Class 12 General Principles and Process of Isolation of Elements MCQs with Answer

Class 12 Chemistry General Principles and Process of Isolation of Elements MCQs with Answer

Q1. For the metallurgical process of which of the ores calcined ore can be reduced by carbon?

1. Haematite.
2. Calamine.
3. Iron pyrites.
4. Sphalerite.

Q2. Which of the following ores are concentrated by froth floation?

1. Haematite
2. Galena
3. Copper pyrites
4. Magnetite

Q6. Which of the following statements is correct about the role of substances added in the froth floation process?

1. Collectors enhance the non – wettability of the mineral particles.
2. Collectors enhance the wettability of gangue particles.
3. By using depressants in the process two sulphide ores can be separated.
4. Froth stabilisers decrease wettability of gangue.

Q8. When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte
contains __.

1. Sulphides of copper (II) and iron (II)
2. Sulphides of copper (II) and iron (III)
3. Sulphides of copper (I) and iron (II)
4. Sulphides of copper (I) and iron (III)

Q11. Extraction of gold and silver involves leaching the metal with CN^– 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 by roasting.
4. Thermal decomposition of metal complex.