Given the following reactions and their enthalpies: AH(kJ/mol) H;(g) 2H(g) 20(g) +436 O:(g) +495 H,(g) + 0,(g) → H,O(g) -242 (a) Devise a way to calculate AH for the reaction H,O(g) - 2H(g) + O(g) (b) From this, estimate the H-O bond energy.

(c) Consider the following chemical reaction: C;Hs(g) + H2(g) C2H6(g) + CH4(g) ΔΗ? %3D Calculate the enthalpy change for the reaction above using Hess's law. Thermochemical dat: H:(g) + ½O2(g) H2O(1) AH° =-285.8 kJ AH°combustion for CH4(g) AH° =-890.0 kJ/mol %3D CO:(g) C(s. graphite) + O:(g) AH° = +393.5 kJ AH°combustion for C2H6(g) AH = -1560.0 kJ/mol AH°, for C3H$(g) AH° =-103.8 kJ/mol

Calculate the standard enthalpy change for the reaction 2CgHial) - 1702ig) – 16COg) + 18H200- Given 2C;H1s1)+ 250;(g) 16CO:(g) + 18H;O(1) AH-11,020 kJ/mol 2Co0g) + O:g) 2CO2(g) AH° --566.0 kJ/mol Multple Choice -10.450 kimol -6.492 kimol O 15.550 kmol 10.460 kimol O 6,492 kJimel

(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

Calculate the standard enthalpy of formation for C3H6O (l) from its combustion using the following data: Enthalpy of this combustion is -1793 kJ ( you must write a balanced reaction first).

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.

Substance SiO,(s) SICLO H,O) HCIE) AH°, (kJ/mol) -910.7 -687.0 -285.83 -92.307 Calculate the standard enthalpy change for the following reaction: SICI4(1) + 2H20(1) → SIO2 (s) + 4HCI (g)

(3)

Using the provided table, determine the enthalpy (in kJ/ mol) for the reaction 2 NH3 (g) + 3 N,0 (g)→ 4 N, (g) + З Н,0 () Substance AH{ (kJ/mol) NH3 (g) -46.2 N20 (g) 81.6 N2 (g) H2O (1) -285.8

（1）Consider the reaction: 2A (g) + 3 B (g) → 2 C (g)     ΔHrxn = +254.3 kJ What will be the enthalpy change (in kJ) if 0.471 mol B reacts in excess A?   （2）Consider the reaction: C (s) + O2 (g) → CO2 (g)     ΔHrxn = -393.5 kJ What mass of carbon (in g) must be reacted via this mechanism to release 581.2 kJ of heat?