91Ó°ÊÓ

The ionization constant of nitrous acid is \(4.5 \times 10^{-4} .\) Calculate the pH of \(0.04 \mathrm{M}\) sodium nitrite solution and also its degree of hydrolysis.

A \(0.02 \mathrm{M}\) solution of pyridinium hydrochloride has \(\mathrm{pH}=3.44\). Calculate the Ionization constant of pyridine.

Predict if the solutions of the following salts are neutral, acidic or basic: \(\mathrm{NaCl}, \mathrm{KBr}, \mathrm{NaCN}, \mathrm{NH}_{4} \mathrm{NO}_{3}, \mathrm{NaNO}_{2}\) and \(\mathrm{KF}\)

Ionic product of water at \(310 \mathrm{~K}\) is \(2.7 \times 10^{-14}\). What is the pH of neutral water at this temperature?

Calculate the \(\mathrm{pH}\) of the resultant mixtures: a) \(10 \mathrm{~mL}\) of \(0.2 \mathrm{M} \mathrm{Ca}[\mathrm{OH})_{2}+25 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{HCl}\) b) \(10 \mathrm{~mL}\) of \(0.01 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}+10 \mathrm{~mL}\) of \(0.01 \mathrm{M} \mathrm{Ca}(\mathrm{OH})_{2}\) c) \(10 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}+10 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{KOH}\)

Equal volumes of \(0.002 \mathrm{M}\) solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper lodate? (For cupric lodate \(K_{\text {cp }}=7.4 \times 10^{8}\) ).

The ionization constant of benzoic acid is \(6.46 \times 10^{5}\) and \(K_{\text {sp }}\) for silver benzoate is \(2.5 \times 10^{-13}\). How many times is silver benzoate more soluble in a buffer of \(\mathrm{pH}\) \(3.19\) compared to its solubility in pure water?

The concentration of sulphide ion in \(0.1 \mathrm{M} \mathrm{HCl}\) solution saturated with hydrogen sulphide is \(1.0 \times 10^{19} \mathrm{M}\). If \(10 \mathrm{~mL}\) of this is added to \(5 \mathrm{~mL}\) of \(0.04 \mathrm{M}\) solution of the following: \(\mathrm{FeSO}_{4}, \mathrm{MnCl}_{2}, \mathrm{ZnCl}_{2}\) and \(\mathrm{CdCl}_{2}\). in which of these solutions precipitation will take place?