Section 4: Acids and Bases in Solution Objectives: describe the ions formed when acids and bases are dissolved in water describe the pH scale and tell how it is used explain what happens in a neutralization reaction

Acids in Solutions An acid is any substance that produces hydrogen ions (H + ) in water

Bases in Solution A base is any substance that accept hydrogen ions such as those that produce hydroxide ions (OH + ) in water.

Strength of Acids and Bases Strength of an acid or base refers to how well an acid or base produces ions in water. Acids produce hydrogen ions (H+) while bases produce hydroxide ions (OH-).

Measuring pH The pH scale is a range of values from It is a measure of concentration of hydrogen ions. pH of 1 = very high hydrogen ions pH of 14 = very low hydrogen ions

Acid Rain Many industrialized countries use coal as their main source of energy. As coal burns, so does the sulfur that it contains. The sulfur dioxide oxidizes and combines with moisture in the air to form sulfuric acid droplets. In addition, nitrogen oxide from car exhaust combine with Moisture to make dilute nitric acid.

Acid rain can create many problems on earth including:

And destruction or damage of lakes and streams:

Common Antacids AntacidActive Ingredients TumsCaCO 3 (calcium carbonate), MgCO 3 (magnesium carbonate), Mg 2 Si 3 O 8 (Magnesium trisilicate) MaaloxSuspension of Mg(OH) 2 (magnesium hydroxide and Al(OH) 3 (aluminum hydroxide) in water RolaidsCaCO 3 (calcium carbonate) and Mg(OH) 2 magnesium hydroxide) Alka-SeltzerCa(H 2 PO 4 ) 2 (calcium dihydrogen phosphate), NaHCO 3 (sodium bicarbonate), citric acid, and aspirin.

Acid-Base Reactions Sometimes an acid-base reaction can produce a neutral solution.

Products of Acid-Base Reactions A neutralization reaction produces water and a salt.

Common Salts and Their Uses Salt NameFormulaMade From Base + Acid Uses Sodium chloride NaClNaOH + HCl Seasoning/food preservative Sodium bicarbonate NaHCO 3 NaOH + H 2 CO 3 Baking soda Calcium chloride CaCl 2 Ca(OH) 2 + HCl Drying agent/absorbs moisture Potassium nitrate KNO 3 KOH + HNO 3 fertilizer