Which one is a malachite from the following?
1. CuCO3.Cu(OH)2
2. CuFeS2
3. Cu(OH)2
4. Fe3O4
Sulphide ores of metals are usually concentrated by the froth flotation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?
1. Argentite
2. Galena
3. Copper pyrite
4. Sphalerite
Which of the following elements is present as an impurity to the maximum extent in the pig Iron?
1. Carbon
2. Silicon
3. Phosphorus
4. Manganese
An interstitial compound among the following is:
1. Invar
2. Steel
3. Bell metal
4. Bronze
Which one of the following is a mineral of iron?
1. Malachite
2. Cassiterite
3. Pyrolusite
4. Magnetite
Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with a choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic and acts as an oxidizing agent and its acid has never been isolated. The gas X is:
1. SO2
2. CO2
3. SO3
4. H2S
"Metals are usually not found as nitrates in their ores". Out of the following two (I and II) reasons which is/are true for the above observation?
I: | Metal nitrates are highly unstable. |
II: | Metal nitrates are highly soluble in water. |
Considering Ellingham diagram, which of the following metals can be used to reduce alumina?
1. Fe
2. Zn
3. Mg
4. Cu
The correct statement among the following is:
1. | The rate of reaction cannot be understood from the Ellingham diagram. |
2. | During the formation of metal oxide becomes negative and becomes positive resulting in a positive slope. |
3. | There is an abrupt change in the slope of the Ellingham line when a change in phase (s→l) or (l→g) takes place. |
4. | All of the above. |
The processes (ii) and (i) above, respectively, are :
1. Mond's process; Van Arkel process
2. Van Arkel process; Mond's process
3. Goldschmidt process; Mond's process
4. Mond's process; Goldschmidt process