Q. No.
The correct statement among the following is:
1.
Blister copper has a blistered appearance due to the evolution of CO2.
2.
Vapour phase refining is carried out for nickel by the Van Arkel method.
3.
Pig iron can be moulded into a variety of shapes.
4.
Wrought iron is impure iron with 4 % carbon.
Identify the incorrect statement:
| 1. | The scientific and technological process used for isolation of the metal from its ore is known as metallurgy |
| 2. | Minerals are naturally occurring chemical substances in the earth's crust |
| 3. | Ores are minerals that may contain a metal |
| 4. | Gangue is an ore contaminated with undesired materials |
The following reactions take place in the blast furnace in the preparation of impure iron.
Identify the reaction pertaining to the formation of the slag.
1. 2C(s) + O2(g) → 2CO (g)
2. Fe2O3(s) + 3CO (g) → 2Fe(l) + 3CO2(g)
3. CaCO3(s) → CaO(s) + CO2(g)
4. CaO(s) + SiO2(s) → CaSiO3(s)
The method of zone refining of metals is based on the principle of:
| 1. | Greater mobility of the pure metal than that of the impurity |
| 2. | Higher melting point of the impurity than that of the pure metal |
| 3. | Greater noble character of the solid metal than that of the impurity |
| 4. | Greater solubility of the impurity in the molten state than in the solid |
Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?
1. Distillation
2. Zone refining
3. Electrolysis
4. Chromatography
The maximum temperature that can be achieved in blast furnace is :
1. Upto 1900 K
2. Upto 5000 K
3. Upto 1200 K
4. Upto 2200 K
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
A pair of metals that can be purified by van Arkel method is:
1. Zr and Ti
2. Ag and Au
3. Ni and Fe
4. Ga and In
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