Chapter 4, Problem 45CTQ

Interpretation Introduction

Interpretation: Letter (a to e) that best completes new definition of strong base in order to be consistent with old definition of strong base should be determined.

Concept introduction: According to Bronsted-Lowry concept, substance that donates proton is termed as acid while that accepts or gains protons is called base. Species formed after loss of protons from acids are known as their respective conjugate bases whereas conjugate acid is produced by addition of protons to base. Strength of conjugate acids and conjugate bases are inversely related to strengths of their respective bases and acids.

According to Lewis concept, substance that donates electron pair is termed as base while that accepts or gains electron pair is called acid. For example, ${\text{BF}}_{\text{3}}$ is electron-deficient compound and can easily accept electrons so it is Lewis acid. But ${\text{NH}}_{\text{3}}$ has lone pair of electrons that it can donate easily so it acts as Lewis base.

According to Arrhenius concept, substances that donate hydrogen ions in solutions are known as acids while bases are substances that release hydroxide ions in solutions.