definition a concentrated solution (unless the substance has very low solubility), but a concentrated solution is not necessarily saturated.
In essence, solubility is the potential or limit for dissolution, while a concentrated solution describes the actual state of having a high amount of dissolved solute.
