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 given below. Fe2O3(s) + 2 Al(s) 2 Fe(l) + Al2O3(s) What masses of iron(III) oxide and aluminum must be used to produce 12.0 g iron? iron (III) oxide WebAssign will check your answer for the correct number of significant figures. 17.2 Correct: Your answer is correct. g aluminum WebAssign will check your answer for the correct number of significant figures. 2.98 Incorrect: Your answer is incorrect. g What is the maximum mass of aluminum oxide that could be produced?

Answer 1

• 1. Iron(III) oxide: 17.2 g

• 2. Aluminum: 5.80 g

• 3. Aluminum oxide: 11.0g

Step-by-step explanation:

1. Chemical reaction (given)

`Fe_2O_3(s)+2Al(s)\rightarrow 2Fe(l) + Al_2O_3(s)`

2. Mole ratios

`1molFe_2O_3(s):2molAl(s):2molFe(l):1molAl_2O_3(s)`

3. Convert 12.0g of iron to moles

• atomic mass of Fe: 55.845g/mol

• number of moles = mass in grams / atomic mass

• number of moles = 12.0g / 55.845g/mol = 0.215mol

4. Iron(III) oxide

• molar mass Fe₂O₃: 159.69 g/mol

• mole ratio: 1 mol Fe₂O₃ : 2 mol Fe

`0.215molFe* (1molFe_2O_3)/(2molFe)* 159.69g/mol=17.2g`

5. Aluminum

• atomic mass Al: 26.982g/mol

• mole ratio: 2 mol Al : 2 mol Fe

`0.215molFe* (2molAl)/(2molFe)* 26.982g/mol=5.80g`

6. Aluminum oxide

• molar mass Al₂O₃: 101.96g/mol

• mole ratio: 2mol Fe: 1 mol Al₂O₃

`0.215molFe* (1molAl_2O_3)/(2molFe)* 101.96g/mol=11.0g`