The number above the symbol is the atomic mass (or atomic weight). This is the total number of protons and neutrons in an atom. The number below the symbol is the atomic number and this reflects the number of protons in the nucleus of each element's atom. Every element has a unique atomic number.
The theoretical yield is 204.4 g while the percent yield is 2.57%.
<h3>What is theoretical yield?</h3>
Theoretical yield is the amount of product obtained based on the stoichiometry of the reaction.
S8(s) + 8 Na2SO3(aq) + 40 H2O(l) --->8 Na2S2O3·5 H2O(s)
Number of moles of sulfur = 3.25 g /8(32) = 0.013 moles
Number of moles of sodium sulfite = 13.1 g/126 g/mol = 0.103 moles
Since 1 moles of sulfur reacts with 8 moles of sodium sulfite
0.013 moles reacts with 0.013 moles × 8 moles /1 mole = 0.104 moles
There is not enough sodium sulfite hence it is the limiting reactant.
1 mole of sodium sulfite yields 8 moles of product
0.103 moles of sodium sulfite yields 0.103 moles × 8 moles /1 mole = 0.824 moles
Mass of product = 0.824 moles × 248 g/mol = 204.4 g
percent yield = 5.26 g /204.4 g × 100/1
= 2.57%
Learn more about percent yield: brainly.com/question/2506978
