Warm Up – March 28, 2018 COPY QUESTIONS AND ANSWERS INTO NOTEBOOK! 1. The attraction between water molecules – adhesion or cohesion? 2. The substance that does the dissolving – solute or solvent 3. Two liquids that are soluble in each other – miscible or immiscible 4. A substance that does not dissolve in a solvent – soluble or insoluble 5. 2 or more substances mixed and you cannot tell them apart – homogenous or heterogeneous? 6. What do we call the attraction between particles – alloy or polarity

Dissociation and Solvation

DISSOCIATION: separation of molecules or ions of solute Ex. NaCl → Na+ + Cl- compound IONS

SOLVATION: solvent particles surround solute particles Draw these

(surface area) (agitate) Polar/nonpolar

Electrolyte vs. Nonelectrolyte

Draw/label this picture in the space to the right of your definition ELECTROLYTE- aqueous solution that conducts electricity (ions move around freely-ionic or acidic compounds) Draw/label this picture in the space to the right of your definition

Draw/label this picture in the space to the right of your definition NONELECTROLYTE- aqueous solution that does NOT conduct electricity (no ions-covalent compounds) Draw/label this picture in the space to the right of your definition

Demo: C12H22O11 vs. 2 NaCl solutions (They contain different amounts of NaCl dissolved in water) Draw each set-up

temperature and pressure (gases only) SOLUBILITY- amount of solute that will dissolve in a certain amount of solvent at a specific temperature and pressure (gases only) (under the line) Unsaturated-solution could hold more solute; below the line Saturated-solution has ‘just the right’ amount of solute; on the line Supersaturated-solution has ‘too much’ solute dissolved in it; above the line *ROCK CANDY*

How much solute will dissolve? A solubility curve shows the amount of each solute that will dissolve in 100g H20 at each temperature. Saturated is on the line. Unsaturated is below the line. Supersaturated is above the line. Saturated Grams solute/100 g H2O

How much NaClO3 would you have to add to 100 g of water at 50oC to make a saturated solution? Look at the intersection. Grams solute/100 g H2O

What is the solubility of KNO3 at 60 oC in 200 g of H2O? Grams solute/100 g H2O NaClO3 KNO3 KBr NaCl Temperature What is the solubility of KNO3 at 60 oC in 200 g of H2O? How many grams of KBr can dissolve in 50 grams of H2O at 100 oC?

Factors that affect Solubility 1. type of solute or solvent (like dissolves like) Ionic solutes tend to dissolve in polar solvents but not in nonpolar solvents Molecular solutes tend to dissolve in nonpolar solvents. 2. Temperature Direct Indirect Solid/liquid relationship? Gas relationship? 3. Pressure No effect Solid/liquid relationship? Gas relationship? Indirect

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