The same number of nitrogen molecules as 25.00 g of oxygen?

Answer 1

I assume you mean the same number of nitrogen molecules as there are oxygen molecules in 25.00 g oxygen, although I do not understand why the question is asked in such a confusing way (probably not your fault; I'm afraid some textbooks are like that).

Number of moles = mass divided by molar mass (in this case the molar mass of O2

Number of molecules = number of moles x avogadro's number

That's all there is to it!