1. Lab 4 Notes Solutions

2. are homogeneous mixtures of two or more substances consist of a solvent (larger amount, usually a liquid) and solutes (smaller amount, usually a solid) solutes are uniformly dispersed within the solvent

3. Concentration of Solution - Molarity Molarity M = moles/liter 1 M = 1 mole/L 1 mole of NaCl has the mass of Na: 22.99 g/mole + Cl: 35.45 g/mole NaCl: 58.44 g/mole How to make a solution of 1M NaCl: Mass out 58.44 g then dissolve in 1 L water

4. Concentration of Solutions - % % (m/v) is another frequently used concentration measure mass of solute__ x 100% volume of solution

5. Types of Solution

6. Water is the most common solvent. is a polar molecule. forms hydrogen bonds with solutes

7. Diffusion Passive movement of substances from an area of high concentration to an area of low concentration

8. Osmosis Diffusion of water across a semipermeable membrane Water flows form from an area of lower solute concentration (hypotonic) to area of higher solute concentration (hypertonic), assume the solute cannot move Isotonic: both areas have the same concentration Semipermeable small molecules can go through, large molecules cannot

9. Dialysis Filtration of solutions through a selectively permeable membrane. dialysis membranes let water and certain solutes (those that have the right size) move across the membrane to equalize Example: membranes of kidney let water, waste molecules, salt and sugar move across (sugar is reabsorbed!), but blood cells are too big