When a liquid is able to completely dissolve in another liquid the two liquids are miscible
Two substances that can never mix to form a solution are called immiscible.
A solution reached the maximum solubility is called a saturated solution. Often, another phase such as gas, liquid, or solid of the solute is present and in contact with in the solution. In general, there is no net change in the amount of solute dissolved, but the system is by no means static. In fact, the solute is constantly being dissolved and deposited at equal rate. Such a phenomenon is called equilibrium.
In case another phase is not present, a solution may be unsaturated or supersaturated. Yes, due to what can be attributed to a kinetic factor, a solution may stay supersaturated for a long time. When promoted by a seed, a solution may start to precipitate quickly. Sodium acetate has a very high solubility at say 270 K. In fact, it can dissolve in the water of crystallization similar to melting. When cooled, such a solution stay in a meta-stable state. When a seeding crystal is present or started due to surface of another medium, the entire solution will solidify. During the crystallization process, heat is evolved, and the solution becomes warm. Thus, such a solution, when properly packaged, has been used as hand warmer packs for skiers.
One useful classification of materials is polarity. Substances such as H2, O2, N2, CH4, CCl4 etc are called non-polar compounds, whereas H2O, NH3, CH3OH, NO, CO, HCl, H2S, PH3 etc are called polar compounds. Regarding solubility, a useful rule is
Like dissolves like.
Polar materials dissolve polar materials whereas non-polar materials will mix and become true solutions. An additional factor to consider is the hydrogen bonding. For example, ethanol and water are completely miscible at any proportion due to the extensive hydrogen bonding among their molecules.
Electrolytes or ionic substances are soluble in water due to hydration. Due to the strong polarity of the water molecule, the positive and negative ions are pushed apart. In general, reasonable size ions are believed to have six water molecules around them, but these water molecules readily exchange with those in the medium.
There are many applications of this rule. On the small scale, personal hygiene and household cleaning requires various types of cleaning agents. As a challenge is the research and development of cleaning agents in industry, where you can find jobs or hire experts to do the R&D.
Other factor such as temperature and pressure also affects the solubility of a solvent. Thus, in specifying solubility, one should be aware of the factors.
I. Assignment
In your kitchen, try to dissolve the following substances in water. Record whether they are insoluble or soluble. Arrange your data in a table.
1. Salt2. Sugar
3. Baking soda
4. Baking Powder
5. Vinegar
6. Vanilla Extract
7. Vegetable Oil
8. Dish washing liquid
9. Vaseline
10. Hand Lotion.
1.
Please… Kindly tell III Mercury about this websites because I forgot to tell them. Write your answer in your notebook and prepare for a pre-test. See you on Friday
