Which of the following situations is most favorable for solubility?
For an ionic solid to dissolve into a liquid, the ions must dissociate and become surrounded by solvent molecules. An example of a water-soluble ionic solid is table salt, NaCl. Salt-water can be written as NaCl(aq) indicating "aqueous." see the figure.
In contrast, an example of a water-insoluble ionic substance is zinc sulfide. Zinc sulfide does not dissociate in water, and therefore the ions cannot become hydrated. Its formula is written ZnS(s) where the s stands for "solid." See the figure.
Ionic compounds are not the only substances that can dissolve in liquids. Molecular compounds can also dissolve if the individual molecules can become solvated.
Based on the information from the introduction, you can now understand the concept of electrolytes. An electrolye is any compound that can form ions when dissolved in water and therefore conduct electricity. Strong acids, strong bases, and soluble salts fit this category. NaCl is an electrolyte because it is a soluble salt and therefore dissociates. ZnS is not an electrolyte, because it is an insoluble salt and therefore does not dissociate. Sugar, even though it is soluble, is not an electrolyte because it does not dissociate into ions.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Electrolytes concept. You can view video lessons to learn Electrolytes. Or if you need more Electrolytes practice, you can also practice Electrolytes practice problems.