57.0 is it rounded to three sig figs. You count three spaces then round from there, which would be the zero and you would round down because the four is there.
a. mass of iron = 69.92 g
b. percent yield = 93%
<h3>Further eplanation
</h3>
Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
a.
Reaction
Fe₂O₃+3CO⇒2Fe+3CO₂
MW Fe₂O₃ : 159.69 g/mol
mol Fe₂O₃

mol Fe₂O₃ : mol Fe = 1 : 2
mol Fe :

mass of Fe(Ar=55.845 g/mol) :

b.
actual yield = 65 g
theoretical yield = 69.92 g
percent yield :

Answer:Astrobiology, formerly known as exobiology, is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe.
Explanation:
Answer:
Respiración anaerobica
Explicación:
Las nuevas especies carecen de mitocondrias, por lo que realizan respiración anaeróbica porque en las mitocondrias solo ocurre la respiración aeróbica mientras que la respiración anaeróbica ocurre en el citoplasma de la célula. Trabajar en armonía es muy importante para el funcionamiento normal de su cuerpo. Por ejemplo, el funcionamiento combinado del sistema circulatorio y excretor. ambos sistemas hacen su trabajo mutuamente y por eso hay armonía en el cuerpo.