1) Balanced chemical equation:
2SO2 (g) + O2 (g) -> 2SO3 (l)
2) Molar ratios
2 mol SO2 : 1 mol O2 : 2 mol SO3
3) Convert 6.00 g O2 to moles
number of moles = mass in grams / molar mass
number of moles = 6.00 g / 32 g/mol = 0.1875 mol O2.
4) Use proportions with the molar ratios
=> 2 moles SO2 / 1 mol O2 = x / 0.1875 mol O2
=> x = 0.1875 mol O2 * 2 mol SO2 / 1 mol O2 = 0.375 mol SO2.
5) Convert 0.375 mol SO2 to grams
mass in grams = number of moles * molar mass
molar mass SO2 = 32 g/mol + 2*16 g/mol = 64 g/mol
=> mass SO2 = 0.375 mol * 64 g / mol = 24.0 g
Answer: 24.0 g of SO2 are needed to react completely with 6.00 g O2.
No, the water is not different it is just that the units of measurement in the US is different then those units in Europe. This is similar to how the US uses miles and Europe uses kilometers
Answer: 34.4 g
Explanation:
As 
is in excess, 
is the limiting reagent and thus it will limit the formation of products.
According to stoichiometry:
2 moles of hydrogen produce = 1 mole of 
2.5 moles of hydrogen produce = 
of
Mass of 
But as % yield is 86%, mass of produded is 
Thus 34.4 g of is produced.
Since the volume decreased, it means that the pressure is going to rise. Thus, the equilibrium of the reaction will shift in the direction that has the least amount of moles.
