A compound contains 3.2% of oxygen. The minimum mol. wt. of the compound is

The compound must contain at least one oxygen atom So, a minimum of 1 g atom of oxygen will be present in 1 g molecule, i.e., 1 mole of the compound.If M is the mol.wt. of the compound then since 16 is the atomic mass of oxygen so minimum of 16 g of oxygen will be present in M g of the compoundThus,  %  of  oxygen=16M× 100or   3.2=16× 100 Mor    M=500