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JEE Mains | PYQ

\(0.01\,\text{M}\) KMnO\(_4\) solution was added to \(20.0\,\text{mL}\) of \(0.05\,\text{M}\) Mohr's salt solution through a burette. The initial reading of \(50\,\text{mL}\) burette is zero. The volume of KMnO\(_4\) solution left in the burette after the end point is ______ \( \text{mL} \). (nearest integer)

Which one of the following is an example of disproportionation reaction?

The disproportionation of \( \mathrm{MnO_4^{2-}} \) in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment \( (\mu) \) value of B in \( \text{BM} \) is _______. (Nearest integer)

\( 20 \, \text{mL} \) of \( 0.02 \, \text{M} \) hypo solution is used for the titration of \( 10 \, \text{mL} \) of copper sulphate solution, in the presence of excess of \( \mathrm{KI} \) using starch as an indicator. The molarity of \( \mathrm{Cu^{2+}} \) is found to be be _______ \( \times 10^{-2} \, \text{M} \). (nearest integer)
Given : \( 2\mathrm{Cu^{2+}} + 4\mathrm{I^-} \rightarrow \mathrm{Cu_2I_2} + \mathrm{I_2} \) 
\( \mathrm{I_2} + 2\mathrm{S_2O_3^{2-}} \rightarrow 2\mathrm{I^-} + \mathrm{S_2O_6^{2-}} \)

A \( 2.0 \, \text{g} \) sample containing \( \mathrm{MnO_2} \) is treated with \( \mathrm{HCl} \) liberating \( \mathrm{Cl_2} \). The \( \mathrm{Cl_2} \) gas is passed into a solution of \( \mathrm{KI} \) and \( 60.0 \, \text{mL} \) of \( 0.1 \, \text{M} \) \( \mathrm{Na_2S_2O_3} \) is required to titrate the liberated iodine. The percentage of \( \mathrm{MnO_2} \) in the sample is ______ (nearest integer) [Atomic masses (in \( \text{u} \)) \( \mathrm{Mn} = 55 \); \( \mathrm{Cl} = 35.5 \); \( \mathrm{O} = 16 \), \( \mathrm{I} = 127 \), \( \mathrm{Na} = 23 \), \( \mathrm{K} = 39 \), \( \mathrm{S} = 32 \)]

In neutral or alkaline solution, \( \mathrm{MnO}_4^{-} \) oxidises thiosulphate to: