5.2 Salts By the end of section 5.2 you should be able to understand the following: Salts are compounds that include the ionic compounds that form when acids and bases react. When acids and bases react, the process is called neutralization. Forms a salt and a water. Oxides reacting with acids, and carbonates reacting with acids, can also form salts. Metal oxides react with water to form bases, and non-metal oxides react with water to form acids.

Salt crystals in Death Valley 5.2 Salts Salts are ionic compounds formed when: Acids + bases react Oxides or carbonates react with acids Metals react with acids. Table salt, (NaCl) is only one kind of salt: is found in seawater, salt lakes or rock deposits. Salts are found in many things: in batteries, explosives, fertilizers, multivitamins and many living cells Salt crystals in Death Valley

Acid-Base Neutralization Neutralization reactions occur when an acid and a base react to produce a salt and water. HCl(aq) + NaOH(aq)  NaCl(s) + H2O( ) acid base salt water Balance the following neutralization reaction. H2SO4 + Al(OH)2  Al2(SO4)3 + H2O

Acids and Carbonates Carbonates (CO3) neutralize acids, protecting locations with natural carbonate supplies from acid precipitation. H2SO4(aq) + CaCO3(s)  CaSO4(s) + H2O(l) + CO2(g) sulphuric calcium calcium water carbon acid carbonate sulphate dioxide (egg shells and bones contain calcium carbonate – try putting an egg or chicken bone in vinegar for 3 days!)

Acids and Metals The most reactive metals, at the bottom of groups 1 and 2, react vigorously with water and acids. http://www.teachersdomain.org/resource/lsps07.sci.phys.matter.metalshcl/ When metals do react with acids, H2 gas is usually released and a salt is formed. 2HCl(aq) + Mg(s)  MgCl2(s) + H2(g)

Oxides (Metal/Non-Metal) What are oxides? At least 1 Oxygen atom or ion + One or more other elements. Both metals and non-metals can form oxides

Oxides (Metal/Non-Metal) Metal oxides react with water to form bases. Na2O(s) + H2O( )  2NaOH(aq) Metal oxides are used in making fireworks YOU TUBE: http://www.youtube.com/watch?v=l9z5-mJ8NZk&feature=related

Non-metal oxides react with water to form acidic solutions SO2(g) + H2O( )  H2SO3(aq) Non-metal oxides (SO2, NO2) are formed from the burning of fossil fuels Add water in the atmosphere = acid precipitation The effects of acid rain on a forest

Summary 1. Acids + Bases  2. Acids + Carbonates  3. Metal + Acid  4. Metal oxide + water  5. Non-metal oxide + water 