Use your results from #4 and data Table 8.1 to calculate the value of DHf for Mg†² (aq) Note: You must write out the formation equations of all products and reactants and sum to find the change in enthalpy for the formation of the cation (like example 8.3). Failure to do so will result in zero credit.

Determine the enthalpy of the reaction: 3Fe,O; (s) + CO (g) → CO, (g) + 2Fe;O4 (s), given the following reactions. 38. Fe,O3 (s) + 3CO (g) → 2Fe (s) + 3CO, (g) AH= -28.0 kJ 3Fe (s) + 4CO2 (s) → 4CO (g) + Fe;O4 (s) AH =+12.5 kJ A) 40.5 +109 -59.0 -109

Find the enthalpy of reaction for the equation: H2SO4laq) + 2NAOH(aq)-Na,SO,(aq) + 2H20(), AH=? Using the following equations whose enthalpy is known (please round your answer to the tenths place): H2(g) + S(s) + 202(g) – H2SO,(aq), AH= -907.5 kJ Na(s)+ ½H2(g) + ½O2{g) – NaOH(aq), AH= -469.6 kJ 2Na(s) + S(s) + 20,(g) – Na,SOal(aq). AH= -1387.1 kJ H2(8) + ½O2(g) – H2O(1). AH= -285.8 kJ AH= kJ.

(b) An aqueous solution of acetic acid can be prepared by the reaction of ethanol with oxygen : CH3CH2OH (1) + O2 (g) –→ CH3COOH (1) + H2O (1) Write thermochemical equations for enthalpy of formation of the given compounds and calculate AH for the reaction, given the following data. Enthalpy of formation, AHf (kJmol") -277.8 Compound CH;CH2OH (1) CH3COOH (I) H2O (1) -485.0 -286.0

The first step in the production of nitric acid from ammonia involves the oxidation of NH3. 4 NH3(g) + 5 O₂ (g) → 4 NO(g) + 6 H₂O(g) 2 a Use standard enthalpies of formation from the table below to calculate the standard enthalpy change for this reaction. Species AfH (kJ/mol) NH3(g) -45.90 NO(g) +90.29 H₂O(g) -241.83 Standard enthalpy change Submit = kJ/mol-rxn

28. Write the equation that corresponds to the standard enthalpy of formation for each of the following compounds: a) NaI(s), b) HC1O,(g), and c) CH;OCH;(g)

2. Calculating enthalpy: AH = -206 kJ mol¹¹, 3 Fe(s) + 2 O₂(g) → Fe3O4 (S) AH = -136 kJ mol-¹, a) Given 2Fe(s) + 1.5 O₂(g) → Fe₂O3 (S) determine AH, for the following reaction: 4Fe₂O3(s) + Fe(s) → 3Fe3O4 (s) Is this reaction exothermic or endothermic? Is this enough information to inform whether this reaction occurs or not? O b) Given AH vap of water at 373 K = 40.7 kJ mol¹¹, C₂(l)=75.2 J mol¹¹K²¹ and ₂(g)=33.6 J mol¹¹K²¹, calculate AHvap of water at 298 K.

15. Using the standard enthalpies of formation for the chemicals involved, calculate the enthalpy change for the following reaction. (Note: Show the math clearly and provide units in your setup) (AH; Values in kJ/mol are as follows: NO, +32, H,0 -286, HNO3 -207, NO +90) 3NO2(8) + H,Oy O 2HNO3(aq) + NO(g) (g),

Use the molar bond enthalpy data in the table to estimate the value of AHin for the equation. rxn NH3(g) + 2O₂(g) → HNO3(g) + H₂O(g) The bonding in the molecules is shown. H AHixn = H O اس ای H + Bond O-H 0-0 C-O 0=0 C=O C-C C=C C=C C-H C-F C-Cl C-Br C-N C=N kJ. mol-¹ 464 142 351 502 730 347 615 811 414 439 331 276 293 615 Bond C=N N-H N-O N=N N=O F-F Cl-Cl Br-Br H-H H-F H-Cl H-Br H-S S-S kJ · mol-¹ 890 390 201 418 607 155 243 192 435 565 431 368 364 225 kJ.mol-¹