Bronsted-Lowry base A substance

Bronsted-Lowry base A substance that can accept H+... 

Bronsted-Lowry Base A substance that accepts protons, H" ", in a Bronsted-Lowry acid-base reaction. 

Bronsted-Lowry acid A substance capable of donating protons. See acid-base pair, conjugate proton. Bronsted-Lowry base A substance capable of accepting protons. See proton. 

Bronsted-Lowry base A substance (molecule or ion) that acts as a proton acceptor. (Section 16.2) buffer capacity The amoimt of add or base a buffer can neutralize before the pH begins to change appredably. (Section 17.2)... 

Bronsted-Lowry base a substance that accepts a proton base de Bronsted-Lowry nna snstancia qne acepta nn proton... 

In the first reaction, the dihydrogen phosphate acts as a Bronsted-Lowry base, and in the second reaction, it acts as a Bronsted-Lowry acid. A substance that can act as either a Bronsted-Lowry acid or a Bronsted-Lowry base, depending on the circumstances, is called an amphoteric substance. 

An acid and a base always work together to transfer a proton. In other words, a substance can function as an acid only if another substance simultaneously behaves as a base. To be a Brcnsted-Lowry acid, a molecule or ion must have a hydrogen atom it can lose as an H ion. To be a Bronsted-Lowry base, a molecule or ion must have a non-bonding pair of electrons it can use to bind the H ion. 

A Bronsted-Lowry acid is a substance that donates a proton (H+), and a Bronsted-Lowry base is a substance that accepts a proton. (The name proton is often used as a synonym for hydrogen ion, H+, because loss of the valence electron from a neutral hydrogen atom leaves only the hydrogen nucleus— a proton.) When gaseous hydrogen chloride dissolves in water, for example, a polar HC1 molecule acts as an acid and donates a proton, while a water molecule acts as a base and accepts the proton, yielding hydronium ion (H30+) and chloride ion (Cl-). 

Bronsted-Lowry base (Section 2.7) A substance that accepts H+ from an acid. 

A base is a substance that can accept a proton. (Some chemists describe Bronsted-Lowry bases as proton-acceptors. )... 

Under the Bronsted-Lowry definition, an acid is a substance that donates a hydrogen ion (H+) in an acid-base reaction, while a base is a substance that accepts that hydrogen ion from the acid. When ionized to form a hydrogen cation, hydrogen loses its one and only electron and is left with only a single proton. For this reason, Bronsted-Lowry acids are often called proton donors, and Bronsted-Lowry bases are called proton acceptors. 

According to the Arrhenius theory, acids (HA) are substances that dissociate in water to produce H + (aq). Bases (MOH) are substances that dissociate to yield OH aq). The more general Bransted-Lowry theory defines an acid as a proton donor, a base as a proton acceptor, and an acid-base reaction as a proton-transfer reaction. Examples of Bronsted-Lowry acids are HC1, NH4+, and HSO4- examples of Bronsted-Lowry bases are OH-, F-, and NH3. 

The theory explains why a pure acid behaves differentiy from its aqueous solution, since for an acid to behave as an H+ ion donor it must have another substance present to accept the H+ ion. So the water, in the aqueous acid solution, is behaving as a Bronsted-Lowry base and accepting an H+ ion. Generally ... 

If a substance can behave both as a Bronsted-Lowry acid and as a Bronsted-Lowry base then it is called amphoteric. Water has this ability. As well as reacting with acids (above) it can also react with Bronsted-Lowry bases such as ammonia in the following way to form the base OH ... 

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). 

A Bronsted-Lowry base is a substance that accepts a proton from another substance. This is a significant change from the Arrhenius definition. Arrhenius bases possess an OH, whereas Bronsted-Lowry bases need not. In the example below, notice how ammonia increases the concentration of hydroxide ion in the resulting solution without donating a OH- ion. It does so by accepting a proton from water ... 

One very important thing to remember is that an acid and base are always present in these reactions. In order for a molecule or ion to donate a proton, there has to be another ion or molecule to receive it. In addition, in reversible acid-base reactions, the roles of the substances as proton donor or acceptor will switch in the reverse reaction. In the example below, note how water (a Bronsted-Lowry base in this reaction) accepts a proton to form a hydronium ion in the forward reaction. In the reverse reaction, the hydronium ion (Bronsted-Lowry acid) donates a proton and, after losing the proton, becomes the water molecule once again ... 

The idea of proton transfer has major implications for understanding the nature of acids and bases. According to the Bronsted-Lowry theory, any substance can behave as an acid, but only if another substance behaves as a base at the same time. Similarly, any substance can behave as a base, but only if another substance behaves as an acid at the same time. 

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. 

According to the Arrhenius concept, a base is a substance that produces OH-ions in aqueous solution. According to the Bronsted-Lowry definition, a base is a proton acceptor. The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) fulfill both criteria. They contain OH- ions in the solid lattice and behave as strong electrolytes, dissociating completely when dissolving in water ... 

A broader definition of acids and bases, which will be useful in quantitative calculations in this chapter, was proposed independently by Johannes Bronsted and Thomas Lowry in 1923. A Brensted-Lowry acid is defined as a substance that can donate a hydrogen ion, and a Bronsted-Lowry base is a substance that can accept a hydrogen ion. In a Bronsted-Lowry acid-base reaction, hydrogen ions are transferred from the acid to the base. When acetic acid is dissolved in water,... 

Some substances can act as a Bronsted-Lowry acid in one reaction and a Bronsted-Lowry base in another. Consider the following net ionic equations for the reaction of dihydrogen phosphate ion with either the acid hydrochloric acid or the strong base hydroxide. 

Amphoteric substance A substance that can act as either a Bronsted-Lowry acid or a Bronsted-Lowry base, depending on the circumstances. 

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. 

Zinc hydroxide is an amphoteric substance. Write equations that describe Zn(OH)2 acting as a Bronsted-Lowry base toward H and as a Lewis acid toward OH . 

Ammonia—a Bronsted-Lowry base All of the acids and bases that fit the Arrhenius definition of acids and bases also fit the Bronsted-Lowry definition. But some other substances that lack a hydroxide group and, therefore, cannot be considered bases according to the Arrhenius definition can be classified as acids according to the Bronsted-Lowry model. One example is ammonia (NHsj.When ammonia dissolves in water, water is a Bronsted-Lowry acid in the forward reaction. Because the NH3 molecule accepts a H+ ion to form the ammonium ion (NH4+), ammonia is a Bronsted-Lowry base in the forward reaction. 

Q A Bronsted-Lowry base is a substance that accepts an H ion from another species. 

In the forward reaction, HX donates a proton to H2O. Therefore, HX is the Bronsted-Lowry acid and H2O is the Bronsted-Lowry base. In the reverse reaction, the H3O ion donates a proton to the X ion, so H3O is the acid and X is the base. When the acid HX donates a proton, it leaves behind a substance, X , that can act as a base. Likewise, when H2O acts as a base, it generates H3O, which can act as an acid. 

For a substance to be a proton acceptor (a Bronsted—Lowry base), it must have an unshared pair of electrons for binding the proton, as, for example, in NH3. Using Lewis structures, we can write the reaction between and NH3 as... 

If a substance is an Arrhenius base, is it necessarily a Bronsted-Lowry base Is it necessarily a Lewis base Explain. 

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