Question

What is the Bronsted-Lowry definition of a base? a compound that donates protons a compound that accepts protons a substance that increases hydroxide ion concentration a substance that increases hydronium ion concentration

Answer 1

According to Bronsted-Lowry concept, a compound which donates proton is said to be an acid and a compound which accepts proton is said to be base.

Strong bases and acids are completely ionised in aqueous solution whereas weak bases and weak acids ionise partially. The conjugate base is defined as the species which is formed after the loss of proton from an acid and conjugate acid is the species which is formed after the gain of protons.

Hence, Bronsted-Lowry definition of a base is a compound which accepts proton.

Answer 2

The Bronsted-Lowry base is $\boxed{{\text{a compound that accepts protons}}}$

Further Explanation:

Acids and bases can be defined in many ways based on different theories, which are as follows:

1. Arrhenius theory: According to this theory, acid is defined as the one which produces hydrogen or hydronium ions in a solution, while the base is defined as the one which produces hydroxide ions in a solution. Examples of Arrhenius acids include HBr, ${\text{HN}}{{\text{O}}_3}$ and ${{\text{H}}_2}{\text{S}}{{\text{O}}_4}$ while NaOH and KOH are examples of Arrhenius bases.

2. Bronsted-Lowry theory: According to this theory, the acid in the reaction donates a proton while a base is one that accepts a proton. ${{\text{H}}_2}{\text{O}}$ acts as Bronsted acid while ${\text{N}}{{\text{H}}_3}$ is a Bronsted base.

Ammonia is an example of a Bronsted-Lowry base as it accepts protons from the other species like water. Water, therefore, acts as Bronsted-Lowry acid as it donates a proton to other species. (Refer to the attached image)

3. Lewis theory: According to this theory, an acid accepts a pair of electrons to electron-rich species while a base donates electrons to electron-deficient species in the reaction. Examples of Lewis acids are ${\text{B}}{{\text{F}}_3}$ , ${\text{S}}{{\text{O}}_3}$ while ${{\text{H}}_2}{\text{O}}$ and ROH are the examples of Lewis base.

(A) According to Bronsted-Lowry theory, the compound that donates protons is known as acid, not base. So this statement is incorrect.

(B) According to Bronsted-Lowry theory, the compound that accepts protons is known as base. So this statement is correct.

(C) A compound that increases hydroxide ion concentration is a base but according to Arrhenius theory and not Bronsted-Lowry theory. So it is not a Bronsted-Lowry base and therefore this statement is incorrect.

(D) A compound that increases hydronium ion concentration is an acid but according to Arrhenius theory and not Bronsted-Lowry theory. So it is not a Bronsted-Lowry base and therefore this statement is incorrect.

Learn more:

1. The reason for the acidity of water brainly.com/question/1550328

2. Reason for the acidic and basic nature of amino acid. brainly.com/question/5050077

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Acid, base and salts

Keywords: acid, base, electrons, protons, Arrhenius theory, Lewis theory, Bronsted-Lowry theory, hydrogen, hydronium ion, hydroxide ion, accept, donate.