For an explanation, see the main splats page
The principles of solutions
- Some substances dissolve other substances: solids may dissolve in a liquid, and solutions may also be formed of gas in liquid, or even liquid in liquid.
- When a solution is formed, the solute is divided up by mixing with the solvent until it is in the form of individual molecules or ions, depending on what it is.
- Solution concentrations can be measured either in terms of a mass per unit volume, as moles per litre, or as parts per million or billion, depending on need.
- The maximum concentration of a solution can be predicted from basic information about the attractive forces involved in the solute and solvent.
- Solubility relies on differences in attraction between the particles being dissolved on the one hand, and between the particles and the solvent on the other.
- A colloid is not quite a solution, but it is not really a mixture either, given the size and even spread of the suspended particles that make up the colloid.
- In 1848, Karl von Vierordt established that the osmotic pressure of a solution is always proportional to the concentration of solute in that solution.
- Osmotic pressure refers to the force with which a concentrated solution draws water from a weaker one, or pure solvent, through a semi-permeable membrane.
- Osmosis involves the flow of solvent from a less concentrated solution to a more concentrated one, through a semi-permeable membrane. The solute cannot pass.
- An isotonic solution is one that has the same osmotic pressure as tissue placed in it, designed so that the cells of the tissue remain correctly hydrated.
- Ringer's solution is an example of a standard isotonic solution. It is used to maintain tissues in a living state for experimental purposes and histology.
- The observation of osmosis in action offers us clear evidence that atoms exist, since there is no other explanation for the effects that are seen and measured.
- A polysaccharide is an example of a polymer: a variety of polysaccharides are used in living things to store carbohydrates without making hypertonic solutions.
This file is http://members.ozemail.com.au/~macinnis/scifun/, first created on February 17, 2009. Last recorded revision (well I get lazy and forget sometimes!) was on February 17, 2009.
©The author of this work is Peter Macinnis, who asserts his sole right to the product as it is packaged here, recognising that many of the ideas are common. You are free to use this as a model to do your own version. Copies of this whole file or site may be made and stored or printed for personal or educational use. You can contact me at email@example.com, but only if you add my first name to the front of that email address -- this is a low-tech way of making it harder to harvest the e-mail address I actually read.
This site had 219,000 hits on the index page from 1999 to January 2007 and an unknown number on other pages. In January 2007, a combined counter was placed on all of the pages, counting page hits which now total