Spectators

Writing the equation in the usual way directs too much attention to the atoms and not enough to the electrons We can remedy that by deleting any spec tator ions and by showing the unshared electron pairs and covalent bonds that are made and broken Both sodium hydroxide and sodium fluoride are com pletely ionized in water therefore Na" which ap pears on both sides of the equation is a spectator ion Hydrogen fluoride is a weak acid and exists as undissociated HF molecules in water... 

The transparency of methanol flames is usually a safety advantage in racing. In the event of fires, drivers have some visibiUty and the lower heat release rate of methanol provides less danger for drivers, pit crews, and spectators. 

Total (and spectated) chromium in chromium plating mists... 

Schauer, m. shudder, thrill, fit shower spectator inspector shed. 

Equations such as this that exclude spectator ions, which take no part in the reaction, are Spectator ions are in solution before,... 

The Na+ and N03 ions take no part in the reaction and so do not appear in the equation. Here again, we are dealing with spectator ions. ... 

Here, as always, spectator ions such as Na+ are not included in the net ionic equation. 

Most anions behave this way, except those derived from strong acids (Cl-, Br-, I-, N03 , C104-), which show little or no tendency to react with water to harm OH- ions. Like the cations listed in the left column of Table 13.5, they act as spectator ions as far as pH is concerned. 

Spectator ion An ion that, although present, takes no part in a reaction, 279,82-83, 372-373,399 Spontaneity of reaction concentration and, 465-467,475-476q entropy and, 453-458 free energy and, 458-471 pressure effects, 465-467,475-476q process, 451-453 redox, 489-490... 

Some readers may feel that I have been unduly optimistic (or just plain presumptuous) in writing this book, when I am not actually carrying out research on any of these metals. They may well be right, though I would point out that the spectator does get a different view of events on the sports fields to that obtained by the player. 

FIGURE 1.5 (a) Silver chloride precipitates immediately when sodium chloride solution is added to a solution of silver nitrate, (b) If we imagine the removal of the spectator ions from the complete ionic reaction (top), we can focus on the essential process, the net ionic reaction (bottom). 

Because the Na+ and N03 ions appear as both reactants and products, they play no direct role in the reaction. They are spectator ions, ions that are present while the reaction takes place but remain unchanged, like spectators at a sports event. Because spectator ions remain unchanged, we can simplify the chemical equation by canceling them on each side of the arrow in the ionic equation ... 

Canceling the spectator ions leaves the net ionic equation for the reaction, the chemical equation that displays the net change taking place in the reaction ... 

STRATEGY First, write and balance the complete ionic equation, showing all the dissolved ions as they actually exist in solution, as separate, charged ions. Insoluble solids are shown as complete compounds. Next, cancel the spectator ions, the ions that remain in solution on both sides of the arrow. 

A complete ionic equation expresses a reaction in terms of the ions that are present in solution a net ionic equation is the chemical equation that remains after the cancellation of the spectator ions. 

Table 1.1 summarizes the solubility patterns of common ionic compounds in water. Notice that all nitrates and all common compounds of the Group 1 metals are soluble so they make useful starting solutions for precipitation reactions. Any spectator ions can be used, provided that they remain in solution and do not otherwise react. For example, Table 1.1 shows that mercury(I) iodide, Hg2I2, is insoluble. It is formed as a precipitate when solutions containing Hg22+ ions and I ions are mixed ... 

Because the spectator ions are not shown, the net ionic equation will be the same when any soluble mercury(I) compound is mixed with any soluble iodide. 

The Na+ and NO, ions are spectators, and so they are omitted from the net ionic, equation. 

When the solution in Beaker 1 is mixed with the solution in Beaker 2, a precipitate forms. Using the following table, write the net ionic equation describing the formation of the precipitate, and then identify the spectator ions. 

The contents of Beaker 1 are mixed with those of Beaker 2. If a reaction takes place, write the net ionic equation and indicate the spectator ions. ... 

Each of the following five procedures results in the formation of a precipitate. For each reaction, write the chemical equations describing the formation of the precipitate the overall equation, the complete ionic equation, and the net ionic equation. Identify the spectator ions. 

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