Question

Be sure to give your answers with the correct number of significant figures. 1. 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: Fe20. (s) + 2Al(s) – 2Fe (1) + Al O2 (s) a. How many moles of iron (III) oxide must react in order to produce 3.5 mol of Fe? (1.25pts) b. What mass of iron (III) oxide reacted in order to produce 3.5 mol of Fe? (1.25pts) c. If 3.6 g of iron (III) oxide completely reacts, how much Al,0, (in grams) can be produced? (1.25pts) d. If 3.6 g of Al; 0; is produced during the reaction, how many grams of molten iron is produced? (1.25pts)

Answer 1

Given reaction fe, O2 W) + 2Al(s) → 2 few + Alz 03 (3) a) mole of fe = 315 mol 2.0 mol of fe is produced by I mol of fe₂O3 .. 1.0 mol of fe is produced by homol of fez O₃ :.315 mol of fe is produced by 3.5 mol of fez Oz i mol of fe2O₃ = 1.175 mol = 118 mol (rounded to correct number of significant figure ,

b) mole of fe2O3 reacted a 1.75 mol Mw of fe₂O₃ = 159.7 g/mol - mass of fe2O3 = mol xMw = 1.75 mol x 189.7 g/mol - 279.4759 = 299 g (rounded to correct number of Significant figure) or 2809

c) mass of fez a = 3.6g Mole of fe2O: 36g 159.78/mol now, I mol of fe₂O, reacts to produce I mol of Al2O3 - 3.6 mol of fez reacts to produce 3:1 mol of Ad,O, 1597 So, mol of Ah,03 produced : 3 mol Mw of Al2O3 = 101.96 g/mol So, mass of Al2O, produced molx Mw = 3.6 milx 101.969/mol 159.7 2.298 9 ĉ 2.39 ( rounded to correct number of significant figure d) mass of AdzOg produced = 3.6g so, mol of Al2O3 = Griven may = 3.6 g Mw 10:969/mol " I mol of Al2O3 is produced along with 2 mol of te ..mer mol of Atzoz is produced along with 20X 346 mol dite so, mol of fe produced = 2 1083.6 mol 101.96 so, mass of fe produced molx Mw = 2¢0x3,6 x 55.85 g 101.96 Tol = 3.9449 ř 3.99 (rounded to correct number of significant figure)