(a) Using Newman projections, draw all staggered and eclipsed conformations that result from rotation around the bond highlighted in red in each molecule; (b) draw a graph of energy versus dihedral angle for rotation around this bond. [2]

Problem (#2.) For each ion below, draw all reasonable resonance structures (linked by resonance arrows “↔”). Include curved arrows that indicate the movement of electrons between each resonance structure. Assign non-zero formal charges to each atom for each resonance structure. (a.) NO3–  (nitrate) (b.) CH3COO– (acetate) (c.) N3– (azide) (d.) NCO– (isocyanate) Problem (#3.) For each ion in question 2, draw a resonance hybrid, assigning non-zero formal and/or partial charges (δ+, δ–) as needed. Problem (#4.) For each skeletal structure below, satisfy the valences (or octets) of all of the atoms by filling in double and triple bonds as well as unshared electron pairs. Assign non-zero formal charges and show the overall charge if the structure is an ion. See photo attached for Problem number 4.   Problem (#5.) For each structure in question 4, draw a resonance hybrid (if it has one) and assign non-zero formal and/or partial charges as needed.

add one double‑barbed curved arrow to each structure to show the delocalization of the electron pair to form the next structure

Draw and name a constitutional isomer that has two stereocenters and is named a“....tetramethylhexane”.

a) Draw one isomer of C6H14. b) Draw one isomer of C6H12- c) Draw one isomer of C6H140 that exhibits hydrogen bonding. d) Draw one isomer of C6H140 that is not capable of hydrogen bonding. BONUS: Show all locations of possible hydrogen bonding for the C6H140 isomer that you drew above in part c.

1.) Circle the localized lone pairs and box the delocalized lone pairs:

The instructions are to draw the resonance hybrid structure of the molecule on the left. My answer is circled , which is wrong. Can someone explain why?