Problem 152
In which of the following pair (s), the minerals are converted into metals by self reduction ? (a) \(\mathrm{Cu}_{2} \mathrm{~S}, \mathrm{HgS}\) (b) \(\mathrm{Ag}_{2} \mathrm{~S}, \mathrm{ZnS}\) (c) \(\mathrm{PbS}, \mathrm{ZnS}\) (d) \(\mathrm{Cu}, \mathrm{S}, \mathrm{PbS}\)
Problem 154
The following methods are not advisable to extract zinc from its oxide ore. (a) Reduction with aluminium (b) Reduction with \(\mathrm{H}_{2}\) (c) Electrolytic reduction (d) Reduction with carbon
Problem 155
In the process of extraction of gold Roasted gold ore \(+\mathrm{CN}^{-}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{O}_{2}}{\longrightarrow}[\mathrm{X}]+\mathrm{OH}^{-}\) \([\mathrm{X}]+\mathrm{Zn} \longrightarrow[\mathrm{Y}]+\mathrm{Au}\) Identify the complexes of \([\mathrm{X}]\) and \([\mathrm{Y}]\) (a) \(\mathrm{Y}=\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{2-}\) (b) \(\mathrm{X}=\left[\mathrm{Au}(\mathrm{CN})_{4}\right]^{3-}\) (c) \(\mathrm{X}=\left[\mathrm{Au}(\mathrm{CN})_{2}\right]\) (d) \(\mathrm{Y}=\left[\mathrm{Zn}(\mathrm{CN})_{6}\right]^{4-}\)
Problem 156
The method of thermal decomposition cannot be used for (a) \(\mathrm{Au}\) (b) \(\mathrm{Hg}\) (c) \(\mathrm{Mg}\)
Problem 160
Match the following \begin{tabular}{ll} \hline Column-I & Column-II \\ \hline (a) Asbestos & (p) Calcium \\ (b) Willemite & (q) Lead \\ (c) Anglesite & (r) Silicate \\ (d) Diaspore & (s) Aluminium \\ & (t) Sulphate \\ \hline \end{tabular}
Problem 161
The number of sulphide minerals of the following is Cuprite, Argentite, Carnallite, Magnesite, Galena, Black Jack.
Problem 162
Among the metals, Ti, V, W, Zr, Th and Au, the no. of metals purified by van Arkel method is
Problem 163
\text { Among the following minerals, siderite, malachite, }cerussite, anglessite, smithsonite, diaspore, mica and corundum, the number of carbonate minerals is
Problem 166
When the sample of copper with zinc impurity is to be purified by electrolysis the appropriate electrodes are [2002] Cathode \(\quad\) Anode (a) pure zinc \(\quad\) pure copper (b) pure copper impure sample (c) impure zinc impure sample (d) impure sample pure copper
Problem 168
Which one of the following nitrates will leave behind a metal on strong heating? [2003] (a) ferric nitrate (b) copper nitrate (c) manganese nitrate (d) silver nitrate
