If you know ,please let me know .

 

 

Thank you.

sorry

 

Al does not react with nitric acid ??? Reason

Because it has a protective layer of aluminium oxide, which is not soluble in nitric acid. This is, in general, why aluminium is resistant to furtehr oxidation or other forms of corrosion.

yes it has protective layer of aluminium oxide, but it reacts with other acids like HCl and sulphuric acid.

 

you want to say that aluminium oxide is unreactive with nirtic acid , WHY ????

Resistance to oxidation is very complicated, completely experimental, and explanations are better sought after the observations are made...

 

Few aluminium alloys resist corrosion. Al-Cu and Al-Zn don't. Al-Mg, Al-MgSi and pure Al have better chances.

 

Cl^- is known to botch the alumine layer, independently of the acid. Seawater corrodes most aluminium alloys that way, without acidity.

 

Nitric acid is mild to aluminium because it provides oxygen, hence reconstitutes the alumine layer, and is a weak acid. Pure nitric acid would not attack mild steel neither. But, well, if nitric did attack aluminium, we'd have found some convincing explanation as well...