Acids, Bases and Salts BASES ACIDS SALTS

ACIDS = “acidus” (latin word) meaning sour. The word acids comes from one of its characteristic properties, its taste. ACIDS = “acidus” (latin word) meaning sour.

Acids An acid is a substance that releases H+ ions in an aqueous solution An aqueous solution is a solution that contains water. HCl  H+ + Cl-

Bases BASES Bases are substances that are very slippery to touch and have a strong bitter taste.

Bases A base is a substance that releases OH- ions in an aqueous solution NaOH  Na+ + OH-

Salts are formed by the bonding of a metal with a non-metal. They are often used to change the physical properties of various solutions by lowering the freezing points or raising the boiling points

Salts Salts dissolve in water to produce ions (not including H+ or OH-) NaCl  Na+ + Cl-

(USED TO DETECT ACIDS OR BASES) INDICATORS (USED TO DETECT ACIDS OR BASES) Litmus paper is a type of indicator (thin strip of paper that is dipped into a solution) 2 Types: Blue Litmus Paper Red Litmus Paper ACIDS – Turn blue litmus paper red BASES – Turn red litmus paper blue BB

Indicators SALTS – most salts are neutral

Indicators INDICATORS An indicator is a chemical used to tell if a liquid is an acid, base or neutral Phenolphthalein is another type of indicator Bases turn clear phenolphthalein pink INDICATORS

Properties of Acids, Bases and Salts Electrolyte Magnesium Taste/ Touch Litmus Paper ACID H+ ions YES Reaction to produce hydrogen Sour Turns red BASE OH- ions No Reaction Bitter/ Slippery Blue SALT Other ions Salty No change in colour Electrolytes – solutions that conduct electricity

NEUTRALIZATION ACID - BASE - “Making a solution chemically neutral” Chemically neutral – means does not contain an acid or base ACID - Neutralize it with a base BASE - Neutralize it with an acid Acids and bases neutralize each other forming a salt and water Ex. Acid + Base = Salt + water

REMEMBER... Acids, bases and salts conduct electricity Tap water will conduct (free ions around) Distilled water does not conduct (no free ions!)

Depends on the solution KEY POINTS Review chart: (very important!) Electrical Conductivity Magnesium Taste/ Touch Litmus Paper ACID YES Reaction Sour Turns red BASE No Reaction Bitter/ Slippery Blue SALT Salty Depends on the solution

PRACTICE PROBLEMS Worksheet # 1 Study guide, Module 3, page 2