SolutionProperties.ppsx
- 2. CA Standards Students know the definitions of solute and solvent. Students know how to describe the dissolving process at the molecular level by using the concept of random molecular motion. Students know temperature, pressure, and surface area affect the dissolving process.
- 4. Solute A solute is the dissolved substance in a solution. A solvent is the dissolving medium in a solution. Solvent Salt in salt water Sugar in soda drinks Carbon dioxide in soda drinks Water in salt water Water in soda
- 5. “Like Dissolves Like” Fats Benzene Steroids Hexane Waxes Toluene Polar and ionic solutes dissolve best in polar solvents Nonpolar solutes dissolve best in nonpolar solvents Inorganic Salts Water Sugars Small alcohols Acetic acid
- 6. Water’s Solvent Interactions The oxygen (slightly negative) end of the water molecule is attracted to the positive ion of a salt.
- 7. Water’s Solvent Interactions The hydrogen (slightly positive) end of the water molecule is attracted to the negative ion of a salt.
- 8. Solubility Trends The solubility of MOST solids increases with temperature. The rate at which solids dissolve increases with increasing surface area of the solid. The solubility of gases decreases with increases in temperature. The solubility of gases increases with the pressure above the solution.
- 9. Therefore… Solids tend to dissolve best when: o Heated o Stirred o Ground into small particles Gases tend to dissolve best when: o The solution is cold o Pressure is high
- 10. Solubility Chart
- 11. An electrolyte is: A substance whose aqueous solution conducts an electric current. A nonelectrolyte is: A substance whose aqueous solution does not conduct an electric current. Definition of Electrolytes and Nonelectrolytes
- 12. The ammeter measures the flow of electrons (current) through the circuit. If the ammeter measures a current, and the bulb glows, then the solution conducts. If the ammeter fails to measure a current, and the bulb does not glow, the solution is non-conducting. Electrolytes vs. Nonelectrolytes
- 13. 1.Pure water 2.Tap water 3.Sugar solution 4.Sodium chloride solution 5.Hydrochloric acid solution 6.Lactic acid solution 7.Ethyl alcohol solution 8.Pure sodium chloride Try to classify the following substances as electrolytes or nonelectrolytes…
- 14. ELECTROLYTES: NONELECTROLYTES: Tap water (weak) NaCl solution HCl solution Lactate solution (weak) Pure water Sugar solution Ethanol solution Pure NaCl Answers to Electrolytes
- 15. Colligative Properties Colligative properties are those that depend on the concentration of particles in a solution, not upon the identity of those particles. Boiling Point Elevation Freezing Point Depression Osmotic Pressure
- 16. Freezing Point Depression Each mole of solute particles lowers the freezing point of 1 kilogram of water by 1.86 degrees Celsius. Each mole of nonvolatile solute particles raises the boiling point of 1 kilogram of water by 0.51 degrees Celsius. Boiling Point Elevation