Solutions, Solubility Rates, and Acids/Bases

Solutions What is a Solution? Solubility: Homogeneous Mixture (Same throughout) Solubility: ability of a solute to dissolve in a solvent

Parts of a Solution Solute – Solvent – Part that does the dissolving. Part being dissolved in the solvent. ex: Sugar, Hot Chocolate, Salt Solvent – Part that does the dissolving. ex: Water (universal solvent)

Factors Affecting Solubility Polarity Substances are polar (have north & south) or nonpolar Likes will dissolve likes Temperature Increase solvent temperature increase solubility

Levels of Solutions Unsaturated – Holding little solute in much solvent Saturated – Holding as much solute at a given temperature Supersaturated – UNSTABLE – more solute in the solvent at a high temp.

Electricity & Solutions Electrolyte Solution that can conduct electricity Ex: Salt and Water Nonelectrolyte Solution that cannot conduct electricity Ex: Sugar and Water

Concentrated vs. Diluted Strong solutions Diluted Weak solutions “Watered Down”

Rates of Solutions (how to speed up a solution) Stirring Heating Powdering (increase surface area)

Shows how temperatures affect solubility of solutes Solubility Curve Shows how temperatures affect solubility of solutes

Solubility Curve

Using the Solubility Curve What compounds shows a decrease in solubility from 0ºC to 100ºC? Which salt is most soluble at 10ºC? Which salt is least soluble at 20ºC? Which salt show the least change in solubility from 0ºC to 100ºC? How many grams of potassium chloride (KCl) can be dissolved at 80ºC? At 50ºC, how much potassium chlorate (KClO3) can be dissolved in 300 grams of water? At 30ºC, 90 grams of sodium nitrate (NaNO3) is dissolved in 100 g of water. Is this solution saturated, unsaturated or supersaturated?

Acids Compounds that produces hydronium (H+) ions when dissolved in water Formula start with “H”

Acid Properties Sour Taste Corrosive Reacts violently with metals Electrolyte Burns the skin pH is 0 –6 Starts with “H”

Common Acids Weak Acetic acid (vinegar) Boric acid (eye washes) Strong HCl hydrochloric acid H2SO4 sulfuric acid HNO3 nitric acid Weak Acetic acid (vinegar) Boric acid (eye washes)

Bases Compound that produces hydroxide (OH--) ions when dissolved in water Formula ends in “OH”

Bitter Taste Corrosive Slippery Feel Dissolves Oils/Fats Base Properties Bitter Taste Corrosive Slippery Feel Dissolves Oils/Fats Will burn the skin pH 8 – 14 Ends in “OH”

Common Bases Strong ammonia soaps and detergents NaOH - sodium hydroxide (lye soap) KOH – potassium hydroxide Mg(OH)2 laxatives Weak deodorants ammonia soaps and detergents

How to Determine If A Compound is an Acid or Base? ACID’s Formula starts with “H” BASE’s Formula end in “OH” If it does neither then it is a SALT

Acid, Base or Salt? LiOH HCl NaCl NH4OH Ca3(PO4)2 H2SO4

Neutralization Definition: A process where an acid and base are chemically combined to form a salt and water.

Special Reaction: Neutralization When a reaction between an ACID and a BASE produced A SALT and WATER A Double Replacement Reaction HCl + NaOH  NaCl + H2O

pH Scale Acid Range: 0—6 Strong Acid: 0—2 Base Range: 8—14 Strong Base: 10—14 Water has a pH of 7 (neutral) Used to determine how acidic or basic something is From 0—14 (number line)

Indicators Blue Litmus Paper Acid—turns Red Base—no change Red Litmus Paper Acid—no change Base—turns Blue

Indicators pH Paper Phenolphthalein Acid—turns red, orange, yellow tints Base—turns blue-green to dark blue tints Phenolphthalein Acid—stays clear Base—turns hot pink