1. Effect of Temperature
For some substances to dissolve in a given solvent, heat is absorbed. The reaction is endothermic. In this case, an increase in temperature increases solubility. For some substances, heat is released when they dissolve in a given solvent. The reaction is called exothermic. In this case, an increase in temperature decreases solubility. Generally, an increase in temperature in the solubility of solids in liquids increases solubility. But for solubility of gas in liquids, an increase in temperature decreases solubility because gas evaporates as temperature increases. . 2. Effect of Pressure
Pressure unlike temperature has little effect on solutions unless the solute is a gas. An increase in pressure causes greater interaction between particles of the gas and the liquid, thus, increasing solubility. 3. Nature of solute and solvent
Nature of both the solute and the solvent affect the solubility. •Substances with similar intermolecular attractive forces tend to be soluble in one another. This generalization is stated as "like dissolves like." •Non polar solutes are soluble in non polar solvents; Polar or ionic solutes are soluble in polar solvents •
Liquids that are attracted by charged objects are composed of polar molecules; those that are not attracted by a charged body are non polar Rate of Solubility
Sharon Barfield Perkins Bass
1140 W. 66th St.
Chicago IL 60621
This can be adapted for any grade. Discover factors affecting the rate of solution.
The materials are for each group of four.
1. Test tube with cork 9. Sugar cubes
2. Two clear plastic cups 10. Aspirin
3. Pestle 11. Salt tablets
4. Mortar 12. Mint candy
5. Clock with second hand or stopwatches 13. Water
6. Alcohol burner 14. Alka Seltzer
7. Goggles 15. Junior Mints
8. Mints 16. Tongs
1. Introduce and discuss solvent, soluble, solute, insoluble, and rate. 2....