CHEM213exam1S24_key

2. Avogadro does not "waste" his time drawing a Lewis structure before determining the shape of PF3. He thinks that the shape of PF3 must be trigonal planar because there are three fluorine atoms bonded to the central phosphorus atom. a. Draw the Lewis structure for PF3. b. Was Avogadro's answer for the shape of a PF3 molecule correct? Explain c. Why is it important to draw the Lewis structure for a molecule before identifying the shape of the molecule? 3. Draw the Lewis structure of ozone, O3. Describe why ozone has a bent shape instead of a linear shape.

How much energy (in kJ) is required to separate (break) one mole of H-H bonds? Bond Length (pm) Energy (kJ/mol) H-H 74 436 H-C 106.8 413 H-N 101.5 391 H-O 97.5 467 O A) +436 kJ B) -436 kJ O C) +74 kJ D) -74 kJ E) 106.8 kJ

Given the table of bond energies, which of the following is an accurate comparison of the energetics of breaking bonds? H-H 436 H-F 569 H-CI 432 H-Br 366 H-I 298 C-H 410 C-c 350 CIN 300 C10 350 C-F 450 CICI 330 C-Br 270 CII 240 Table of Average Bond Energies (kJ/mole) N-H 390 NIN 240 N-F 270 N CI 200 N-Br 240 N1O 200 O-H 460 O O 142 O -F 180 O -CI 200 220 ✓ F-F 157 F-Cl 251 F-Br 234 Cl-Cl Cl-Br 243 219 Br-Br 194 1-1 153 179 1-Br I-CI 208 280 1-F C=C C=0 CIN C=S 010 498 N=N 418 N=0 607 C C C=O C=N NEN 611 745 615 477 835 1077 891 941 It is harder to break a C-C single bond than a C=C double bond because breaking the single bond releases more energy. It is harder to break a C-C double bond than a C-C single bond because breaking the double bond requires more energy. It is harder to break a C-C single bond than a C=C double bond because breaking the single bond requires more energy. It is harder to break a C=C double bond than a C-C single bond because breaking the double bond releases…

Given the table of bond energies, which of the following is an accurate comparison of the energetics of breaking bonds? H-H 436 H-F 569 H-CI 432 H-Br 366 H-I 298 C-H 410 C-C 350 CIN 300 C10 350 C-F 450 C-Cl 330 C-Br 270 CII 240 Table of Average Bond Energies (kJ/mole) N-H 390 NIN 240 N-F 270 N_CI 200 N-Br 240 N1O 200 0 H 010 0-F O -CI O -1 460 142 180 200 220 Y F-F 157 F-Cl 251 F-Br 234 CI-CI 243 Cl-Br 219 Br-Br 1-1 1-Br I-CI I-F 194 153 179 208 280 C=C C=0 C=N C=S 010 N=N N=O C C C=O CEN NEN 611 745 615 477 498 418 607 835 1077 891 941 It is harder to break a C-C single bond than a C=C double bond because breaking the single bond releases more energy. It is harder to break a C-C double bond than a C-C single bond because breaking the double bond requires more energy. It is harder to break a C-C single bond than a C=C double bond because breaking the single bond requires more energy. It is harder to break a C=C double bond than a C-C single bond because breaking the double bond…

1. How can you tell if a compound is covalent? 2. What distinguishes a covalent bond from an ionic bond? 3. How do you know how many valence electrons an atom has? 4. What is electronegativity? Is electronegativity a property of atoms or bonds? 5. What is polarity? Is polarity a property of atoms or bonds? 6. Describe in detail the N-F bond in terms of the relevant electronegativities and polarities. 7. What does VSEPR stand for and how does it allow one to predict the shapes of covalent molecules?