91Ó°ÊÓ

A certain buffer solution contains equal concentration of \(\mathrm{X}^{-}\)and \(\mathrm{HX}\). The \(\mathrm{Kp}\) for \(\mathrm{X}^{-}\)is \(10^{-10} .\) The \(\mathrm{pH}\) of the buffer is (a) 6 (b) 10 (c) 4 (d) 14

The precipitate of \(\mathrm{CaF}_{2}\left(\mathrm{Ksp}=1.7 \times 10^{-10}\right)\) is obtained when equal volumes of the following are mixed (a) \(10^{-2} \mathrm{M} \mathrm{Ca}^{2+}+10^{-3} \mathrm{MF}^{-}\) (b) \(10^{-3} \mathrm{M} \mathrm{Ca}^{2+}+10^{-5} \mathrm{MF}^{-}\) (c) \(10^{-4} \mathrm{M} \mathrm{Ca}^{2+}+10^{-4} \mathrm{MF}^{-}\) (d) \(10^{-5} \mathrm{M} \mathrm{Ca}^{2+}+10^{-3} \mathrm{MF}^{-}\)

The oxidation of \(\mathrm{SO}_{2}\) by \(\mathrm{O}_{2}\) to \(\mathrm{SO}_{3}\) is an exothermic reaction. They yield of \(\mathrm{SO}_{3}\) will be maximum if (a) temperature is reduced and pressure is increased (b) temperature is increased and pressure is kept constant (c) both temperature and pressure are reduced (d) both temperature and pressure are increased

Solution of \(0.1 \mathrm{~N} \mathrm{NH}_{4} \mathrm{OH}\) and \(0.1 \mathrm{~N} \mathrm{NH}_{4} \mathrm{Cl}\) has \(\mathrm{pH}\) 9.25, then find out \(\mathrm{pKb}\) of \(\mathrm{NH}_{4} \mathrm{OH}\) (a) \(9.25\) (b) \(4.75\) (c) \(3.75\) (d) \(8.25\)

Which has highest \(\mathrm{pH} ?\) (a) \(\mathrm{CH}_{3} \mathrm{COOK}\) (b) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (c) \(\mathrm{NH}_{4} \mathrm{Cl}\) (d) \(\mathrm{NaNO}_{3}\)

The hydrogen ion concentration of a \(10^{-8} \mathrm{M} \mathrm{HCl}\) aqueous solution at \(298 \mathrm{~K}\left(\mathrm{Kw}=10^{-14}\right)\) is (a) \(9.525 \times 10^{-8} \mathrm{M}\) (b) \(1.0 \times 10^{-8} \mathrm{M}\) (c) \(1.0 \times 10^{-6} \mathrm{M}\) (d) \(1.0525 \times 10^{-7} \mathrm{M}\)

Solubility of a \(\mathrm{M}_{2} \mathrm{~S}\) salt is \(3.5 \times 10^{-6}\) then find out solubility product. (a) \(1.7 \times 10^{-6}\) (b) \(1.7 \times 10^{-16}\) (c) \(1.7 \times 10^{-18}\) (d) \(1.7 \times 10^{-12}\)

Solubility of \(\mathrm{MX}_{2}\) type electrolyte is \(0.5 \times 10^{-4} \mathrm{~mol}\) \(\mathrm{L}^{-1}\). Then find out Ksp of electrolytes. (a) \(5 \times 10^{-12}\) (b) \(25 \times 10^{-10}\) (c) \(1 \times 10^{-13}\) (d) \(5 \times 10^{-13}\)

The solubility product of a sparingly soluble salt \(\mathrm{AX}_{2}\) is \(3.2 \times 10^{-11} .\) Its solubility (in \(\mathrm{mol} \mathrm{L}^{-1}\) ) is (a) \(5.6 \times 10^{-6}\) (b) \(3.1 \times 10^{-4}\) (c) \(2 \times 10^{-4}\) (d) \(4 \times 10^{-4}\)

pKa value of four acids are given below. The strongest acid is (I) \(4.0\) (II) \(3.5\) (III) \(2.5\) (IV) 2 (a) I (b) II (c) III (d) IV