Chemistry – Class 12 Mock Test 3

10%

Question 1 of 10

1. What is the main reaction occurring in the blast furnace during extraction of iron from haematite?

Fe₂O₃ + 3CO → 2Fe + 3CO₂

FeO + SiO₂ → FeSiO₂

Fe₂O₃ + CO₂ → FeCO₃ + O₂

Fe₂O₃ + 3C → 2Fe + 3CO

Question 1 of 10

Question 2 of 10

2. A finely divided substance is more effective as an adsorbent.

True

False

Question 2 of 10

Question 3 of 10

3. What is the name of the alloy of copper called which contains a composition of 30-35% of zinc?

Bronze

Duralumin

Magnalium

Brass

Question 3 of 10

Question 4 of 10

4. Which of the following processes involves the dissolution of the ore in a suitable reagent followed by precipitation of the metal by a more reactive metal?

Smelting

Hydrometallurgy

Froth floatation

Casting

Question 4 of 10

Question 5 of 10

5. Which of the following can be used in place of tannin for the process of tanning?

Zinc salts

Chromium salts

Copper salts

Cobalt salts

Question 5 of 10

Question 6 of 10

6. Which of the following is not an impurity generally present in crude metals?

Pine oil

Other metals

Non-metals

Unreacted oxides

Question 6 of 10

Question 7 of 10

7. Colloids are classified into multi-molecular, macro-molecular and associated colloids.

True

False

Question 7 of 10

Question 8 of 10

8. Which of the following ions is the brown ring test useful for determining?

NO₂

NO₂⁺

NO₂^-

NO₃^-

Question 8 of 10

Question 9 of 10

9. In the Haber-Bosch process, what is formed by the reaction of natural gas and steam?

Oxygen

Hydrogen

Ammonia

Nitrogen

Question 9 of 10

Question 10 of 10

10. Silver is extracted from which of the following ore?

Calamine

Cinnabar

Malachite

Argentite

Question 10 of 10