Question

Review Problem 6.086 Given the following thermochemical equations, 2Cu + S(s) - Cu2S(s) AH° = -79.5 kJ S(s) + O2(g) → SO2(9) AH = -297 kJ Cu2S(s) + 202(g) → 2CụO(s) + SO2(g) AH° = -527.5 kJ calculate the standard enthalpy of formation (in kilojoules per mole) of Cuo(s). AH°(Cuo(s)) - kJ/mol The number of significant digits is set to 3; the tolerance is +/-2% Show Work is REQUIRED for this question: Open Show Work

Answer 1

@ 8.6086 2 Cu(s) + 5(0) - Cugs. AH = -795 kJ 5(1) + 0₂ (8) - S0₂ (8) , DH = - 297 kJ CU, S(1) + 20, 0) –> 2 CuOle) + S02 () — 3 OH = -527.5kJ Reaction for formation of cuo (+) Cu (2) + O2 (g) Cuo(s), DH = x ? In for getting this reaction. 60 +) we get 2 Cus) + 20 (8) 2 cuo - & OH = OH - PH₂ + I AH3 1H=1-79.5+297-527.5) kJ =-310kJ dende by 2 Cu (8) + 1/ 02 (8) CuO (6) DHA DH =-310 kJ = - 155kJ Ay

0.6.087 given 3Mg(s) + 2NH3 (8) Mg ₂ N₂ + 3H₂ Dni = ~371 kJ 12 N2 (8) + 3 H2 18) - NH₃(g) o DH = - 46 kJ 3 Mg(s) + N2 (8) - Mg ₂ N2(), DHg = ? we can see that equ 0 = 0 + 2x② ③ : DH₂ = Ahi + 2xAHz = -371 + 12x-46) = - 37 -92 = - 463 kJ
rest questions can be done by same method .

During formation, we make one mole of given product using reactants in their standard state.