Acids And Bases 8.2

Acids Acids – a substance that produces hydrogen ions in a water solution. H+ When the acid dissolves in water H+ ions interact with the water to form H30+ which are called hydronium ions.

Properties of Acids Acids Tastes Sour Acids are Corrosive Can react strongly with some metals

Common Acids Acetic Acid – vinegar Acetlysalicylic acid – aspirin Carbonic acid – carbonated drinks Hydrochloric acid – stomach acid Sulfuric acid – car batteries

Bases Bases are identified by the production of a hydroxide ion in a water solution. OH-

Properties of Bases They complement or are the opposites of acids. Bases are crystalline solids when not dissolved Base solutions feel slippery and have a bitter taste Can be corrosive and cause severe burns

Common Bases Aluminum Hydroxide - Antacid Magnesium Hydroxide – laxative Sodium Hydroxide – Soap Ammonia – Cleaners and Fertilizers

pH pH – the measure of the concentration of H+ ions in a solution The greater the H+ concentration is the lower the pH and indicates a acidic solution The lower the H+ concentration is the higher the pH and indicates a basic solution 7 is considered neutral. The scale goes from 1 to 14.

Identifying Acids and Bases Indicators – an organic compound that changes color in acid and base.

Identifying Acids and Bases Litmus Paper – Blue litmus paper turns red under acidic conditions (pH below 4.5) Red litmus paper turns blue under alkaline conditions (pH above 8.3) pH Paper – turns a different color depending on pH

Identifying Acids and Bases Natural pH indicators Red Cabbage Red Beets Some Berries Some Flowers

Hydrangea

Neutralization Neutralization – a chemical reaction between an acid and a base that takes place in a water solution. Typically creates a more mild pH HCl + NaHCO3  NaCl + CO2 + H2O Can you think of where this reaction would be helpful?

Neutralization Heartburn - Antacid

Salts Salt – a compound formed when negatrive ions from an acid combine with the positive ions from a base acid + base  salt + water HCl + Ca(OH)2  CaCl2 + H2O What is the acid? ___________________ What is the base?___________________ What is the salt?____________________