What does copper matte contain?
1. Sulphides of copper(I), and iron(II)
2. Sulphides of copper (II), and iron(III)
3. Sulphides of copper(II), and iron(II)
4. Sulphides of copper(I), and iron(III)
Which of the following reactions is an example of autoreduction?
Which are the most abundant elements present inside the earth's crust?
1. Al, and Fe
2. Al, and Cu
3. Fe, and Cu
4. Cu, and Ag
Zone refining is based on the principle that-
1. | Impurities of low-boiling metals can be separated by distillation. |
2. | Impurities are more soluble in molten metal than in solid metal. |
3. | Different components of a mixture are differently adsorbed on an adsorbent. |
4. | Vapours of volatile compounds can be decomposed in pure metal. |
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of with :
1.
2.
3.
4.
Brine is electrolysed by using inert electrodes. The reaction at the anode is:
1. Cl-(aq) → \(\frac{1}{2}\)Cl2(g) + e-; \(E_{cell}^{o}\) = 1.36 V
2. 2H2O(l) → O2(g) + 4H+ + 4 e-; \(E_{cell}^{o}\) = 1.23 V
3. Na+(aq) + e- → Na(s); \(E_{cell}^{o}\) = 2.71 V
4. H+(aq) + e- → \(\frac{1}{2}\)H2(g); \(E_{cell}^{o}\) = 0.00 V
In the metallurgy of aluminium:
1. | Al3+ is oxidised to Al(s). |
2. | The graphite anode is oxidised to carbon monoxide and carbon dioxide. |
3. | Oxidation state of oxygen change in the reaction at the anode. |
4. | The oxidation state of oxygen changes in the overall reaction involved in the process. |
Which of the following metals can be purified by electrolytic refining?
1. Cu, and Zn
2. Ge, and Si
3. Zr, and Ti
4. Zn, and Hg
Extraction of gold and silver involves leaching the metal with ion. The metal is recovered by ......
1. | Displacement of metal by some other metal from the complex ion. |
2. | Roasting of metal complex. |
3. | Calcination followed byroasting. |
4. | Thermal decomposition of metal complex. |
The temperature at which carbon reduce FeO to Fe and produce CO is:
1. Lower than 400 oC
2. 400 oC
3. Higher than 600 oC
4. Higher than 400 oC