Acids and Bases

Any compound that increases the number of hydronium ions, H3O+, when dissolved in water What is an ion? Hydronium forms when a hydrogen ion splits from the acid and bonds with a water molecule H+ + H20 -> H3O+ Acids

Properties of Acids Sour flavor Many corrosive- destroy body tissue, clothing; many also poisonous Indicator- changes color in presence of an acid Ex. Litmus paper React with some metals to produce hydrogen gas 2HCL + Zn -> H2 + ZnCl2 Conduct electric current Properties of Acids

Uses of Acids Sulfuric acid Nitric acid Hydrochloric acid Most widely made chemical in the world Used to make paper, paint, detergents, fertilizer Nitric acid Used to make fertilizer, rubber, & plastics Hydrochloric acid Used to make metals from their ores, to keep swimming pools free of algae, aids stomach in digestion, etch glass Citric & ascorbic acid Vitamin C, found in orange juice Carbonic & phosphoric acid Help give taste to soft drinks Uses of Acids

Any compound that increases the number of hydroxide ion, OH-, when dissolved in water Ex. Sodium hydroxide breaks apart to form sodium ions and hydroxide ions NaOH -> Na+ + OH- Bases

Properties of Bases Bitter flavor & slippery feel Many corrosive Indicators- changes color in presence of a base Conduct electric current Properties of Bases

Uses of Bases Soaps Bleach & detergent Baking soda Sodium hydroxide Used to make soap, paper, oven cleaner, drain unclogger Calcium hydroxide Used to make cement and plaster Ammonia Used in household cleaners & fertilizer Magnesium hydroxide & aluminum hydroxide Used in antacids Uses of Bases

Strength Strength not equal to concentration Concentration- amount of acid or base dissolved in water Strength- depends on # of molecules that break apart when dissolved in water Strength

Acid molecules break apart when dissolved in water producing hydrogen ions If all the molecules break apart, then strong acid Ex. Sulfuric acid, nitric acid, & hydrochloric acid If only a few molecules break apart, then weak acid Ex. Acetic acid, citric acid, & carbonic acid Strong vs. Weak Acids

If all molecules of a base break apart in water, producing hydroxide ions, then the base is strong. Ex. Sodium hydroxide, calcium hydroxide, & potassium hydroxide If only a few molecules break apart, then the base is weak Ex. Ammonium hydroxide & aluminum hydroxide Strong vs. Weak Bases

Reaction between acids & bases is a neutralization reaction Hydrogen ions react with hydroxide ions to form water H+ + OH- -> H2O Other ions from acid base solution dissolve in water & join together if water evaporates to form a compound of salt Neutralization

pH scale Used to identify how acidic or basic a solution is pH is a measure of hydronium ion concentration Water is neutral- pH 7 Acids- pH less than 7 Bases- pH greater than 7 pH scale

Salts When an acid neutralizes a base, salt & water are produced Salt- ionic compound formed from positive ion of base & negative ion of acid Ex. Sodium chloride- table salt Sodium nitrate- used to preserve food Calcium sulfate- used to make wallboard 10.4 Salts

Use the following terms to create a concept map comparing properties of acids & bases Neutral Base pH value greater than 7 pH value less than 7 Salt Hydroxide ions Neutralize Hydrogen ions Concept Map