21. |
State the negative silicate ion in an aluminium mineral called kaolinite.
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Answer:
Option (a) |
22. |
Which of the following is not a method of concentration of ores ?
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Answer:
Option (b) |
23. |
Which depressant is added to the ore containing ZnS and PbS ?
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Answer:
Option (d) |
24. |
Mention the reaction representing example of leaching.
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Answer:
Option (c) |
25. |
When impure (native) silver is reacted with dilute aqueous solution of NaCN to form a water soluble complex, whose presence is necessary ?
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Answer:
Option (b) |
26. |
Before extracting metal from its sulphide ore, it is converted into its oxide. The ore is not reduced directly by carbon. Why ?
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Answer:
Option (c) |
27. |
What are the values of x and y for the reaction xCu2S(s) + yO2(g) → xCu2O(s) + xSO2(g) ?
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Answer:
Option (c) |
28. |
Use of electrolysis is not done in _____ .
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Answer:
Option (c) |
29. |
What is the value of ΔG° for oxidation-reduction reactions ?
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Answer:
Option (a) |
30. |
How is Gibbs-Helmholtz equation expressed ?
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Answer:
Option (c) |