The better reducing agent for ZnO is:
1. C
2. CO
3. CO2
4.
The process in which Cl2 is obtained as a by-product is :
1. | In the electrolysis of aqueous HCl, Cl2 is obtained at the cathode as a by-product. |
2. | In the electrolysis of aqueous NaCl, Cl2 is obtained at the cathode as a by-product. |
3. | In the electrolysis of molten NaCl, Cl2 is obtained at the anode as a by-product. |
4. | None of the above |
Al can reduce MgO under the following conditions:
1. Above 500 °C, Al can reduce MgO
2. Below 500 °C, Al can reduce MgO
3. Below 1350 °C, Al can reduce MgO
4. Above 1350 °C, Al can reduce MgO
Consider the following statements:
a. | Zone refining method is useful for producing semiconductors and other metals of very high purity. |
b. | Zone refining method is based on the principle that "the impurities are less soluble in the melt than in the solid-state of the metal". |
c. |
In column chromatography, the most readily adsorbed substances are retained near the top. |
d. | In column chromatography, the stationary phase is packed in a glass tube. |
Select the correct statements.
1. a, c, d
2. a, b
3. b, c
4. a, b, c, d
The chemical reactions taking place in the extraction of zinc from zinc blende is
1.
2.
3. Both 1 and 2
4. None of the above
The reaction that do not take place in the blast furnace during the extraction of iron is-
1. Fe2O3(s) + 3CO(g) → 2Fe3O4(s) + 3CO2(g)
2. FeO(s) + CO(g) → Fe(s) + CO2(g)
3. 2 C(s) + O2(g) → 2 CO(g)
4. None of the above
Incorrect statement(s) among the following options is/are:
1. | Roasting is done in a limited supply of air. |
2. | Calcination is done in the absence, or a limited supply of air. |
3. | Roasting is done in a regular supply of air. |
4. | All of the above. |
The thermodynamic property useful for selecting the reducing agent is:
1. Gibbs free energy change .
2. Internal energy change.
3. Specific heat capacity.
4. None of the above.
Vapour phase refining process is used for refining :
1. Ni
2. Ti
3. Zr
4. All of the above
The incorrect statement(s)among the following is/are:
1. | Zone refining is based on the principle that impurities are more soluble in the molten state of metal (the melt) than in the solid-state. |
2. | Electrolytic refining is the process of refining impure metals by using electricity. |
3. | The impurities present in the impure metal gets collected below the anode in the electrolytic refining process. |
4. | None of the above |