Hydroxide ions from base reacting with

Those ions which take no part in the reaction are known as spectator ions , and from these considerations, the following definitions can be derived. A basic oxide (or hydroxide) is a metallic oxide (or hydroxide) which contains the 02 (or OFT) ion it will react with an acid to form a salt and water only. It is necessary to realize the importance of the word only in this definition, as were it to be omitted, then certain compounds which are quite different from basic metallic oxides and hydroxides would be covered by this definition. Thus, Pb(IV) oxide reacts with hydrochloric acid to produce Pb(II) chloride (a salt) and water, but does not belong to the class of bases because chlorine gas is also produced ... 

As we saw above, chlorine forms hypochlorous acid, HOCI. The hydroxide ions generated from urea react with the hypochlorous acid in a typical acid-base reaction,... 

According to the Arrhenius definition of acids and bases, acids are substances that produce hydrogen ions (H+) in solution, and bases are substances that produce hydroxide ions (OH ) in solution. When an acid and a base combine, the hydrogen ions from the acid react with the hydroxide ions from the base to form water—a neutralization reaction. 

Bases provide hydroxide ions to aqueons solntion. Soluble metal hydroxides, including those of the alkali metals and barium, are examples. The soluble metal hydroxides are ionic even when they are pure solids they remain ionic in water. When they are dissolved in water, the hydroxide ions are totally separated from the metal ions. A soluble metal hydroxide is a strong base. A weak base is not 100% ionized. Ammonia, the most common weak base, reacts with water to a small extent to provide hydroxide ions ... 

How does neutralization occur Recall that every water molecule contains two hydrogen atoms and one oxygen atom. As Figure 21 shows, when one hydronium ion reacts with one hydroxide ion, the product is two water molecules. This reaction occurs during acid-base neutralization. Equal numbers of hydronium ions from the acidic solution and hydroxide ions from the basic solution react to produce water. Pure water has a pH of 7, which means that it s neutral. 

Even though the strong acid and strong base in Sample Problem 1 are different from those in the HCl reaction with NaOH, the net ionic equation is the same. Hydrogen ions from the acid react with hydroxide ions from the base to form water. This equation is always the net ionic equation for a strong acid-strong base reaction. 

The net ionic equation also shows why this reaction is called a neutralization reaction. The hydrogen ion from the acid reacts with the hydroxide ion from the base to form water, which is neutral. 

Strong bases are all composed of a cation and hydroxide ion. They are strong electrolytes. Weak bases react with water to make hydroxide ion, accepting a proton from water leaving free hydroxide ion in solution. They are weak electrolytes and exist in solution as an equilibrium between the molecular base and the ions it forms upon reaction with water. 

Polyatomic ions do not have their origin through direct electron transfer from element to element which we called oxidation-reduction reactions. It is important to recognize that ions can be formed in other types of chemical reactions. Most of the ions of interest to us arise from reactions in solutions, in which substances are dissolved in water. All the polyatomic ions described in Sec. 3.2.2 arose by reactions in water, either by reaction with the water itself or some other substance like the hydroxide ion, OH . For example, two substances HCl, hydrogen chloride, and NH j, ammonia, a base, react with water in the following way ... 

The phase-transfer catalyst is soluble in both water and the organic solvent. It is water soluble because it is an ion, and it is hexane soluble because of the three long-chain alkyl groups. Thus, the phase-transfer catalyst distributes itself in both phases, and freely shuttles back and forth through the phase boundary between solvent layers. In aqueous NaOH, the chloride anion exchanges with hydroxide anion, as the counterion to the ammonium cation. When it does this, the catalyst carries the hydroxide ion from the aqueous phase, as an ion-pair, across the phase boundary into the organic phase, where the base then reacts with the diethyl benzylphosphonate. The Homer-Wadsworth-Emmons reaction then occurs, producing the alkene and diethyl phosphate anion. This anion becomes associated with the ammonium cation of the phase-transfer catalyst and is transported to the aqueous layer, where the catalyst picks up another hydroxide ion and repeats the entire process. 

