Solubility rules: Answers to lab

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Solubility rules Answers to lab
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Br Cl CO32 NO3 OH PO43 SO32 SO42
Ag X X X X X X
Al3 X X X X
Ba2 X X X X
Ca2 X X X
Co2 X X X X
Cu2 X X X X
Fe3 X X X X
K
Na
Ni2 X X X X
NH4
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Answers 1 - 8

• Alkali metals (IA) 2. NH4
• NO3 4. Br , Cl , SO42
• NO3 6. Na or K or NH4
• Ag3PO4 AlPO4 Ba3(PO4)2
• Ca3(PO4)2 Co3(PO4)2 Cu3(PO4)2
• FePO4 Ni3(PO4)2
• Ca(NO3)2 Soluble rule 2
• FeCl3 Soluble rule 3
• Ni(OH)2 Insoluble rule 5
• AgNO3 Soluble rule 2
• BaSO4 Insoluble rule 4
• CuCO3 Insoluble rule 6

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Answer 9

• You have a mixture of Ba2, Pb2, Cu2, Na
• Which can be precipitated without the others?
• Use Cl , Br , or I to precipitate Pb2 (rule
  3)
• Filtering leaves Ba2, Cu2, Na
• Use SO42 to precipitate Ba2 (rule 4)
• Filtering leaves Cu2, Na
• Use OH (rule 5), or any of PO43, CO32, SO32,
  S2 (rule 6) to precipitate Cu2
• Since all Na compounds are soluble, this will
  stay in solution

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Determining net ionic reactions

• Step 1 Write formula for reactants and products
  using valences. Products are determined by
  switching ve and ve.
• Step 2 Determine if any products are insoluble
  (use solubility rules). Note all reactants must
  be soluble (i.e. aq) in order to mix.
• If all products are aqueous no reaction
• Step 3 Balance the equation
• Step 4 Write the ionic equation
• Step 5 Write the net ionic equation
• E.g. sodium phosphate calcium chloride

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Answers 10 i) and ii)

• i)
• (NH4)2S(aq) Pb(NO3)2(aq) ? PbS(s) 2NH4NO3(aq)
• 2NH4(aq) S2(aq) Pb2(aq) 2NO3(aq) ?
  PbS(s) 2NH4(aq) 2NO3(aq)
• Net S2(aq) Pb2(aq) ? PbS(s)
• ii) Co(NO3)2(aq) Na2SO4(aq) ? No reaction

Step 1 Write correct formulas Step 2 Determine
if any products are insoluble Step 3 Balance the
equation Step 4 Write the ionic equation Step
5 Write the net ionic equation
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Answers 10 iii) - vi)

• iii) AgNO3(aq) NaI(aq) ? AgI(s) NaNO3(aq)
• Ag(aq) NO3(aq) Na(aq) I(aq)
• ? AgI(s) Na(aq) NO3(aq)
• Net Ag(aq) I(aq) ? AgI(s)
• iv)Al(NO3)3(aq) 3KOH(aq) ? Al(OH)3(s)
  3KNO3(aq)
• Al3(aq) 3NO3(aq) 3K(aq) 3OH(aq)
• ? Al(OH)3(s) 3K(aq) 3NO3(aq)
• Net Al3(aq) 3OH(aq) ? Al(OH)3(s)
• v)Zn(NO3)2(aq) K2CO3(aq) ? ZnCO3(s) 2KNO3(aq)
• Zn2(aq) 2NO3(aq) 2K(aq) CO32(aq)
• ? ZnCO3(s) 2K(aq) 2NO3(aq)
• Net Zn2(aq) CO32(aq) ? ZnCO3(s)
• vi) KCl(aq) NaNO3(aq) ? No reaction

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