Question

For solutions of the same concentration, as acid strength increases, indicate what happens to each of the following (increases, decreases, or doesn’t change).

$\begin{array}{l}\mathbf{a}.\left[{\mathbf{H}}^{+}\right]\\ \mathbf{b}.\mathbf{pH}\\ \mathbf{c}.\left[{\mathbf{OH}}^{-}\right]\\ \mathbf{d}.\mathbf{pOH}\\ \mathbf{e}.{\mathbf{K}}_a\end{array}$

Short answer

On increasing acidic strength, [H⁺] ion concentration increases, the value of pH decreases, [OH^-] ion concentration decreases, the value of pOH increases, and the value of dissociation constant (K_a) also increases.

Step-by-step solution

Effect of [H+] ion concentration on acidic strength

[H⁺] ion concentration increases as the dissociation of acid increases, which means with an increase in acidic strength, [H⁺] ion concentration increases.

Effect of acidic strength on pH

As acidic strength [H⁺] ion concentration increases, pH decreases.

As $\mathbf{pH}\mathbf{=}\mathbf{-}\mathbf{log}\mathbf{[}{\mathbf{H}}^{+}\mathbf{]}$

Effect of Acidic Strength on [OH-] ion Concentration

With the increase in acidic strength,$\left[{\mathrm{H}}^{+}\right]$ion concentration increases; thus, [OH^-] concentration decreases.

${\text{[H}}^{\text{+}}\text{]=}\frac{{\mathrm{K}}_{\mathrm{w}}}{\left[{\text{OH}}^{\text{-}}\right]}$

Effect of Acidic Strength on [OH-] ion Concentration

With the increase in acidic strength, [H⁺] ion concentration increases, pH decreases, and pOH increases.

${\text{[H}}^{\text{+}}\text{]}\uparrow \text{es},\text{\hspace{0.17em}pH\hspace{0.17em}}\downarrow \text{es,pOH}\uparrow \text{es}$

Effect of Acidic Strength on Ka

Acidic strength increases with an increase in the dissociation of an acid. The more the dissociation, the more the value of the dissociation constant will be. Thus, the Ka value increases with increasing acidic strength.