Equation acid-base reactions

Cleavage of a carbon-hydrogen bond to yield a carbanion and proton is a Bronsted acid-base reaction (Equations 5.24 and 5.25). The mechanism is not... 

This contrasts markedly to the fact that no other reagent in water solution has more than just a secondary effect on the rate the leaving group is released. There has been much discussion as to the mechanism of base hydrolysis. Various types of evidence have been obtained which agree with a mechanism that involves first a rapid acid-base reaction (Equation 5), followed by the rate determining dissociation of the amido complex (Equation 6), and finally the rapid addition of water (Equation 7). 

Taking into account the equilibrium molalities of the substances participating in the acid-base reaction, equation (2.4.15) can be rewritten in the form ... 

Porphyrins have four inner nitrogens and show four stepwise acid-base reactions (equation 1). The pAT, and pATj values are estimated to be 16, piTj is 5, and pA 4 is 2 for j -alkylated porphyrins. Because of N protonation, electrophilic meso deuteration of metal-free porphyrins is slower in strong acids (HjOEP in TFA-d, Ti,2 = 275h at 90 °C) than in weak acids (ti/2 = 140 14 min in refluxing AcOD). Metalloporphyrins are more easily deuterated in strongly acidic media, e.g. M(OEP) (M = Fe, Cu, Pt) are completely meso-deuterated in TFA-Ji CDCl3 (1 1) at room temperature within 20 min. Meso deuteration of M(OEP) is possible under basic conditions (Mgl -DjO or MeOD-hot pyridine). ... 

Note that it is assumed that i/Tq = 1/ 2, that is, the Stern layer is disregarded. If the acid-base reactions (Equations 5.1 and 5.2) are at equilibrium, the surface potential is given by the Nernst equation,... 

Consider first the case of adding a strong acid such as HBr to water The equation for the Brpnsted acid-base reaction that occurs between them is... 

The evolution of caibon dioxide essentially follows the stoichiometiy of acid—base reactions. Baking soda determines the amount of carbon dioxide evolved, whereas the type of acid controls the speed of hberation. The reaction equations for some acids with baking soda ate as follows ... 

When an acidic water solution is mixed with a basic water solution, an acid-base reaction takes place. The nature of the reaction and hence the equation written for it depend on whether the add and base involved are strong or weak. 

Strategy Decide whether the add and base are strong or weak. Then decide which of the three types of acid-base reactions is involved. Finally, use Table 4.2 to derive the proper 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 earlier sections of this chapter, we showed how to write and balance equations for precipitation reactions (Section 4.2) and acid-base reactions (Section 4.3). In this section we will concentrate on balancing redox equations, given the identity of reactants and products. To do that, it is convenient to introduce a new concept, oxidation number. 

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... 

For an acid-base reaction, what is the reacting species, that is, the ion or molecule that appears in the chemical equation, in the following acids ... 

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

For which of the following pairs would this be the correct prototype equation for the acid-base reaction in solution If it is not correct, write the proper equation for the acid-base reaction between the pair. 

Acid-base indicator, 403-404q colors, 392-393 equivalence point and, 84 Acid-base reactions, 96-97q, 402q amino acids, 622-625 Brensted-Lowry model, 353-354 buffer systems, 383-391 equations for, 82-84 Lewis acid in, 410 Lewis base in, 410 types, 81-82... 

Bronsted acid/base catalysis (equation, a, p) 113, 210, 355ff.,360ff., 392 Buckminsterfullerene, reaction with ArN 188... 

Balance each of the following skeletal equations and classify the reaction as Bronstcd-I. owry acid-base, Ix wis acid-base, or redox. For both types of acid-base reactions, identify the acid and the base. For redox reactions, identify the reducing agent and the oxidizing agent. 

According to this theory, an acid is defined as a proton donor and a base as a proton acceptor (a base must have a pair of electrons available to share with the proton this is usually present as an unshared pair, but sometimes is in a 7t orbital). An acid-base reaction is simply the transfer of a proton from an acid to a base. (Protons do not exist free in solution but must be attached to an electron pair). When the acid gives up a proton, the species remaining still retains the electron pair to which the proton was formerly attached. Thus the new species, in theory at least, can reacquire a proton and is therefore a base. It is referred to as the conjugate base of the acid. All acids have a conjugate base, and all bases have a conjugate acid. All acid-base reactions fit the equation... 

In this equation, r) the absolute hardness, is one-half the difference between /, the ionization potential, and A, the electron affinity. The softness, a, is the reciprocal of T]. Values of t) for some molecules and ions are given in Table 8.4. Note that the proton, which is involved in all Brdnsted acid-base reactions, is the hardest acid listed, with t — c (it has no ionization potential). The above equation cannot be applied to anions, because electron affinities cannot be measured for them. Instead, the assumption is made that t) for an anion X is the same as that for the radical Other methods are also needed to apply the treatment to polyatomic... 

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