NEET Chemistry Solved Question Paper 2001

Concentration NH₄OH solution = 0.1 N

Concentration of OH ions in solution, 

$\left[{\mathrm{OH}}^{-}\right] = 20\% \mathrm{of} 0.1\mathrm{N} =\frac{20}{100}\times 0.1$

$$\begin{gathered} \mathrm{pOH} = -\log \left[{\mathrm{OH}}^{-}\right] = -\log (0.02) \\ = 2- 0.301 \\ \mathrm{pH} = 14-\mathrm{pOH} = 12.30 \end{gathered}$$

HClO₄ is the strongest acid among HClO, HClO_2, HClO_3, and HClO₄ as more the number of oxygen atoms attached, more is the acidity of the molecule order of acidity is :

HClO < HClO₂ < HClO₃ < HClO₄

So the conjugate base order will be just reverse:

ClO^- > ClO₂^- > ClO₃^- > ClO₄^-