Which of the following has the (R) configuration? a. t of CO₂H H₂N!! C CH₂OH H b. CO₂H H₂N H CH₂OH c. OH CH HO₂C CH₂OH O d. CH₂OH H+ OH CH3

Where is the positive charge in HeH+ located? Which atomic, orbitals contribute most to the bond energy in HeH+ ?

ii. Which one is stable, AlH3 or Al2H6 and why?

MCQ 155: The bond energy of the C=O bond is A. 350 kJ/mol B. 610k)/mol C. 360k]/mol D. 740kJ/mol

3. a. E,R is? b. E,S c. S,Z 4. What is the π-energy diagram of the compound in question 3? a. b. d. R,Z e. not a.-d. d. e. not a.-d.

10. Which element has the electron configuration 1s² 2s²2p³? C. S d. Cl 11. How many hydrogen atoms are connected to the indicated carbon atom? a. O b. F a. one b. two c. three 12. Which of the following is the correct condensed structure for the following compound? H H H H H H H H-C C -C C -C C C -H HC H H Br H H H H a. CH₂C(CH3)₂CH₂CH₂(CH)BrC(CH3)2 b. CH3CH₂CH3CCH₂CH₂C(CH3)2CHBr c. (CH3)3CCH₂CH₂CH₂BrCHCH3CH3 d. four e. none H 2 d. CH3CH₂CH₂CCH₂CH₂CHBrCHCH₂CH3 e. (CH3)3CCH₂CH₂CHBRCH(CH3)2

Resonance, hybridization, Lewis structures: Draw the most important resonance contributor of the butene-1 ion Draw the resonance form of the following structure. Interactive 3D display mode H₂C Draw the structure on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default. NN [1] A CH₂ H: 2D EXP. CONT L Marvin JS by ChemAxon H C N O S CI Br - P LL F

Choose the best Lewis.structure for CH₂Cl2.. O O H----H H-H---: H :d-c-a: H T- H Cl-C-Cl H H C=c=cr; H

Which of the following representations indicate the movement of an electron pair? CHз CH2 CH2 CH 23 =CH2 II. CH3 CH2 I. I. O a. || and II O b. || only O C. L Il and II O d.1only

H3C The structure of -NO₂ has a central nitrogen atom bonded to one oxygen atom by a sing double bond. The nitrogen atom carries a 1+ formal charge and the single bonded oxyger Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), toolbars, including charges where needed. The single bond is active by default. DOC -NO₂ Z [1] A HQ H2D EXP. CONT. L -O[1]-N[1] O H с N O S CI Br P F