Double Replacement Reactions

Double Replacement Reactions Two ionic compounds react to form two new ionic compounds; “switching partners” AB + CD  CB + AD The result of this reaction produces two new compounds, one of which is a precipitate, water, or gas

Double Replacement Reactions Cations switch places with cations OR think of it as “metals switching with metals” 3 CaCl2 + 2 AlN  2 AlCl3 + Ca3N2

Double Replacement Reactions Each compound formed must be checked to see if it is a gas, precipitate, or water Gas = (g) Precipitate = (s) Aqueous Solution (solvent is water) = (aq) Liquid = (l)

Double Replacement Reactions Check your solubility chart… If your chart reads “I” that means that the compound in insoluble and is a solid precipitate which means you should write (s) If your chart reads “S” that means that the compound is soluble in water, or aqueous, which means you should write (aq)

Double Replacement Reactions If a gas, water, or precipitate is not formed, the reaction will not take place Formation of a precipitate - AgNO3(aq) + NaCl(aq)  NaNO3(aq) + AgCl(s) Formation of a gas - FeS(s) + 2 HCl(aq)  2 H2S(g) + FeCl2(aq) Formation of water - HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l)

Combustion Reactions Occurs when a hydrocarbon combines with oxygen gas in the air – burning Combustion of Propane C3H8(g) + 5 O2(g)  3 CO2(g) + 4 H2O(g)