Net-ionic equation

Charles s and Gay-Lussac s law Relation stating that at constant P and n, the volume of a gas is directly proportional to its absolute temperature, 106-107, 111 Chelating agent Complexing ligand that forms more than one bond with a central metal atom the complex formed is called a chelate, 411-412 natural, 424-425 synthetic, 424-425 Chemical equation Expression that describes the nature and relative amounts of reactants and products in a reaction, 60-61. See also Equation, net ionic. 

The zinc anode and copper cathode of a Daniell cell are both metals, and can act as electrical conductors. However, some redox reactions involve substances that cannot act as electrodes, such as gases or dissolved electrolytes. Galvanic cells that involve such redox reactions use inert electrodes. An inert electrode is an electrode made from a material that is neither a reactant nor a product of the cell reaction. Figure 11.6 shows a cell that contains one inert electrode. The chemical equation, net ionic equation, and half-reactions for this cell are given below. 

An ionic equation that shows all of the particles in a solution as they realistically exist is called a complete ionic equation. Note that the sodium ions and the chloride ions are both reactants and products. Because they are both reactants and products, they do not participate in the reaction. Ions that do not participate in a reaction are called spectator ions and usually are not shown in ionic equations. Ionic equations that include only the particles that participate in the reaction are called net ionic equations. Net ionic equations are written from complete ionic equations by crossing out all spectator ions. For example, a net ionic equation is what remains after the sodium and chloride ions are crossed out of this complete ionic equation. 

Key Terms Formula equation Total ionic equation Net ionic equation... 

Conventional equation Net ionic equation Spectator spectator ion Total ionic equation Section 9.5 Activity series... 

Conventional equation, total ionic equation, net ionic equation, spectator ion... 

Equations such as this that exclude spectator ions, which take no part in the reaction, are referred to as net ionic equations. We will use net ionic equations throughout this chapter and indeed the entire text to represent a wide variety of reactions in water solution. Like all equations, net ionic equations must show... 

A standard method for prepanng sodium cyclopentadienide (CsHsNa) is by the reaction of cyclopentadiene with a solution of NaNH2 in liquid ammonia Write a net ionic equation for this reaction identify the acid and the base and use curved arrows to track the flow of electrons... 

A precipitation reaction occurs when two or more soluble species combine to form an insoluble product that we call a precipitate. The most common precipitation reaction is a metathesis reaction, in which two soluble ionic compounds exchange parts. When a solution of lead nitrate is added to a solution of potassium chloride, for example, a precipitate of lead chloride forms. We usually write the balanced reaction as a net ionic equation, in which only the precipitate and those ions involved in the reaction are included. Thus, the precipitation of PbCl2 is written as... 

The emphasis is on writing and balancing chemical equations for these reactions. All of these reactions involve ions in solution. The corresponding equations are given a special name net ionic equations. They can be used to do stoichiometric calculations similar to those discussed in Chapter 3. 

Write a net ionic equation for any precipitation reaction that occurs when solutions of the following ionic compounds are mixed. 

Click Coached Problems for a self-study module on net ionic equations. 

To write a net ionic equation, you first have to identify the ions. 

For any reaction in water solution, always start with a balanced net ionic equation. 

Although we have introduced net ionic equations to represent precipitation reactions, they have a much wider application. Indeed, we will use them for all kinds of reactions in water solution. In particular all of the chemical equations written throughout this chapter are net ionic equations. 

The approach followed in Chapter 3 to calculate mole-mass relations in reactions is readily applied to solution reactions represented by net ionic equations. 

For the reaction between solutions of sodium hydroxide and hydrogen fluoride, the net ionic equation is... 

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

The overall equation is obtained by summing those for the individual steps. Canceling species (OH-, HzO) that appear on both sides, we obtain the net ionic equation... 

The experimental setup for a titration is shown in Figure 4.7. The flask contains vinegar, a water solution of a weak organic add called acetic acid. A solution of sodium hydroxide of known concentration is added from a buret. The net ionic equation for the acid-base reaction that occurs is... 

In a redox reaction, one species loses (i.e., donates) electrons and is said to be oxidized. The other species, which gains (or receives) electrons, is reduced. To illustrate, consider the redox reaction that takes place when zinc pellets are added to hydrochloric acid (Figure 4.8). The net ionic equation for the reaction is... 

An easy way to recognize a redox equation is to note changes in oxidation number of two different elements. The net ionic equation... 

With the aid of Tables 4.1 and 4.2, write net ionic equations for acid-base reactions. (Example 4.6 Problems 29-36) 27,33... 

Decide whether a precipitate will form when the following solutions are mixed. If a precipitate forms, write a net ionic equation for the reaction,... 

Write a balanced net ionic equation for each of the following add-base reactions in water. 

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