1. NEUTRALIZATION REACTIONS By Ms. Lan (Mar. 2012)

2. Neutralization Reactions • A chemical reaction in which an acid and base react to form an ionic compound (salt) and water. • The acid and base react to form products that have a pH closer to 7 than the reactants.

3. Predicting Products • Generally, neutralization reactions follow a double displacement reaction. • For our purposes, the products will always be water and an ionic compound/salt. acid + base  water + ionic compound • Ex. 1: HCl(aq) + NaOH(aq)  H2O(l) + NaCl(aq) • Ex. 2: H3PO4(aq) + 3 KOH(aq) ?? H3PO4(aq) + 3 KOH(aq) 3H2O(l) + K3PO4(aq)

4. Antacids • Stomach acid is required to digest food. The stomach is lined with mucous to protect the rest of the body from the stomach acid. • Sometimes the acid might “reflux” back into the esophagus or irritate the stomach lining. • Antacids can neutralize the stomach acid and provide relief. • Common antacids contain magnesium hydroxide, sodium bicarbonate and calcium carbonate. • 2HCl(aq) + Mg(OH)2(aq)  2H2O(l) + MgCl2(aq) • HCl(aq) + NaHCO3(aq)  CO2(g) + H2O(l) + NaCl(aq)

5. Neutralizing Chemical Spills • On Mar. 31, 2007 a trail carrying 150,000 L of sulfuric acid derailed and spilled some of the acid in a river. • To neutralize the acid leaking from their containers, calcium oxide (lime), CaO(s),was added to the river upstream from the spill site. • Lime neutralized the acid in 2 steps: • 1) CaO(s) + H2O(l) Ca(OH)2(aq) • 2) Ca(OH)2(s) + H2SO4(aq)  2H2O(l) + CaSO4(aq) HMWK: Pg. 281 # 1 – 9