For a weak monobasic acid $\mathrm{HA}$ of concentration $0.1\mathrm{M}$ and $K_a=10^{-5}$, the pH (using $[\mathrm{H}{}^{+}]=\sqrt{K_{a}c}$) is

More questions on pH of strong and weak acids and bases, mixtures

• The pH of a 0.01 M solution of HCl at 298 K is NEET level
• The pH of a 0.001 M solution of NaOH at 298 K is NEET level
• The pH of a 5x10^-4 M solution of Ba(OH)2 at 298 K (assume complete ionisation) is NEET level
• The pH of a 0.005 M solution of H2SO4 at 298 K, assuming complete ionisation of both protons, is NEET level
• The degree of ionisation of 0.1 M acetic acid (K_a=1.8x10^-5) is nearest to (use alpha=sqrtK_a/c) NEET level
• A 0.1 M solution of a weak monobasic acid has pH 3.0. Treating ionisation as small compared with c, its pK_a is NEET level