91Ó°ÊÓ

Hydroxylamine reduces iron (III) according to the equation: \(2 \mathrm{NH}_{2} \mathrm{OH}+4 \mathrm{Fe}^{3+} \rightarrow \mathrm{N}_{2} \mathrm{O}(\mathrm{g}) \uparrow+\mathrm{H}_{2} \mathrm{O}+4 \mathrm{Fe}^{2+}+4 \mathrm{H}^{+}\) Iron (II) thus produced is estimated by titration with a standard permanganate solution. The reaction is : $$ \mathrm{MnO}_{4}^{-}+5 \mathrm{Fe}^{2+}+8 \mathrm{H}^{+} \rightarrow \mathrm{Mn}^{2+}+5 \mathrm{Fe}^{3+}+4 \mathrm{H}_{2} \mathrm{O} $$ A \(10 \mathrm{~mL}\). sample of hydroxylamine solution was diluted to 1 litre. \(50 \mathrm{~mL}\). of this diluted solution was boiled with an excess of iron (III) solution. The resulting solution required \(12 \mathrm{~mL}\). of \(0.02 \mathrm{M} \mathrm{KMnO}_{4}\) solution for complete oxidation of iron (II). Calculate the weight of hydroxylamine in one litre of the original solution. \((\mathrm{H}=1, \mathrm{~N}=14, \mathrm{O}\) \(=16, \mathrm{~K}=39, \mathrm{Mn}=55, \mathrm{Fe}=56)\) [1982 - 4 Marks]

What weight of \(\mathrm{AgCl}\) will be precipitated when a solution containing \(4.77 \mathrm{~g}\) of \(\mathrm{NaCl}\) is added to a solution of \(5.77 \mathrm{~g}\) of \(\mathrm{AgNO}_{3} ?\) [1978]

A solid mixture \((5.0 \mathrm{~g})\) consisting of lead nitrate and sodium nitrate was heated below \(600^{\circ} \mathrm{C}\) until the weight of the residue was constant. If the loss in weight is \(28.0\) per cent, find the amount of lead nitrate and sodium nitrate in the mixture. [1990-4 Marks]