Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Give the axis of symmetry (AOS) of each of the following compounds, in the order listed :
(1) cyclopentadienyl anion
(2) benzene
(3) H2O
(4) cyclopropane
(5) cyclobutane
(6) H-Cl
(7) CH2=CFCl
(8) 2,3-dichlorobutane (Fischer projection)
(9) 1,5-dibromonaphthalene
(10) PF5
(11) CO2
(12) allene (H2C=C=CH2)
(13) 1H-phenalene
(14) N(CH3)3
Options:
Answer:
Solution:
Cyclopentadienyl anion : C5. Benzene : C6. H2O : C2. Cyclopropane : C3. Cyclobutane : C4. H-Cl : C∞ (any rotation about the bond axis). CH2=CFCl : AOS absent. 2,3-Dichlorobutane (Fischer projection) : C2. 1,5-Dibromonaphthalene : C2 (the diagonal through the two Br-bearing carbons). PF5 : C2. CO2 : C∞ along the molecular axis, and a C2 axis perpendicular to it through C. Allene, H2C=C=CH2 : C2 along the C=C=C chain. 1H-Phenalene : C3. N(CH3)3 : C3.
