Use the molar bond enthalpy data in the table to estimate the value of AHin for the equation C₂H₂(g) + HBr(g) → C₂H, Br(g) The bonding in the molecules is shown. +H-Br H- H H Br Bond O-H 0-0 C-O 0=0 C=0 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 CEN N-H N-N N=N NEN F-F CI-CI Br-Br H-H H-F H-Cl H-Br H-S S-S kJ - mol-1 890 390 159 418 945 155 243 192 435 565 431 368 364 225 4

When drawing the Lewis structure of the HCC13 molecule, the structure should represent a total of 26 valence electrons. What is the best description of the complete Lewis structure of the molecule? Select one: AH atom should be in the center with single bonds to each Cl atom and a double bond to the C atom. A Cl atom should be in the center with a single bond to the C atom and a single bond to the H atom. AC atom should be in the center with a double bond to the H atom and double bonds to each Cl atom. AC atom should be in the center with single bonds to each Cl atom and a single bond to the H atom.

The entropy change for a reaction is -21.0 J/K. If delta H is -10.0 kJ/mol, calculate Keg at 1000 C using the Gibbs Free Energy equation and its relationship to Keg. * T = •E - ABC T T T Arial 3 (12pt) 回i Path: Words:0

Are any of these valid Lewis structures?

Predict which bond in the following groups is the most ionic in character. Calculate ∆EN for each to check your predictions.  H–Cl, H–Br, H–F  Na–O, Li–O, K–O

Predict whether each of these 3 substituents owill be axial or equatorial: t-butyl- CH,CH3 CH3

Two possible Lewis structures for the cyanate ion are shown below, with formal charges (FC) calculated for each atom. One structure has carbon as the central atom and the other has a nitrogen as a central atom. By considering formal charges, which arrangement of atoms is the best, and therefore most likely structure for cyanate? FC: -1 0 0 FC: -1 +1 -1 |:0—C=N:1 STRUCTURE A STRUCTURE B Structure A Structure B Both are equally likely QUESTION 19 Two possible Lewis structures for the thiocyanate ion are shown below, with formal charges (FC) calculated for each atom. One structure has carbon as the central atom and the other has a nitrogen as a central atom. By considering formal charges, which arrangement of atoms is the best, and therefore most likely structure for thiocyanate? FC: 00-1 FC: -1 +1 -1 Ec: STRUCTURE A STRUCTURE B O Structure A Structure B

Use the bond energies from the table in the reference sheet to determine the approximate enthalpy change of the following reaction. H2(g) + Br2(g)  --> 2HBr(g) Group of answer choices -57 kJ/mol -114 kJ/mol -256 kJ/mol 256 kJ/mol

[References] The compound oxygen difluoride is quite reactive, giving oxygen and HF when treated with water: OF2(g) + H20(g)→ 0g) + 2HF(g) =-318 kJ ot Using bond energies, calculate the bond dissociation energy of the O-F bond in OF7. Average Bond Energies (kJ/mol) Single Bonds Multiple Bonds pt N-H 391 149 C=C 614 432 565 H-H 839 495 745 1072 607 418 941 pt H--F N-N 160 208 C=C N-F 272 |-Br 175 H-CI H-Br 427 363 295 N-CI N-Br C=0* C=D0 200 pt H-1 243 S-H 347 N-O 201 S-F 327 N=N N N 253 S-CI S-Br 467 413 347 305 358 C-H 146 218 C--C C--N C-O C--F C-CI C-Br O-O 891 C=N C-N S-S 266 190 203 O-F 615 0-CI 340 393 360 452 485 O-I 一 234 Si-Si 339 276 Si-H Si-C Si-O e F-F 154 253 240 259 F-CI F-Br Cl-CI C-S 237 239 218 193 Cl--Br Br--Br *C== O(in CO,) - 799 O-F bond dissociation energy: kJ mol Submit Answer Try Another Version 1 item attempt remaining nything %3D