Aluminium powder is used in thermit welding because :

Aluminium powder is used in thermit welding because :
  1. Its reaction with iron is highly exothermic.
  2. When it is heated with iron (III) oxide, molten iron is obtained.
  3. When it is heated with iron (III) oxide, molten aluminium oxide is obtained to join railway tracks.
  4. Its melting point is low as compared to iron and a molten alloy of iron and aluminium is formed on heating which is used to join railway tracks.

Solution

When it is heated with iron (III) oxide, molten iron is obtained.

Asked in: CBSE

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