Question

On what factors does the strength of an acid depends ?

Answer 1

The strength of an acid refers to its ability or tendency to lose a proton (H⁺).
The strength of an acid, in comparison to other acids, depends on several characteristics: Electronegativity: The higher the electronegativity of a conjugate base in the same period, the more acidic.

Factors Affecting Acid Strength

• It depends on the strength of the H-A bond. The weaker the bond, the lesser the energy required to break it. Hence, the acid is strong.
• The polarity of the H-A bond affects its acid strength. If the bond is highly polar, the proton tends to leave the molecule more easily, making it a strong acid.
• However, bond strength is more important when we consider and compare acid strengths of elements in the same group of the periodic table, using the above two factors.
• Nevertheless, when we compare the acid strengths of elements in the same row, priority is given to the polarity of the H-A bond.
• The atomic size of A also affects the acid strength. As the atom becomes larger, the bond gets weaker. Consequently, acid strength increases.