Bronsted -Lowry base conjugate acid

Problem 32 The bicarbonate ion HCOj may serve as either a Bronsted-Lowry acid or base. When it acts as an acid, what is its conjugate base when it behaves as a base, what is its conjugate acid ... 

For each of the following reactions, identify the Bronsted-Lowry acids and bases and the conjugate acid-base pairs ... 

From this you can see that the cation from the salt comes from the base and the anion comes from the acid. Salts can act as Bronsted-Lowry acids or bases to produce solutions that are acidic or basic. The salts react with water in a reaction known as hydrolysis to yield either a conjugate acid and a hydroxide ion or a conjugate base and a hydrogen (hydronium) ion. If you know the origins of the components of a salt, you can make some predictions about the pH of the solution formed from a hydrolysis of a salt ion. 

Boundary potential, E, The resultant of two potentials that develop at the surfaces of a glass membrane electrode. Bronsted-Lowry acids and bases An acid of this type is defined as a proton donor and a base as a proton acceptor the loss of a proton by an acid results in the formation of a species that is a potential proton acceptor, or conjugate base of the parent acid. Buffer capacity The number of moles of strong acid (or strong base) needed to alter the pH of 1.00 L of a buffer solution by 1.00 unit. 

Butanoic acid, CFf3CFf2CFf2C02ff, is a monoprotic weak acid that is responsible for the smell of rancid butter. Write the formula for the conjugate base of this acid. Write the equation for the reaction between this acid and water, and indicate the Bronsted-Lowry acid and base for the forward reaction. (The acidic hydrogen atom is on the right side of the formula.)... 

Many organic compounds can act as weak Bronsted-Lowry acids or bases. Their reac- In the Bronsted-Lowry description, an tions involve the transfer of H+ ions, or protons (Section 10-4). Like similar reactions of acid is a proton donor and a base is a inorganic compounds, these acid-base reactions of organic acids and bases are usually fast proton acceptw. Review the terminology and reversible. Consequently, we can discuss the acidic or basic properties of organic of conjugate acid-base pairs in Section compounds in terms of equilibrium constants (Section 18-4). 

Choose 10 species that might be expected to behave as Bronsted-Lowry acids or bases in aqueous solution. For each of your choices, (a) write an equation demonstrating how the species behaves as an acid or base in water, and (b) write the formula of the conjugate base or acid for each of the species you have chosen. 

Once you become proficient at identifying conjugate acid-base pairs it is not difficult to write equations for reactions involving Bronsted-Lowry acids and bases (proton-transfer reactions). 

EXAMPLE 14.11 Identifying Bronsted-Lowry Acids and Bases and Their Conjugates... 

Conjugate base (Section 2.7) The product that results from deprotonation of a Bronsted-Lowry acid. 

Bronsted-Lowry acid, 49 conjugate base of, 49 strengths of, 50-52 Bronsted-Lowry base, 49 conjugate acid of, 49 strengths of, 50-52 Brown, Herbert Charles. 223 Butacetin, structure of. 833 1,3-Butadiene, 1,2-addition reactions of, 487-489... 

The equations can be readily expressed in a somewhat more general form when applied to a Bronsted-Lowry acid A and its conjugate base B ... 

When water acts as a Bronsted-Lowry acid, it donates a proton to another species, thereby converting to the hydroxide ion. HjO + H O OH + H3O" base acid conjugate conjugate base acid 1 point given for correct Bransted-Lowry concept of water being able to donate a proton, resulting in a hydroxide ion. 

To see what s going on in an acid-base reaction, keep your eye on the proton. For example, when a Bronsted-Lowry acid HA is placed in water, it reacts reversibly with water in an acid-dissociation equilibrium. The acid transfers a proton to the solvent, which acts as a base (a proton acceptor). The products are the hydronium ion, H30+ (the conjugate acid of H20), and A- (the conjugate base of HA) ... 

The second reactant is HF, and the first product is its conjugate base F -. The second product is H2S, and the first reactant is its conjugate base HS-. Therefore, the Bronsted-Lowry acids, bases, and conjugate acid-base pairs are as follows ... 

Give the formula for the conjugate base of each of the following Bronsted-Lowry acids ... 

Acyl chlorides are Bronsted-Lowry acids, and, just like aldehydes, they donate an a-hydrogen. The electron withdrawing chlorine stabilizes the conjugate base more than the lone hydrogen of an aldehyde, making acyl chlorides significantly stronger acids than aldehydes. 

For most aqueous acid-base chemistry, the Lewis definitions are too general and lack the symmetry of the acid-conjugate base relationship. We will mostly use the Bronsted-Lowry definitions. 

Sample In the chemical reaction shown below, identify the Bronsted-Lowry acid, Bronsted-Lowry base, conjugate acid, and conjugate base ... 

Bronsted-Lowry acid H20—donates a proton Bronsted-Lowry base NH3—accepts a proton Conjugate acid NH4+—formed by adding a proton to a base Conjugate base OH-—formed by removing a proton from an acid... 

When a Bronsted-Lowry acid donates a proton, the remaining anion is known as a conjugate base. When a Bronsted-Lowry base accepts a proton, the protonated base is known as a conjugate acid. 

A Bronsted-Lowry acid is any substance that is capable of donating a proton, whereas a Bronsted-Lowry base is any substance that is capable of accepting a proton. The loss of a proton by an acid gives rise to an entity that is a potential proton acceptor and thus a base it is called the conjugate base of the parent acid. Examples of acids reacting with bases are given in Table 1.16. The reactions listed in Table 1.16 are spontaneous in the direction that favors production of the weaker acid and base. Compounds that may act as bases and acids are referred to as amphoteric. 

T, F A conjugate base is formed from an acid that loses a proton. Bronsted-Lowry acids are proton donors and not acceptors. 

Treatment of indene with NaNH2 forms its conjugate base in a Bronsted-Lowry acid-base reaction. Draw aii reasonable resonance structures for indene s conjugate base, and explain why the pKa of indene is lower than the pK of most hydrocarbons. 

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