ΔΗ = C = N (891 kJ/mol) C-N (305 kJ/mol) H-H (432 kJ/mol) CH (413 kJ/mol) N - H (391 kJ/mol) ΔΗ = b. Use bond energy values to estimate AH for the following reaction. N - N kJ H-F (160. kJ/mol) (565 kJ/mol) (391 kJ/mol) N = N(941 kJ/mol) F-F (154 kJ/mol) N - H N- H (g) +2F₂(g) H kJ N=N(g) + 4HF(g)

For the reaction below, calculate the enthalpy change using the appropriate bond energies in the table on the next page. C3H8(g) + 5O2(g)à3CO2(g)+ 4H2O(g)

True or False: This reaction is endothermic because more energy is needed to break up the reactants versus the amount given off by the products. Use the reaction and bond information to answer the question. H-H +0=C = 0 - H-C = O | O-H H2 + CO, → CH,O. Reactant bond energies: H-H is 432 kJ/mol, C=O is 799 kJ/mol Product bond energies: C-H is 413 kJ/mol, C=O is 745 kJ/mol, C-O is 358 kJ/mol, O-H is 467 kJ/mol ○ True ○ False 1

2. Use the table below to estimate AH for the reaction NO + O3 → NO2 + O2. Does this reaction consume or produce heat? Single Bond Energies (kJ/mol of bonds) н сN oS F C Br I Н 436 C 413 346 N 391 305 163 O 463 358 201 146 S 347 272 226 - F 565 485 283 190 284 155 Cl 432 339 192 218 255 253 242 Br 366 285 201 217 249 216 193 - I 299 213 201 278 208 175 151 - - Multiple Bond Energies (kJ/mol of bonds) C=C 602 C=N 615 C=O 799 C=C 835 CEN 887 C=O 1072 N=N 418 N=O 607 N=N 945 O=O 498