Fe produced : 27.53 g
Reaction
Fe₃O₄ + 4H₂ = 3Fe + 4H₂O
mol Fe₃O₄ (MW=233.55 g/mol) :
[tex]\tt \dfrac{49}{233.55 g/mol}=0.21[/tex]
mol ratio Fe₃O₄ : Fe = 1 : 3, so mol Fe :
[tex]\tt 3\times 0.21=0.63~g/mol[/tex]
mass Fe(Ar=55,845 g/mol)
[tex]\tt 0.63\times 55,845=35.18~g[/tex]
grams produced :
[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=78.25\%\times 35.18\\\\actual=27.53~g[/tex]