Question

Give reason

1. Aluminum is more reactive than iron yet there is less corrosion of aluminum as compared to iron when both are exposed to air.

2. Tarnished copper vessels are cleaned with tamrind juice.

Answer 1

1)
Aluminum develops a protective layer of aluminum oxide by slowly reacting with oxygen present in air.

After this layer formation , air can't react with aluminum present,hence there is only less corrosion.

In compare , iron can't form protective layer hence it easily gets corroded.

2)

Lemon juice contains citric acid and tamarind contains tartaric acid. These adds react with basic layer of copper carbonate on the surface to form soluble salts which are easily removed and surface shines.