Question

Need help with orgo!!! Super badly!

1. Which of the molecules shown below are achiral?

A) only A
B) only B
C) only C
D) only A and B
E) only A and C
F) only B and C
G) A, B and C

2. Which of the molecules shown below are achiral?

A) only A
B) only B
C) only C
D) only A and B
E) only A and C
F) only B and C
G) A, B and C

3. What is the relationship between the two molecules shown below?

A) They are constitutional isomers.
B) They are enantiomers.
C) They are identical.
D) They are diastereomers.

4. What is the relationship between the two molecules shown below?

A) They are diastereomers.
B) They are enantiomers.
C) They are constitutional isomers.
D) They are identical.

5. Which of the molecules shown below are chiral?

A) only A
B) only B
C) only C
D) only A and B
E) only A and C
F) only B and C
G) A, B and C

6. Which compound is a diastereomer of (R)-4-bromo-cis-2-hexene?

A) (S)-5-bromo-trans-2-hexene
B) (S)-4-bromo-cis-2-hexene
C) (R)-4-bromo-trans-2-hexene
D) (R)-5-bromo-cis-2-hexene

7. What is the configuration of each molecule shown below?

A) Both molecules have the R configuration.
B) Both molecules have the S configuration.
C) Molecule A has the R configuration and molecule B has the S configuration.
D) Molecule A has the S configuration and molecule B has the R configuration.

Answer 1

1 ) answer : F) only B and C

reason : A is optical active compound with two chiral centers.

but both B and C are optical inactive eventhough having two chairal centers in each. it is due to plane of symmetry in both compounds. so B and C are achairal

2) answer : A) only A

there are no chairal centers present in A . so it is achairal

but in B and C one chiaral center is present at each compound. so those two are chairals.

3) answer : B) They are enantiomers.

they are just mirror images to each other. one is rotates plane polarised light to left and other one rotates to right.

4) answer : A) They are diastereomers.

first compound is meso compound and second one is either d or l . meso + d/l combinations are not mirror images and not super impossible . so these two are diasteromers.

5) answer : G) A, B and C

all are option active compounds.

6)   ansewr : C) (R)-4-bromo-trans-2-hexene

cis and trans are diastereomers to each other

7) answer : D) Molecule A has the S configuration and molecule B has the R configuration.