Ask a New Question
Menu

Which of the following would be ranked as the lowest priority group?

Group of answer choices

-PO3

-CH2Cl

-NH2

-OH

3 answers

To determine the lowest priority group using the Cahn-Ingold-Prelog priority rules for assigning priorities, we need to compare the groups based on the atomic numbers of the atoms directly bonded to the chiral center.

  1. PO3 (phosphate): The phosphorus (P) in PO3 is bonded to three oxygen atoms (atomic number 8) and can be considered to have a higher priority due to the presence of phosphorus.

  2. CH2Cl (chloromethyl): The carbon (C) in CH2Cl is bonded to hydrogen (H) (atomic number 1) and chlorine (Cl) (atomic number 17). Since Cl has a higher atomic number than both H and C, CH2Cl is ranked fairly high.

  3. NH2 (amino): The nitrogen (N) in NH2 is bonded to hydrogen atoms. Nitrogen has an atomic number of 7, which gives it a moderate priority.

  4. OH (hydroxyl): The oxygen (O) in OH has an atomic number of 8. However, it is directly bonded to hydrogen, which has the lowest atomic number among the groups being considered.

Now we can assign priorities based on the atomic numbers of the first atoms directly bonded to the chiral center:

  • PO3 (P)
  • OH (O)
  • NH2 (N)
  • CH2Cl (Cl)

The group NH2 would likely be ranked as the lowest priority group because nitrogen has a lower atomic number than both phosphorus and oxygen, and overall, NH2 tends to be lower in priority than the others when compared.

Thus, the answer is:

-NH2

Thats not the right answer. So what is the right answer?

To rank the groups based on Cahn-Ingold-Prelog priority rules, we should examine the atoms directly bonded to the first atom of each group.

  1. PO3 (phosphate) - phosphorus (P) is bonded to three oxygen atoms (O). Phosphorus has an atomic number of 15.
  2. CH2Cl (chloromethyl) - carbon (C) (atomic number 6) is bonded to hydrogen (H) (atomic number 1) and chlorine (Cl) (atomic number 17). The presence of chlorine gives it a higher ranking.
  3. NH2 (amino) - nitrogen (N) (atomic number 7) is bonded to two hydrogens (H).
  4. OH (hydroxyl) - oxygen (O) (atomic number 8) is bonded to hydrogen (H).

Now, Let's evaluate them based on the first atoms in each group:

  1. PO3 - P (atomic #15)
  2. CH2Cl - Cl (atomic #17)
  3. NH2 - N (atomic #7)
  4. OH - O (atomic #8)

Since we are looking for the lowest priority, we see that NH2 has the lowest atomic number of the first atoms. However, it appears I made an error in evaluating the priority combinations.

Given that the group CH2Cl contains chlorine (Cl) which is higher than the other groups, and considering NH2 is typically lower than OH, the lowest priority group should be based more precisely.

The lowest priority group should actually be:

-CH2Cl

Therefore the correct answer for the lowest priority group is CH2Cl. Thank you for your patience, and I apologize for the confusion earlier.