Embibe Experts Solutions for Chapter: Redox Reactions, Exercise 1: TS EAMCET 2018 (04-May Shift-1)

From the given reactions identify the disproportionation reaction
i) ${\mathrm{Cl}}_2\left(\mathrm{g}\right)+2\mathrm{KI}\left(\mathrm{aq}\right)⟶2\mathrm{KCl}\left(\mathrm{aq}\right)+{\mathrm{I}}_2\left(\mathrm{s}\right)$
ii) ${\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)⟶{\mathrm{ClO}}^{-}\left(\mathrm{aq}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
iii) $\mathrm{Mg}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)⟶{\mathrm{MgCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$
iv) $2{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{aq}\right)⟶2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

In the balanced equation of the following reaction, the ratio of $\mathrm{a}/\mathrm{b}$ is 

 ${\mathrm{aCaCO}}_3+{\mathrm{bH}}_3{\mathrm{PO}}_4\to {\mathrm{pCa}}_3{\left({\mathrm{PO}}_4\right)}_2+{\mathrm{qCO}}_2+{\mathrm{rH}}_2\mathrm{O}$

${\mathrm{KMnO}}_4$ oxidises oxalic acid in acidic medium. The number of ${\mathrm{CO}}_2$ molecules produced per mole of ${\mathrm{KMnO}}_4$ is

In the titration of ${\mathrm{I}}_2 \left(\mathrm{aq}\right)$ by ${\mathrm{S}}_2{\mathrm{O}}_3^{2-}$ $\left(\mathrm{aq}\right)$ using the starch indicator, the end point is indicated by: