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Predicting the Products of Double Replacement Reactions. Using a Solubility Table. Introduction. Double replacement reactions are reactions that occur in solution. Cations and anions change places in double replacement reactions. One product must be: solid (precipitate) insoluble gas
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Predicting the Products of Double Replacement Reactions Using a Solubility Table
Introduction • Double replacement reactions are reactions that occur in solution. • Cations and anions change places in double replacement reactions. • One product must be: • solid (precipitate) • insoluble gas • water
Basics • Double replacement reactions have the following form: AX(aq) + BY(aq) → AY(s) + BX(aq) • For example: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq) Pb(NO3)2(aq) + 2 HCl(aq) → PbCl2(s) + 2 HNO3(aq) KOH(aq) + HBr(aq) → H2O(l) + KBr(aq)
Basics • In each of these reactions, the cations and anions change partners: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq)
Basics • In each of these reactions, the cations and anions change partners: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq)
Basics • In each of these reactions, the cations and anions change partners: BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaCl(aq)
Basics • Again, one of the products must be: • a precipitate (indicated by (s) or ↓) • an insoluble gas (indicated by (g) or ↑) • water (from the reaction of an acidwith a base) • We will be looking at those reactions which form (or don’t form) precipitatesas products
Solubility • Solubility is the ability of a compound, called the solute, to dissolve in a liquid, called the solvent. • Different compounds have different solubilities. • We are interested in those compounds that are not very soluble. • We want to know which ones form precipitates.
Solubility • We have a set of guidelinesfor the solubility of ionic compounds in water. • The guidelines tell us whether or not a particular family of ionic compounds is soluble. • We can use these guidelines to predict the formation of a participatein a potential double replacement reaction. • If no precipitate forms, then there is no reaction.
Solubility Guidelines • Most sodium, Na+, potassium, K+, and ammonium, NH4+, compounds are solublein water. • Most nitrate, NO3−, acetate, CH3COO−, and chlorate, ClO3−, compounds are solublein water. • Most chloride, Cl−, compounds are soluble, except those of silver, AgCl, mercury(I), Hg2Cl2, and lead, PbCl2. Lead(II) chloride is soluble in hot water. • Most sulfate, SO42−, compounds are soluble, except those of barium, BaSO4, strontium, SrSO4, and lead, PbSO4. • Most carbonate, CO32−, phosphate, PO43−, and silicate, SiO32−, compounds are insoluble, except those of sodium, potassium, and ammonium. • Most sulfides, S2−, compounds are insoluble, except those of calcium, Ca2+, strontium, Sr2+, sodium, Na+, potassium, K+, and ammonium, NH4+.
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Pb(NO3)2 PbSO4 Na2SO4 Na2SO4 NaNO3 We know that two of the possible precipitates are soluble. These are already in solution.
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Next, we look at the solubility guidelines PbSO4 Na2SO4 Most Na+, K+, and NH4+ compounds are soluble in water. NaNO3 NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Next, we look at the solubility guidelines PbSO4 Na2SO4 Most NO3–, CH3COO–, and ClO3– compounds are soluble in water. NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Next, we look at the solubility guidelines PbSO4 Na2SO4 Most Cl– compounds are soluble, except those of Ag+, Hg22+, and Pb2+. NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Next, we look at the solubility guidelines PbSO4 Na2SO4 Most SO42– compounds are soluble, except those of Ba2+, Sr2+, and Pb2+. NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 Next, we look at the solubility guidelines PbSO4 Na2SO4 PbSO4 will be a precipitate. NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 We now complete the equation. PbSO4 Na2SO4 PbSO4 will be a precipitate. NaNO3
Applications Example 1. Predict the result of mixing a solution of lead(II) nitrate with sodium sulfate. Pb(NO3)2(aq) + Na2SO4(aq) → PbSO4(s) + 2 NaNO3(aq) Cations Anions Possible precipitates Pb2+ NO3– Na+ SO42– Pb(NO3)2 We now complete the equation. PbSO4 Na2SO4 PbSO4 will be a precipitate. NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 CuCl2 NaCl NaCl NaNO3 We know that two of the possible precipitates are soluble. These are already in solution.
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 Next, we look at the solubility guidelines CuCl2 NaCl NaCl Most Na+, K+, and NH4+ compounds are soluble in water. NaNO3 NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 Next, we look at the solubility guidelines CuCl2 NaCl NaCl Most NO3–, CH3COO–, and ClO3– compounds are soluble in water. NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 Next, we look at the solubility guidelines CuCl2 CuCl2 NaCl NaCl Most Cl– compounds are soluble, except those of Ag+, Hg22+, and Pb2+. NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 Next, we look at the solubility guidelines CuCl2 CuCl2 NaCl NaCl There is no precipitate and no reaction. NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 We now complete the equation. CuCl2 CuCl2 NaCl NaCl There is no precipitate and no reaction. NaNO3
Applications Example 2. Predict the result of mixing a solution of copper(II) nitrate with sodium chloride. Cu(NO3)2(aq) + NaCl(aq) → no reaction Cations Anions Possible precipitates Cu2+ NO3– Na+Cl– Cu(NO3)2 Cu(NO3)2 We now complete the equation. CuCl2 CuCl2 NaCl NaCl There is no precipitate and no reaction. NaNO3
Practice Problems Predict the result of mixing each of the following solutions. • AgNO3(aq) + NaCl(aq) → • Cu2SO4(aq) + Na2CO3(aq) → • BaCl2(aq) + CuSO4(aq) → • Pb(CH3COO)2(aq) + Na3ClO3(aq) → • FeCl2(aq) + CaS(aq) → AgCl(s) + NaNO3(aq) CuCO3(s) + Na2SO4(aq) BaSO4(s) + CuCl2(aq) no reaction FeS(s) + CaCl2(aq)