Predicting the weather is tricky business. A thorough examination of a large amount of data is needed to make the daily forecast. Wind patterns, historical data, barometric pressure—these and many other data are fed into computers that then use a set of rules to predict what will happen based on past history. Some combinations of aqueous reactants result in the formation of a solid precipitate as a product. However, some combinations will not produce such a product. If solutions of sodium nitrate and ammonium chloride are mixed, no reaction occurs. One could write a molecular equation showing a double-replacement reaction, but both products, sodium chloride and ammonium nitrate, are soluble and would remain in the solution as ions. Every ion is a spectator ion and there is no net ionic equation at all. It is useful to be able to predict when a precipitate will occur in a reaction. To do so, you can use a set of guidelines called the solubility rules (shown in Table \(\PageIndex{1}\)). For practice using the solubility rules, predict if a precipitate will form when solutions of cesium bromide and lead (II) nitrate are mixed. \[\ce{Cs^+} \left( aq \right) + \ce{Br^-} \left( aq \right) + \ce{Pb^{2+}} \left( aq \right) + 2 \ce{NO_3^-} \left( aq \right) \rightarrow ?\nonumber \] The potential precipitates from a double-replacement reaction are cesium nitrate and lead (II) bromide. According to the solubility rules table, cesium nitrate is soluble because all compounds containing the nitrate ion, as well as all compounds containing the alkali metal ions, are soluble. Most compounds containing the bromide ion are soluble, but lead (II) is an exception. Therefore, the cesium and nitrate ions are spectator ions and the lead (II) bromide is a precipitate. The balanced net ionic reaction is: \[\ce{Pb^{2+}} \left( aq \right) + 2 \ce{Br^-} \left( aq \right) \rightarrow \ce{PbBr_2} \left( s \right)\nonumber \] SummaryLICENSED UNDER Recommended textbooks for you Chemistry Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste Publisher:Cengage Learning Chemistry Author:Raymond Chang Dr., Jason Overby Professor Publisher:McGraw-Hill Education Principles of Instrumental Analysis Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch Publisher:Cengage Learning Organic Chemistry Author:Janice Gorzynski Smith Dr. Publisher:McGraw-Hill Education Chemistry: Principles and Reactions Author:William L. Masterton, Cecile N. Hurley Publisher:Cengage Learning Elementary Principles of Chemical Processes, Bind... Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard Chemistry ISBN:9781305957404 Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste Publisher:Cengage Learning Chemistry ISBN:9781259911156 Author:Raymond Chang Dr., Jason Overby Professor Publisher:McGraw-Hill Education Principles of Instrumental Analysis ISBN:9781305577213 Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch Publisher:Cengage Learning Organic Chemistry ISBN:9780078021558 Author:Janice Gorzynski Smith Dr. Publisher:McGraw-Hill Education Chemistry: Principles and Reactions ISBN:9781305079373 Author:William L. Masterton, Cecile N. Hurley Publisher:Cengage Learning Elementary Principles of Chemical Processes, Bind... ISBN:9781118431221 Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard Publisher:WILEY |