Question

Over the years, the thermite reaction has been used for welding railroad rails, in incendiary bombs, and to ignite solid fuel rocket motors. The reaction is Fe2O3(s) + 2Al(s) → 2Fe(l) + Al2O3(s) What mass of aluminum must be used to produce 36.89 g of iron? g

Answer 1

Fe2O3(s) + 2Al(s) ------------------> 2Fe(l) + Al2O3(s)

no of moles = mass / molar mass

for Fe = 36.89g / 55.845 g/mol = 0.660578 moles

mole ratio of fe and al is as follows

2 moles Al ------------------------> 2 moles Fe

? -------------------------------------> 0.660578 moles

=> 0.660578 moles of Al

mass of Al = 0.660578 moles * 26.98g/mol = 17.82 grams

answer => 17.82 g of aluminium