259) The hydrogen ion concentration of 0.06M benzoic acid solution will be: (K_a = 6 x 10⁻³)

260) A beaker contains 1 L of 0.1M acetic acid solution. To neutralize the acid partially, 1 gm of NaOH has been added. If the pK_a of acetic acid is 4.75, then the pH of the partially neutralized acetic acid solution will be:

261) Mass of H₂C₂O₄ required to reduce 100 mL of 0.008M KMnO₄ in acidix medium is x gm and to neutralize 100 mL of 0.01M Mg(OH)₂ is y gm, then the relation between x and y is:

262) The pH of 0.1M solution of the following, increases in the order:

263) What is [H⁺] in mol⁄L of a solution that is 0.2M in CH₃COONa and 0.1M in CH₃COOH? K_a for CH₃COOH = 1.8 x 10⁻⁵