MCQ
Peroxo acids of sulphur are
- A$H_2SO_5, \,H_2SO_3$ and $H_2S_2O_8$
- B$H_2SO_4, \,H_2S_2O_8$ and $H_2SO_3$
- C$H_2S_2O_7, \,H_2SO_3$ and $H_2SO_4$
- ✓$H_2S_2O_8$ and $H_2SO_5$
$S ^{2-}$ will give $H _{2} S ( g )$, will turns lead acetate paper black.
$SO _{3}{ }^{2-}$ will give $SO _{2}( g )$, which will turns acidified potassium dichromate solution green.
$NO _{2}^{-}$will give brown $NO _{2}( g )$ will turn $KI$ solution blue.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.


$HC \equiv CH\mathop {\xrightarrow{{NaN{H_2},C{H_3}COC{H_3}}}}\limits_{{H^ + }} X\mathop {\xrightarrow{{H{g^{2 + }},{H_3}{O^ + }}}}\limits_{{H_2}O} Z$ is
$4M + 8CN^-+ 2H_2O + O_2 \rightarrow 4[M(CN)_2]^-+ 4OH^-$
$2[M(CN)_2]^-+ Zn \rightarrow [Zn(CN)_4]^{2-} + 2M$
| Element | Ionization | enthalpy | $(kJ/mol)$ |
| $1^{st}$ | $2^{nd}$ | $3^{rd}$ | |
| $A$ | $899$ | $1757$ | $14847$ |
| $B$ | $737$ | $1450$ | $7731$ |
Which of the following statements is correct ?