Question

the answers i circled are incorrect. can you give me all the correct answers and explain why?

2) Which of the statements below correctly describes an achiral molecule? A The molecule has a nonsuperimposable mirror image. cule exhibits optical activity when it interacts with plane-polarized light. C) The molecule has an enantiomer. D) The molecule might be a meso form. E) None of the above 3) Predict the specific rotation of the compound shown. CH нс 4 A) It is impossible to predict; it must be determined experimentally. KBYBecause both asymmetric centers are R, the compound is dextrorotatory. C) Because both asymmetric centers are S, the compound is levorotatory. D) Zero; the compound is achiral. E) Because this compound represents a racemic mixture, the compound is dextrorotatory. 4) Which of the following terms correctly describe(s) the structural relationship between cis-1,3- dimethylcyclopentane and trans-1,3-dimethylcyclopentane? (A) enantiomers B) diastereomers C) geometric isomers D) both A and C E) both B and C 5) What term describes the structural relationship between (2R 3R.4S)-2,3,4-trichloroheptane and (2R 3R 4R 2,3,4-trichloroheptane? A) not isomers Bp constitutional isomers C) enantiomers D) diastereomers E) conformers

Answer 1

2. Statement descride achiral molecule is D- Molecule might be a meso form. Because all first 3 statement related to chiral compoud and meso compounds are superimposable on its mirror image and are achiral.

3. This is cis-1,4-dimethyl cyclohexane and is achiral compound because it has plane of summetry. It will not show optical rotation and nither R & S chiral isomer nor racemic mixture, Hence correct statement is D- Zero, compound is achiral.

band - HC plane of symmetry CHH cis 1,4-Dimethyl cyclohexame

4. cis-1,3-dimethyl cyclopentane is chiral molecule with 2 chiral center (1R, 3S) configration while trans-1,3-dimethyl cyclopentane is also chiral molecule with 2 chiral center (1R , 3R). These are not enantiomers and geometric isomers hence the relationship between these 2 isomer is diastereomers and correct statement is B- diastereomers

Cis-1,3-dimethyl cyclopentane trans-1,3-dimethyl cyclopentane (1 R,3.5)-1,3-dimethylcyclopentane (1R 3R)-1,3-dimethylcyclopentane

5. (2R,3R,4S)-2,3,4-trichloroheptane and (2R,3R,4R)-2,3,4-trichloroheptane are chiral compound with 3 chiral centers in each. same as above case, these isomers have only difference in chirality of 4th carbon. Hence relationship between these 2 isomer is diastereomers and correct statement is D- diastereomers

(20,3R 4.5)-2,3,4-trichloroheptane (2R 3R 4R)-2,3,4-trichloroheptane