1. Objective: To have a basic understanding of solutions Do Now: What condition(s) do you think will dissolve sugar the quickest? a.Increase of temperature b.Sugar cubed instead of granulated c.Leaving it alone in the water

2. Solutions Homogeneous mixtures that may be solid, liquid or gas Solvent- dissolving medium Solute- the dissolved particle Substances that dissolve most readily in water include ionic compounds, and polar covalent compounds (acids/bases)

3. Suspensions and Colloids Suspensions- mixtures from which particles settle out upon standing – Can easily be separated through filtration Colloids- heterogeneous mixture which the particles are smaller than those in suspension, but larger than those in solution Examples of colloids: glue, paint, milk, whipped cream, marshmallows, mayo, fog, dust in air, jelly, blood, jell-o

4. Tyndall Effect The scattering of visible light by colloidal particles Typically you cannot see a beam of sunlight unless it masses through particles of water or dust (as they scatter through them) This distinguishes solutions from colloids and suspensions

5. Solutions Review Homogeneous mixture Will not scatter light Typically the solute will be an ionic compound or a polar covalent compound (HCl, HBr, H 2 CO 3 )

6. Three Factors that Affect Dissolving Agitation: stirring, shaking, swirling all increases the rate of dissolving Temperature: solutes will dissolve quicker in higher temperature Particle Size of the Solute: because smaller particles of solute expose a much greater surface area, it will dissolve quicker – Cube sugar will dissolve slower than granulated

7. Solubility Solubility: the amount of solute that dissolves in given quantity of solvent at a specified temperature and pressure to produce a saturated solution Saturated: solution that contains the maximum amount of solute for a given quantity of solvent at a constant temperature and pressure excess solute will not dissolve once it reaches solubility

8. Solubility Unsaturated: solution that contains less solute at a given temperature and pressure additional solute will dissolve in solvent until it reaches solubility Supersaturated: contains more solute than it can theoretically hold in a given temperature

9. Miscible v. Immiscible Miscible- two liquids can dissolve each other in all proportions – Polar and polar – Nonpolar and nonpolar Immiscible- Liquids that are insoluble in one another Polar and Nonpolar (oil and water) This also determines how soluble a solute will be – Polar or ionic molecule will have high solubility in polar solvents – Nonpolar molecules will have low solubility in polar solvents

10. Which of the following has high solubility in water? Hydrochloric acid (strong acid HCl) Ammonia (weak base NH 3 )) Sugar (C 12 H 22 O 11 ) Copper (II) sulfate (CuSO 4 ) Sodium chloride (NaCl)

11. Electrolytes Electrolytes- compound that conducts an electric current when it is in aqueous solution or molten state – Ionic compounds – Acids/bases Nonelectrolytes- compounds that do NOT conduct electric currents – Carbon based compounds – Molecular compounds

12. Weak/Strong Electrolytes Strong Electrolytes- almost all of solute contains ions – Soluble salts (ionic compounds) – Strong acids/bases Weak Electrolyte- only fraction of the solute contains ions, poor electric currents – Weak acids/bases

13. Determine which are electrolytes or nonelectrolytes. If they are electrolytes, determine if it is weak or strong A. Acetic Acid (weak acid) B. Glucose (C 6 H 12 O 6 ) C. Sodium Hydroxide (strong base) D. Calcium Chloride (CaCl 2 ) E. Rubbing alcohol (C 3 H 7 OH)