9.2 Reactions of Acids with Bases D12 - Explain the chemical composition of acids and bases, and explain the change of pH in neutralization reactions. What is neutralization? This is a chemical reaction between an acid and a base. When neutralization occurs, there are two products formed … 1. salt 2. water What is the ion formed by acids in water? Hydrogen ion H+ or Hydronium ion H3O+ What is the ion associated with bases? Hydroxide ion OHWhat happens when these two molecules get together? H3O+ + OH2H2O H+ + OHH2O Remember … not every salt is the “salt” that you are thinking about! A “salt” is any ionic compound formed from a cation (positive ion) and an anion (negative ion). While table salt (NaCl) is a “salt,” it is certainly not the only one out there! The example of Hydrochloric acid + Sodium hydroxide (base) ACID + BASE SALT + WATER HCl + NaOH NaCl + H2O = Salt water! KOH + HNO3 H2O + KNO3 Acid? HNO3 Base? KOH Salt? KNO3 NH3 + H2O NH4+ + OHBase – because OH- is present in the products HClO + LiOH LiClO + H2O Neutralization – because of the salt and water in the products HCl + H2O H3O+ + ClAcid – because H3O+ is present in the products No. Remember that it takes one H+ (or H30+) to cancel out one OH-. So, unless the amount of H+ from the acid and the OH- from the base are balanced, the resulting solution will not be neutral. The pH of final solution depends on the amounts and strength of the acid and base. If there is more OH- present than H+, the resulting solution will be basic. If there is more H+ present than OH-, the resulting solution will be acidic. What would result from mixing equal amounts of a weak base and a strong acid? An acidic solution Remember, a salt is another name for an ionic compound, which is a combination of cations and anions. Common salts: Table salt - NaCl Baking soda – NaHCO3 Highway de-icers – often CaCO3 and MgCl2 Fire extinguishers – NaHCO3, KHCO3 and ((NH4)H2PO4 Antiperspirants and deodorants - AlK(SO4)2 Minerals are inorganic elements that come from the soil and water. Your body needs minerals to grow and stay healthy. Minerals contain salts of elements that are needed by your body Ca – strong bones and teeth, nerves and muscles K and Na – nerve impulses, water content of cells P – transportation of energy, DNA replication We will use our knowledge of acids and bases to understand acid rain.