Bonus question What is the relationship between the following two molecules?

Which arrow(s) indicates chiral center(s) in the compound shown?

Which statement is correct concerning the relative stabilities of the two conformations, A and B, below?  

Identify the lowest energy conformation of butane as a Newman projection looking down the C2-C3 bond.

What is the appropriate IUPAC name for compound shown?

What is the correct order of the Cahn-Ingold-Prelog ranking of the following substituents as used in assigning R and S configurations of chiral centers? (higher ranking > lower ranking) ​ 1. −CH2OH 2. −CHO 3. −OCH3 4. −OCOCH3 ​

Bonus question Which are identical compounds?

Which of the following illustrates a correctly positioned equatorial OH?

What is the % ee of a sample of carvone that exhibits a specific rotation of −40, given that the specific rotation of (R)-carvone is −61?

Is the alkene on the left in the molecule below E, Z, or neither?