N-N H-S-C -S-H

5. For the reaction H2(g) + C2H4(g) C2H6(g) (a) Estimate the enthalpy of reaction, using the bond enthalpy values. (b) Calculate the enthalpy of reaction, using standard enthalpies of formation. (AH? for H2, C2H4, and C2H6 are 0 kJ/mol, 52.3 kJ/mol, and -84.7 kJ/mol, respectively.)

The two compounds nitrogen dioxide and dinitrogentetraoxide are introduced in Section 3.13.(a)  NO2 is an odd-electron compound. Draw the bestLewis diagrams possible for it, recognizing that oneatom cannot achieve an octet configuration. Use formal charges to decide whether that should be the(central) nitrogen atom or one of the oxygen atoms.(b)  Draw resonance forms for N2O4 that obey the octetrule. The two N atoms are bonded in this molecule.

Calculate the enthalpy change for the following reactions using the bond enthalpy given below. (Bond enthalpy/kJ : H−H = 436, C−H = 413, C=O = 799, O=O = 495, O−H = 463) (a)  H2(g) + 1⁄2O2(g) → H2O(g) (b)  CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)

Draw a Lewis structure for each of the following                                        molecule:                                                     (a) chlorodifluoromethane, CHCIF2                                                               (b) propanoic acid C2H5CO2H (basic structure                                                  pictured below)                                                                                                                                                                                                                                                                                                                                                                                                                                                              (c) acetonitrile, CH3CN ( the framework is H3C-C-N)                                     (d) allene, H2CCCH2

Identify the main group to which X belongs in each of the following ionic compound formulas. (a) AlɔX3 (b) X(NO3)2 (c) CaX2

Covalent bonds are directional and “saturated”; ionic bonds are “unsaturated” and “non-directional”. (a) Explain why. (b) What are general consequences of the differences in the bonding characteristics?

Write the Lewis structures for the following, and include resonance structures where appropriate. Indicate which has the strongest carbon-oxygen bond.(a) CO2(b) CO

HCI VIO 4. Draw the Lewis structures for the following: (a) K (b) Cl (d) Ca2 (c) O2 nolar and which U he T0IIOWINO would you preo

Please don't use hend raiting and step by step solutions