#"Avogadro's number"# of silicon atoms has a mass of #28.1*g#; that is #6.022xx10^23# individual silicon atoms express this mass.....
And thus we calculate the molar quantity of silicon atoms....and thus...
#(1.08xx10^23*cancel"silicon atoms")/(6.022xx10^23*cancel"silicon atoms"*cancel(mol^-1))xx28.086*g*cancel(mol^-1)#
#~=5*g#.
How much oxygen would we need to form 1 equiv #SiO_2#?
If you can appreciate this concept of #"chemical equivalence"#, that a given mass of atoms represents a precise number of same, and vice versa, and learn how to apply in actual problems, you will be doing better than most of your colleagues. Don't forget to try to help them appreciate the concept. This will be good for them, and also good for you.
