Bronsted-Lowry concept

On the above basis it is, in principle, unnecessary to treat the strength of bases separately from acids, since any protolytic reaction involving an acid must also involve its conjugate base. The basic properties of ammonia and various amines in water are readily understood on the Bronsted-Lowry concept. 

The Bronsted-Lowry concept of acids and bases4 makes it unnecessary to distinguish between acid and base indicators emphasis is placed upon the charge types of the acid and alkaline forms of the indicator. The equilibrium between the acidic form InA and the basic form InB may be expressed as ... 

Water can provide both H and OH H O H"+OH- According to Bronsted-Lowry theory, a water molecule can accept a proton, thereby becoming a hydronium ion. In this case, water is acting as a base (proton acceptor). H2O + H" H3O" 1 point given for correct Bronsted-Lowry concept of water being able to accept a proton resulting in a hydronium ion. 

The base in the Bronsted-Lowry concept is any substance that can accept the proton it can even be the solvent. A Bronsted-Lowry base has an electron pair (a lone pair) that will accept the proton. The point that needs to be stressed here is that the proton is involved in both the definition of an acid (donates a proton) and a base (1accepts a proton). 

The Bronsted-Lowry concept looks at the equilibrium reaction and ties the acid on the left to a base on the right, called a conjugate acid-base pair or, more simply, a conjugate pair. Suppose we were to consider an acid reacting with a compound in equilibrium with the acid s anion and the products, as... 

Note that HA and B are not necessarily neutral. They could be ions that are capable of acting as an acid or a base. This is one of the features of the Bronsted-Lowry concept that broadens the definitions of acids and bases over the Arrhenius concept—there are many more substances that can behave as acids or bases. Further, we can write the reaction including the solvent, water in this case, and the associated Ka. 

Definition According to Bronsted-Lowry concept an acid is a molecule that can donate a proton and a base is a molecule that can accept that proton. 

The Bronsted-Lowry concept of acids and bases will be discussed in detail in Chapter 7. 

Arrhenius concept, 534, 535, 536 Bronsted-Lowry concept, 536, 536 537-538, 537f, 558 examples of, 533 533f neutralization reactions of, 548-549, 548f, 549f, 550... 

The Bronsted-Lowry concept describes many more processes as acid-base reactions than does the Arrhenius concept. For example, the ionization of hydrogen chloride gas as it dissolves in water, HC1 (g) — HC1 (aq), can be described as an acid-base process as the proton from HC1 is transferred to water. 

Clearly, ammonia is a Bronsted-Lowry base, it accepts a proton, but it is also a substance that forms hydroxide ion when dissolved in water, so it qualifies as an Arrhenius base too. The equation given earlier showing HC1 (aq) in water shows HCl(aq) to be an acid in both the Arrhenius and Bronsted-Lowry concepts. 

In terms of the Bronsted-Lowry concept, define an acid, a base and neutralization. 

Using words and a single chemical equation, show how nitric acid, HNO3(aq), is classed as an acid in both the Arrhenius and Bronsted-Lowry Concepts. 

Nitric acid ionizes in water to produce hydrogen ion, which exists in water as the hydronium ion. This makes it an Arrhenius acid. The equation showing the formation of the hydronium ion, H30+, shows nitric acid as a proton donor, making it an acid in the Bronsted-Lowry concept. 

Why is ammonia, NH3, considered to be a base in both in the Arrhenius and Bronsted-Lowry concepts of acids and bases ... 

In the Bronsted-Lowry concept, an acid is a proton donor, a base a proton acceptor and neutralization is the donation of one proton by an acid to a base. 

Bronsted-Lowry concept (14) An acid-base concept that defines an acid as a proton donor and a base as a proton acceptor. Neutralization is the transfer of a proton from an acid to a base. 

In terms of the Bronsted-Lowry concept of acids and bases, identify the acid, base, conjugate acid, and conjugate base in the following equation ... 

Because the emphasis in the Bronsted-Lowry concept is on proton transfer, the concept also applies to reactions that do not occur in aqueous solution. In the reaction... 

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