1. PROBLEM 4 OF LIMITING REAGENT SET
PROBLEM 4 OF LIMITING REAGENT SET. 2S (s) + 3O2 (g)  2SO3 (g) FIRST DETERMINE IF THERE IS A LIMITING REAGENT. / FIND MOLES OF ALUMINUM METAL FIND MOLES OF OXYGEN GAS.
MOLES = MASS/GFM S
MOLES = 1.0 g s/ 32.04g/mol
MOLES = mol S
MOLES = MASS/GFM O2
MOLES = 1.0 g O2 / 32.00g/mol
MOLES = mol O2
S = = , O
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The actual ratio is larger than the theoretical, therefore the actual ratio fraction is too large, the denominator is to small, O2 limiting.

2. 2S (s) + 3O2 (g)  2SO3 (g)
STEP 1 Identify known (the substance that can be converted to moles), choose the correct equation to convert to moles.
MOLES = MASS/GFM O2
MOLES = 1.0 g O2 / 32.00g/mol
MOLES = mol O2
STEP 2 RATIO known to objective,
O = = ,
SO X X = mol SO3
STEP 3 Convert Objective to required units.
MOLES = MASS/GFM SO3
mol= mass/ 80.06g/mol
Mass = g SO3
% yield = experimental/theoretical
0.80 / =47.9% = 48%