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 Fe, Os() + 2Al() + 2Fe(l) + Al, Os(-) a What mass of iron(III)oxide must be used to produce 15.7 g iton? Mass- b. What mass of aluminum must be used to produce 15.7 g iron? Mass- c. What is the maximum mass of aluminum oxide that could be produced? Mass- Submit Answer Try Another Version Sitem attempts remaining

Answer 1

a)

Molar mass of Fe = 55.85 g/mol

mass of Fe = 15.7 g

mol of Fe = (mass)/(molar mass)

= 15.7/55.85

= 0.2811 mol

According to balanced equation

mol of Fe2O3 used = (1/2)* moles of Fe

= (1/2)*0.2811

= 0.1406 mol

Molar mass of Fe2O3,

MM = 2*MM(Fe) + 3*MM(O)

= 2*55.85 + 3*16.0

= 159.7 g/mol

mass of Fe2O3 = number of mol * molar mass

= 0.1406*1.597*10^2

= 22.45 g

Answer: 22.5 g

b)

According to balanced equation

mol of Al formed = moles of Fe

= 0.2811 mol

Molar mass of Al = 26.98 g/mol

mass of Al = number of mol * molar mass

= 0.2811*26.98

= 7.584 g

Answer: 7.58 g

c)

According to balanced equation

mol of Al2O3 formed = (1/2)* moles of Fe

= (1/2)*0.2811

= 0.1406 mol

Molar mass of Al2O3,

MM = 2*MM(Al) + 3*MM(O)

= 2*26.98 + 3*16.0

= 101.96 g/mol

mass of Al2O3 = number of mol * molar mass

= 0.1406*1.02*10^2

= 14.33 g

Answer: 14.3 g