21 Which statement is correct concerning the relative stabilities of the two conformations, A and B, below? CH₂ H₂C- H A H CH₂ Multiple Choice A is more stable. B is more stable. A and B are equal in stabilities. H B CH₂ A and B are not equal in stability, but the preferred conformation cannot be determined by inspection.

Draw a perspective representation of the most stable conformation of 3-methylhexane. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds and charges), Atoms, and Templates toolbars. 0 + 7 C Akri C H 12D EXP CONT Marvin JS by ChemAxon 1 H CI P UNOS J

Which of the shown dibromocyclohexanes are constitutional isomers? Br Br CI Br ČI Br ČI Br C 1 and 4 O1. 2 and 4 2. 2 and 3 O 3. 4. 1 and 3 1 and 2 5.

Identify the correct chair conformations of the following compound and then indicate which one is more stable. OH OH OH HO 1 || 4 OI and II are correct chair structures and I is most stable OI and II are correct chair structures and II is most stable OI and III are correct chair structures and III is most stable O II and III are correct chair structures and II is most stable O II and III are correct chair structures and III is most stable |||

4 Practice 2 3-9 4.8 Conformational Analysis of Butane The graph below represents the relative energies of the conformations of butane: ww B Relative energy -1- —— 0° 60° 120° 180° 240° 300° 360° Angle of rotation Select the Newman projection that corresponds with position C on the graph (an angle of rotation of 120 degrees). HA 3 H I I I I # CH3 CH 3 CH 3 CH3 -I H HH CH3 CH3 CH3 80⁰0 CH3 H I I Н 4 000 000 % 6 MacBook Air 7 8 DIL FB 9 0