2SO2(g) + O2(g) >2SO3(g). If 96g SO2 is added to 2 moles of oxygen at STP, calculate the mass of SO3 that is formed

Answer 1

This is a limiting reagent problem. You know that because amounts are given for BOTH reactants.
2SO2 + O2 ==> 2SO3
mols sO2 = grams/molar mass
mols O2 = 2

Using the coefficients in the balanced equation convert mols SO2 to mols SO3.
Do the same for mols O2 to mols SO3.
It is likely that these two values will not agree which means one of them is wrong. The correct value in limiting reagent problems is ALWAYS the smaller value and the reagent producing that value is the limiting reagent.
Now convert mols SO3 to grams. g = mols x molar mass.

Answer 2

The molar mass of SO3 is 80g.mol to the power -1 and we have 2 moles...so the mass is 80g.mol to the power -1 x 2 mol..the answer will be 160 g

Answer 3

Calculate the mass and volume of oxygen released when 29.4g pottasium chlorate decomposes to form pottasium chloride and oxygen