Question

Consider oxoacids of $N , S$ and $Cl$.
(I) $HNO _{2}, HNO _{3}, H _{2} N _{2} O _{2}$
(II) $H _{2} SO _{3}, H _{2} SO _{4}, H _{2} S _{2} O _{3}$
(III) $HCIO , HCIO _{2}, HCIO _{3}, HCIO _{4}$
Strongest acid in each case is

	(I)	(II)	(III)
(a)	$HNO_3$	$H_2SO_4$	$HClO_4$
(b)	$H_2N_2O_2$	$H_2S_2O_3$	$HClO$
(c)	$HNO_3$	$H_2SO_3$	$HClO_3$
(d)	$HNO_3$	$H_2SO_3$	$HClO_3$

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (A)

Greater the oxidation number of the central atom, stronger is the acid

(I) $\underset{+3}{HNO_2} \, \underset{+5}{HNO_{3}}\, \underset{+1}{H_2N_2O_{2}}$

(II) $\underset{+4}{H_2 SO_{3}}\, \underset{+6}{H_2 SO_{4}}\, \underset{+2}{H_2S_2O_{3}}$

(III) $\underset{+1}{HCl}\, \underset{+3}{HClO_{2}}\, \underset{+5}{HClO_{3}}\, \underset{+7}{HClO_{4}}$

In $(I) : HNO _{3}( II ): H _{2} SO _{4}( III ): HClO _{4}$