Quiz | Stereoisomers
What is the definition of a chiral compound?
A superimposable object on its mirror image
A molecule with a carbon atom with 4 different substituents
A molecule with a plan of symmetry
A non-superimposable object on its mirror image
A chiral molecule is a molecule that is not superimposable on its mirror image
Which of the following statements is incorrect?
The specific rotation of 2 diastereomers has a different absolute value
(+) in front of a chiral compound means that its absolute configuration is R
A racemic mixture of a chiral compound contains equal amount of (+) and (-) compound
The (+) and (-) stereoisomer of the same chiral compound will rotate polarized light equally but in opposite directions
(+) in front of a chiral compound means that its specific rotation [α]D is positive
When [α]D > 0°, the plane-polarized light is rotated clockwise ⇒ the solution is said to be dextrorotary
How many chiral centers does the 2,4-dibromo-1,1,4-trimethylcyclohexane have?
0
1
2
3 or +
Chiral center: atom connected to 4 different substituents
They are sometimes marked with an asterick
Which of the following compound is chiral?
1-bromobutane
2-bromobutane
2-bromo-2-methylbutane
3-bromopentane
2-bromobutane has 1 stereocenter ⇒ this molecule is chiral
The other molecules do not have a stereocenter ⇒ they are achiral
Which of the following compound is meso?
cis-1,3-dimethylcyclohexane
trans-1,3-dimethylcyclohexane
(+)-2-methylbutane
1-bromo-3-methylcyclohexane
cis-1,3-dimethylcyclohexane is a meso compound
A meso compound is a compound that contains stereocenters but is achiral. It has a plane of symmetry
What is the enantiomer of the (1S,3S)-1-bromo-3-methylcyclohexane?
(1S,3R)-1-bromo-3-methylcyclohexane
(1R,3S)-1-bromo-3-methylcyclohexane
(1R,3R)-1-bromo-3-methylcyclohexane
(1S,3S)-1-bromo-3-methylcyclohexane is not chiral
2 enantiomers have opposite configurations in all chirality centers