Lets number the reaction as 1, 2, 3, 4 from top to bottom
required reaction should be written in terms of other reaction
This is Hess Law
required reaction can be written as:
reaction 4 = +1 * (reaction 1) +2 * (reaction 2) +1 * (reaction 3)
So, ΔHo rxn for required reaction will be:
ΔHo rxn = +1 * ΔHo rxn(reaction 1) +2 * ΔHo rxn(reaction 2) +1 * ΔHo rxn(reaction 3)
= +1 * (-1300.0) +2 * (393.5) +1 * (227.0)
= -286.0 KJ
Answer: -286.0 KJ
Hess's Law Given the following data: C2H2(g) + 5/202(9) + 2002/9) + H20(1) AH' = -1300.0...
loab beboo 2CO2 + H2O. 7. Calculate AH for C2H2 +5/202 Given C(s) +O2(g) CO2(g) AH = -393.5 kJ H2+½ O2 H2O AH= -285.8 kJ 2C+H2 C2H2 AH = 226.8 kJ 008700000 08.0 Lon Qoe cOeEo.O60
3. Given the following data: C2H2 (8) +5/2O2(g) → 2CO2 (g) + H20 (1) = - 1300. KJ C(s) + O2(g) → CO2 (g) = -394 kJ H2(g) + 1/2O2(g) → H20 (1) = -286 kJ Calculate for the reaction 2C(s) + H2(g) → C2H2 (8)
Find AHrxn for: C2H2(g) → 2C(s) + H2(g) given the following information: C2H2(g) + 5/2 O2(g) → 2002(g) + H2O (1) AH° = -1291 kJ C(s) + O2(g) + CO2(g) AH° = -391 kJ H2(g) + 1/2O2(g) + H2O(1) AH° = -280 kJ kJ
Given the following equations and AH' values: C(s) + O2(g) + CO2(g) AH = -393.5 kJ H2(g) + 1/2O2(g) - H20 (1) AH = -285.8 kJ 2C2H2 (8) + 5O2(g) + 4CO2(g) + 2H20 (1) AH'= -2598 kJ Determine the heat of reaction (in kJ) at 298 K for the reaction: 2C(s) + H2(8) C2H2 (8) 0-136.8 0-219.8 0-109.9 O-167.1 +226.2
Hess's Law (b) Given the following thermochemical data: 2HNO3(aq) +A920(s) - H2O(1) +2AgNO3(aq) AH = -44.8 kJ Ag20(s) - 2Ag(s) + 1/2O2(9) AH = 31.0 kj H20(1) - H2(9)+1/202(9) AH = 285.8 kJ Use Hess's Law to determine AH for the reaction: Ag(s)+HNO3(aq) → 12H2(9)+AgNO3(aq) AH =
Consider the following data. 2 C(s) + H2(g) C2H2(g) H = +226.8 kJ CO2(g) C(s) + O2(g) H = +393.5 kJ 2 H2O(l) 2 H2(g) + O2(g) H = +571.7 kJ Use Hess's law to calculate H for the reaction below. 2 C2H2(g) + 5 O2(g) 4 CO2(g) + 2 H2O(l) find kJ
Calculate the value of AH° for the reaction 2 C2H2 () + 502 () 4002) + 2 H20 (1) given the following thermochemical equations: AH° = - 242 kJ AH° = - 394 kJ H2(g) + 4202) → H20 (8) C(s) + O2(%) + CO2(8) 2 C(s) + H2(g) → C2H2 (6) H20 () → H30Ⓡ AH° = +227 kJ AH° = +44 kJ TO - 907 kJ 0 - 2602 kJ 0 - 2514 kJ - 1694 kJ
6. Hess's Law. Use the data in Table 1 to calculate AH for the reaction below: Table 1. Change in Enthalpy for Reactions Reactions Change in Enthalpy (AH) AH = -393.5 kJ/mol (1) C() (2) Hz((g) + + O2(g) O2(g) → CO2(8) → H2O(l) AH2 = -285.8 kJ/mol (3) 2CH.(g) + 702(g) → 4 CO2(g)+ 6H2O(1) AH = -283.0 kJ/mol Calculate the enthalpy change for the reaction: 2 C(s) + 3H2(g) → CzH6(g) AH = kJ/mol
6. Hess's Law. Use the data in Table 1 to calculate AH for the reaction below: Table 1. Change in Enthalpy for Reactions Reactions Change in Enthalpy (AH) AH = -393.5 kJ/mol (1) C() (2) Hz((g) + + O2(g) O2(g) → CO2(8) → H2O(l) AH2 = -285.8 kJ/mol (3) 2CH.(g) + 702(g) → 4 CO2(g)+ 6H2O(1) AH = -283.0 kJ/mol Calculate the enthalpy change for the reaction: 2 C(s) + 3H2(g) → CzH6(g) AH = kJ/mol
Practice with Hess's Law and Standard Heats of Formation 1. (Example) The reaction C2H4 (g) + 6 F2 (g) → 2 CF4(g) + 4 HF (g) can be written as the sum of: C2H4 (9) ► 2 C(s) + 2 H2 (g) AH = -52.3 kJ/mol 2 C(s) + 4 F2 (9) ► 2 CF4(9) AH = -1360 kJ/mol 2 H2(g) + 2 F2 (g) → 4 HF (a) AH = -1074 kJ/mol C2H4(g) + 6 F2(g) → 2 CF4(g)...