chemistry
posted by Ralph .
How many moles of oxygen are there in 23.5g of H2SO4? (numbers are subscripts)How many oxygen atoms? How many grams of oxygen?

23.5 g H2SO4 = ?? moles.
23.5/98 = ?? moles H2SO4.
There are 4 moles O atoms in 1 mole H2SO4; therefore, moles H2SO4 x 4 = ??
There are 6.02 x 10^23 atoms in a mole of atoms; therefore, # moles oxygen atoms x 6.02 x 10^23 atoms = ??
grams oxygen = moles oxygen x 16 g/mole = ?? 
MASS OF OXYGEN IN 23.5g of H2SO4=2(M of oxygen)/M of H2SO4
=2(16g/mol)/2(1)+32.07+4(16)
=32/98.07
=0.33 grams
n=m/M
n=0.32g/16 g/mol
n=0.02 moles 
number of oxygen atoms=number of moles(Avogadro's constant)=0.02moles( 6.02*10^23)
=1.22............... you know