NEETChemistryp Block Elements (Group 15, 16, 17 & 18)
Why do some metals like Cr and Al not dissolve in concentrated nitric acid?
Options
- ABecause they form passive films of oxide on the surface
- BBecause they react violently with the acid
- CBecause they are noble metals
- DBecause they are insoluble in all acids
Correct answer
A. Because they form passive films of oxide on the surface
Step-by-step solution
The paragraph explains that some metals like Cr and Al do not dissolve in concentrated nitric acid because they form passive films of oxide on the surface.