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The Bronsted-Lowry hypothesis is indeed an acid-base reaction theory, first proposed in 1923 by Danish chemists Johannes Nicolaus Bronsted and Thomas Martin Lowry. According to the hypothesis, acid and base interact with one another, with the acid-forming its conjugate base and also the base forming its conjugate acid through proton interchange.
The Bronsted-Lowry hypothesis is a more advanced variant of the Arrhenius acid-base theory. Acid raises the concentration of Hydrogen ions in an aqueous solution, whereas base raises the percentage of OH– ions, as per the Arrhenius hypothesis. The Arrhenius theory has a restriction in that it only detects the interaction of an acid and a base during an aqueous phase.
Bronsted-Lowry Theory
About the Hypothesis According to the Bronsted Lowry method, a constituent only acts as an acid in the presence of such a base, but only acts as a base within the absence of an acid. Moreover, once an acidic substance loses one proton, it creates an acidic solution known also as an acid conjugate base, and when a basic substance obtains a proton, it produces the acid known as base conjugate acid. As just a result, the reaction with an acidic chemical like hydrochloric acid and a basic substance like ammonia can be best summed up:
HCl +NH3⇌NH4++Cl–
The ammonium ion (NH+4) is indeed the acid correspondent of the basic ammonia, while the chloride ion (Cl-) is indeed the base correspondent of hydrochloric acid there in the formula above.
The Bronsted–Lowry hypothesis further broadens the definition of acids and bases to also include not just neutral molecules (such as alkali metal hydroxides and nitric, sulphuric, and acetic acids), and also atoms and molecules with opposite electrical charges (called cations and anions). Acids include hydroxide ions, ammonium ions, and various saturated metal cations. Bases include phosphorus, acetate, sulphide, carbonate, and halogen ions.
Bronsted-Lowry bases
These must have the ability to accept H+ ions into their framework.
When sulphuric acid & nitric acid combine, the sulphuric acid transfers a proton to one of the nitric acid’s oxygens. It’s the initial step in the nitronium ion’s creation, NO2+.
Sulphuric acid acts as a Bronsted-Lowry acid in just this reaction, whereas nitric acid acts as a Bronsted-Lowry base.
H2SO4 + HNO3 → [H2NO3]+ + HSO4–
[H2NO3]+ →H2O + NO2+
Weak and Strong bases
A strong base would ionise in an aqueous medium. Sodium hydroxide, or NaOH, is a sign of a good base. Sodium hydroxide fully dissolved in water, yielding sodium and hydroxide ions:
NaOH(aq)→Na + (aq)+OH − (aq)
As a result, when we form a solution of sodium hydroxide with water, we only get Na and OH ions in the end. We do not even anticipate any NaOH to be undissociated.
Try looking at ammonia now. Because ammonia is indeed a weak base, it will ionise partly in water:
NH3 (aq) + H2O(l) ⇌ NH4 + (aq)+OH − (aq)
Ammonium ions & hydroxide ions are formed when certain ammonia molecules absorb a proton in water. Ammonia molecules constantly exchange protons for water, while ammonium ions constantly donate protons again to hydroxide, resulting in a dynamic equilibrium. Since ammonia will just deprotonate waters to a minimal amount, the main species under solution is non-ionized ammonia.
Key Points
A Bronsted-Lowry acid is a type of chemical that can donate a proton or a hydrocarbon cation.
A Bronsted-Lowry base is a type of chemical that can receive a proton. In many other words, it was a species with a single electron pair that can attach to H+.
After donating a proton, a Bronsted-Lowry acid creates its conjugate base. When a Brønsted-Lowry base receives a proton, it generates the conjugate acid. The chemical formula of the conjugate acid-base pair is identical to that of the initial acid-base pair, with the exception that the acid has one more H+ than the conjugate base.
Compounds that ionize in water are known as strong acids and bases. Weak acids and bases typically dissolve partly.
Aqua is amphoteric, as per this hypothesis, and may operate as both a Bronsted-Lowry acid and a Brønsted-Lowry base.
Conclusion
In 1923, Danish chemists Johannes Nicolaus Bronsted & Thomas Martin Lowry devised the Bronsted-Lowry concept, which is an acid-base reactions concept. As well as, per the theory, acid and base react by proton exchange, with acid creating its conjugate base as well as the base producing its conjugate acid.
Bronsted Lowry bases have to be able to take in H+ ions in their structure.
Once sulphuric acid and nitric acid merge, the sulphuric acid donates a proton to one of the oxygens within nitric acid. NO2+ is the first stage in the formation of the nitronium ion. Throughout this reaction, sulphuric acid functions like a Bronsted-Lowry acid, while nitric acid works like a Bronsted-Lowry base.
