Question

3. (14 pts.) The standard molar enthalpy of formation of Fe,Oxs is AH = -8242 kJ/mol, and the standard molar enthalpy of formation of SO2(g) is AH = -296.8 kJ/mol (both at 298 K). Use this information, along with the standard molar enthalpy change of the following reaction at 298K, 2 FeS21s) + 11/2O2(g) → Fe2O3 + 4 SO2(g) AH = -1655 kJ/mol To determine the standard molar enthalpy change of the reaction shown below are 298 K: Fe(s) + 2 Sis) → FeS2) Note: The standard state of iron is Fe(s) and the standard state of sulfur is S(s) at 298 K.]

Answer 1

Given that, Standard molar 2 Few + 306 enthalpy of formation of Feels Fez o (s), on = -824.2 Kg mał Standard ehthalpy of formation of So, (g) Sat 02 SP2 (3) (2 sn= - Kg mot 2Fe Sq (S) + L 0,(9) ► Feels (5) +45°2 (3) -43) 1 An = -1655 KI moe Multiplying eqn 6 by % and 2 by 2 and then adding, F Q4 2013 Fez's B) An°2-824.2 -412.7, 25+ 20,691 2 502 (7) An's 28-296.8 =-593.6 Kg mał Feis) + 2 589) +4 013->Fe2O3(3 +289, -(1) on=-412-)-5936 3-1005.7 Kg med Multiplying can o by / and reversing, + Flegos 13 Fe (s) + 3 02 (2) Ana 2 Kamal' Multiplying Eqr ③ by Y and revessing, t Fost 250 g - FeS₂ (S) + 1₂ 19, –6 Sn =+827.5kg moal Scanned with CamScanner o f

Adding care 9 4 6 we get, Te (5)+28 (5+ 82 83 → 15.04(+2,56,193 sh=-1005. 7 kg mał! I ens + 250 (9) Faisst 14 gelas on = 827.5 kg mał Fest 25 (3) Fee S2 (s. o n' =-1005:7 +827.5). =-178.2 kg mat!