As an example of enolate-ion reactivity, aldehydes and ketones undergo base-promoted o halogenation. Even relatively weak bases such as hydroxide ion are effective for halogenation because it s not necessary to convert the ketone completely into its enolate ion. As soon as a small amount of enolate is generated, it reacts immediately with the halogen, removing it from the reaction and driving the equilibrium for further enolate ion formation. 

In the historical introduction to this book (Sec. 1.1) it was mentioned that the discoverer of diazo compounds, Peter Griess, realized quite early (1864 a) that these species could react with alkali hydroxides. Thirty years later Schraube and Schmidt (1894) found that the primary product from the addition of a hydroxide ion to a diazo compound can isomerize to form a secondary product. In this section we will discuss the equilibria of the first acid-base process of aromatic diazonium ions. In the following section additional acid-base reactions will be treated in connection with the isomerism of addition products of hydroxide ions to diazonium ions. 

In a neutralization reaction in water, an acid reacts with a base to produce a salt (and water if the base is strong) the net outcome of the reaction between solutions of a strong acid and a strong base is the formation of water from hydrogen ions and hydroxide ions. 

In one type of titration, a solution of a strong base such as sodium hydroxide is added slowly to a solution that contains an unknown amount of an acid. Each hydroxide ion added to the acid solution accepts one proton from a molecule of acid. As the titration proceeds, fewer and fewer acid molecules remain in the acid solution, but the solution is still acidic. At the stoichiometric point, just enough hydroxide ions have been added to react with every acidic proton present in the acid solution before the titration was started. The hydroxide ions in the next drop of titrant do not react because acid molecules are no longer present in the solution. Before the stoichiometric point, the solution contains excess acid. After the stoichiometric point, the solution contains excess OH". Figure 4-11 shows a titration setup and molecular views illustrating titration of a strong acid by a strong base. 

The formation of colloidal sulfur occurring in the aqueous, either alkaline or acidic, solutions comprises a serious drawback for the deposits quality. Saloniemi et al. [206] attempted to circumvent this problem and to avoid also the use of a lead substrate needed in the case of anodic formation, by devising a cyclic electrochemical technique including alternate cathodic and anodic reactions. Their method was based on fast cycling of the substrate (TO/glass) potential in an alkaline (pH 8.5) solution of sodium sulfide, Pb(II), and EDTA, between two values with a symmetric triangle wave shape. At cathodic potentials, Pb(EDTA)2 reduced to Pb, and at anodic potentials Pb reoxidized and reacted with sulfide instead of EDTA or hydroxide ions. Films electrodeposited in the optimized potential region were stoichiometric and with a random polycrystalline RS structure. The authors noticed that cyclic deposition also occurs from an acidic solution, but the problem of colloidal sulfur formation remains. 

When acids and bases come into contact with one another, a chemical reaction called a neutralization reaction takes place. A neutralization reaction is a double displacement reaction. In a double displacement reaction, the positive ions from one reactant take the place of the positive ions in the other reactant. For example, if hydrochloric acid and sodium hydroxide react with one another, the positive sodium ion in sodium hydroxide will take the place of the hydrogen ion in the hydrochloric acid ... 

Remember that an acid-base reaction is a double displacement reaction. Therefore, if sulfuric acid and potassium hydroxide are mixed, the positive ions trade places. The hydrogen ions from the sulfuric acid will react with the negative hydroxide ions to form water. Because a hydrogen ion has a charge of + 1 and a hydroxide ion has a charge of -1, they bond in a 1 1 ratio ... 

When reacting with a base, Zn(OH)2 dissolves by the formation of a complex, Zn(OH)42 . In the reaction with an acid, protons are transferred from H30+ to the hydroxide ions, forming water molecules that remain coordinated to the Zn2+ ion. 

The solution of a salt derived from a strong base and weak acid is basic because the anion of a weak acid reacts with water (hydrolysis) to form hydroxide ions. Consider the soluble salt NaCIO found in chlorine bleaches prepared by reacting NaOH, a strong base, and HC10, a weak acid. The salt dissociates completely in water and the conjugate base of the weak acid, CIO-, hydrolyzes, producing OH- ions. 

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