Solubility Rules

C11-4-10 SOLUBILITY AND PRECIPITATION OUTCOME QUESTION(S): C11-4-10 SOLUBILITY AND PRECIPITATION Explain which factors can affect solubility of solids, liquids, and gases Differentiate among saturated, unsaturated, and supersaturated solutions using a graph of solubility data and solve problems Explain solubility and precipitation using balanced ionic and net ionic equations Use a table of solubility rules to predict the formation of a precipitate Vocabulary & Concepts  Spectator ion

Reactions produce new compounds with different solubility The ability for a given substance (solute), to dissolve in a solvent. Soluble and insoluble are relative terms Solubility curves for each compound are unique Reactions produce new compounds with different solubility soluble ? insoluble

Precipitation (ppt) Reaction: Formation of a compound that is insoluble or of low solubility in the current solvent. How do we know what will be undissolved (ppt)? Ppt reactions are typically SR or DR reactions soluble soluble soluble ppt AgNO3(aq) + NaCl(aq) NaNO3(aq) + AgCl(s) Spectator ions - do not precipitate, remain free as ions in solution

Basic Solubility Rules (View 1) All ionic compounds containing Group 1 elements, H+ and ammonium ion are soluble. All ionic compounds with Group VII elements (other than F) and metals are soluble, except those of Ag+, Hg+1, and Pb+2. All acetates and nitrates are soluble. All sulfates are soluble except those of Ba+, Sr+2, Pb+2, Ca+2, Ag+, Hg+1. Carbonates, hydroxides, oxides, sulfides, phosphates, chromates and dichromates are soluble; ONLY when bonded with those in rule. There are many different ways to present RULES for what will dissolve and what will NOT (ppt)

Most rules are based on identifying the anion of the compound first Basic Solubility Rules (View 2) Most rules are based on identifying the anion of the compound first

Use this one – found on the back of our Periodic Table Basic Solubility Rules (View 3) Use this one – found on the back of our Periodic Table

Assume the reactants will dissolve… Using the Solubility Rules: Assume the reactants will dissolve… Predict the products and complete the reaction Check RULES to determine if product(s) ppt NaCl(aq) + KBr(aq) NaBr(aq) + KCl(aq) Having no precipitate means “NO REACTION” since everything looks the same (dissolved) before and after

Indicate if any of the product form a precipitate (ppt). KOH(aq) + AgNO3(aq) KNO3(aq) + AgOH(s) (ppt) Indicate which compound precipitates (undissolved) by using the solid (s) phase Calcium nitrate + sodium carbonate Ca(NO3)2(aq) + Na2CO3(aq) CaCO3(s) + NaNO3(aq) 2 (ppt)

Indicate if any of the product form a precipitate (ppt). Na2SO4(aq) + KCl(aq) 2 2 NaCl(aq) + K2SO4(aq) No Reaction Iron (III) chloride + lead (II) nitrate 2 FeCl3(aq) + Pb(NO3)2(aq) 3 2 PbCl2(s) + Fe(NO3)3(aq) 3 (ppt)

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) Complete ionic equation: displays all ions in their dissociated form. Ag+(aq) + NO3−(aq) + Na+(aq) + Cl−(aq) → AgCl(s) + Na+(aq) + NO3−(aq) (ppt) Spectator ions Net ionic equation: shows actual (precipitation) reaction that occurs – no spectator ions. Ag+(aq) + Cl−(aq) → AgCl(s) Ask: what ions came together to form the precipitate?

Write the molecular equation and the net ionic equation for the reaction between aqueous lead (II) nitrate and aqueous potassium iodide. Molecular Equation: Pb(NO3)2(aq) + KI(aq) 2 PbI2(s) + KNO3(aq) 2 (ppt) Net Ionic Equation: Spectator ions K+ NO3− Pb2+(aq) + 2 I−(aq) → PbI2(s) Just pull the components (including coefficients) out of the completed molecular equation

C11-4-10 SOLUBILITY AND PRECIPITATION CAN YOU / HAVE YOU? C11-4-10 SOLUBILITY AND PRECIPITATION Explain which factors can affect solubility of solids, liquids, and gases Differentiate among saturated, unsaturated, and supersaturated solutions using a graph of solubility data and solve problems Explain solubility and precipitation using balanced ionic and net ionic equations Use a table of solubility rules to predict the formation of a precipitate Vocabulary & Concepts  Spectator ion