The compound sodium thiosulfate pentahydrate, Na2S2O3路5 H2O, is important commercially to the photography busi

The compound sodium thiosulfate pentahydrate, Na2S2O3路5 H2O, is important commercially to the photography business as "hypo," because it has the ability to dissolve unreacted silver salts from photographic film during development. Sodium thiosulfate pentahydrate can be produced by boiling elemental sulfur in an aqueous solution of sodium sulfite.
S8(s) + Na2SO3(aq) + H2O(l)= Na2S2O3路5 H2O(s) (unbalanced)
What is the theoretical yield of sodium thiosulfate pentahydrate when 3.31 g of sulfur is boiled with 15.3 g of sodium sulfite?
g

Sodium thiosulfate pentahydrate is very soluble in water. What is the percent yield of the synthesis if a student doing this experiment is able to isolate (collect) only 0.5 g of the product?
%

First balence the reaction:
(1/8)S8(s) + Na2SO3(aq) + 5H2O(l)= Na2S2O3路5 H2O(s)
Here I am use non-integral reaction coefficient for S8. This equation says that one mole of ATOMIC S can react with one mole of Na2SO3 to form one mole of Na2S2O3路5 H2O.
Second find the molar masses:
S atom: 32.065 g/mol
Na2SO3: 126.0418 g/mol
Na2S2O3路5 H2O: 248.183 g/mol
Therefore:
3.31g S is 0.103 mole of Atomic S
15.3g Na2SO3 is 0.121 mole of Na2SO3.
We have less moles of S, thus S is the limiting reactant. The theoretical yield of sodium thiosulfate pentahydrate is:
0.103*248.183 = 25.6 (g)
The percent yield of the poor synthesis by the student is:
(0.5g)/(25.6g) = 2%.