Page 3 - 3. Home Assignment - Ch-3 Concept mapping

5. What kind of compounds are called ionic compounds.

D] Metallurgy:

1. In nature, aluminium is found in combined state silver/gold are found
in free state. Give reason.

2.
The reaction of metal X with Fe2O3 is highly exothermic
and is used to join railway tracks. Identify metal X.Write the
chemical equation for the reaction.

3. In electrolytic refining of impure copper metal, what are used as
cathode and anode?

4.
Why is carbon not used for reducing aluminium oxide
to obtain Al?
or
Metals placed high in reactivity series cannot be
obtained from their compounds by heating with
carbon?

5. What is cinnabar? How is metal extracted from cinnabar? Explain
briefly.
.

E] Alloying & Corrosion:

1. Why do we apply paint on iron grills?

2. Why does stainless steel not get rusted easily?

3. Why do aluminium sheets not corrode easily?

4. How do properties of iron change when
a. a small quantity of carbon is mixed in it?
b. nickel and chromium are mixed in it?

5. In one of the methods of rust prevention, iron is not coated with
anything. Name that method and define it.

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