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Labs 8-15
Various definitions
| Term | Definition |
|---|---|
| Colloid | A homogenous mixture that does not separate or settle out. The particles will pass through a filter but not a semi-permeable membrane. |
| Solution | A homogenous mixture of two or more substances |
| Semipermeable membrane | allows solvent molecules such as water and very small solute particles to pass through. |
| Suspensions | Contain very large size solute particles. These particles can be seen without a microscope making it heterogeneous. |
| Osmosis | Passage of solvent through a semipermeable membrane. |
| Dialysis | Passage of small particles as well as water through a semipermeable membrane. |
| KSCN | Used to test the presence of FeCl3. Red is a positive result. |
| Iodine | Used to test for the presence of starch. A blue-black color is a positive result. |
| Tyndall Effect | The ability of light to shine through a solution. Readings can be from strong to dim light. It shows how dense the particles are in the suspension. |
| Acid | A substance that ionizes and produces H+ ion when dissolved in water. |
| Base | A substance that produces OH- when dissolved in water or an H+ acceptor. |
| Ammonia shown as a base | A water molecule has to be included as a reactant. |
| Buffer | A solution that will resist changes in pH when small amounts of acid or base are added. |
| Buffer systems | Comprised of a weak base and the salt of a weak base. |
| Example of weak acetic acid | HC2H3O2 (acetate) --> acetic acid |
| Three common buffers that regulate the human body | carbonate system, phosphate system and the protein system |
| Blue | base |
| Red | acid |
| Solute concentration | Amount of solute dissolved in a certain amount of solvent or solution. |
| Molarity | Number of moles of solute per liter of solution and is given the symbol M. |
| Molar mass |