1. All of the following are structural isomers of CH2=CHCH2CH=CHCH3 EXCEPT
a. CH2=CHCH2CH2CH=CH2
b. CH3CH=CHCH2CH=CH2
c. CH3CH=CHCH=CHCH3
d. CH2=C=CHCH2CH2CH3
Is it D?
2. Almost all of the amoino acids found in living organisms are in the L-form. L-Alanine and D-alanine are
a. structural isomers
b. geometric isomers
c. optical isomers
d. stereoisotopes
Is it C?
Thanks for helping out!
Isn't b just written the reverse of the original molecule? That makes it the same compound, not a different isomer.I think optical isomers is correct.
1. Yes, you are correct. The answer is D. CH2=C=CHCH2CH2CH3 is not a structural isomer of CH2=CHCH2CH=CHCH3.
2. No, you are not correct. The answer is C. L-Alanine and D-alanine are optical isomers.
To determine the correct answer to these questions, let's break them down and explain how to arrive at the answers.
1. For the first question, we need to identify which compound is NOT a structural isomer of CH2=CHCH2CH=CHCH3. Structural isomers have the same molecular formula but different structures. Let's analyze each option:
a. CH2=CHCH2CH2CH=CH2: This is a structural isomer as it has the same molecular formula but a different arrangement of atoms.
b. CH3CH=CHCH2CH=CH2: This is a structural isomer as well, as it has the same molecular formula but a different arrangement of atoms.
c. CH3CH=CHCH=CHCH3: This is a structural isomer as it has the same molecular formula but a different arrangement of atoms.
d. CH2=C=CHCH2CH2CH3: This compound does not have the same molecular formula as CH2=CHCH2CH=CHCH3, so it is not a structural isomer.
Therefore, the correct answer is d. CH2=C=CHCH2CH2CH3.
2. For the second question, we are asked to determine the relationship between L-alanine and D-alanine. Let's break down the options:
a. Structural isomers: Structural isomers have the same molecular formula but different structures. Since L-alanine and D-alanine have the same structure, they are not structural isomers.
b. Geometric isomers: Geometric isomers arise from the different configuration of double bonds. L-alanine and D-alanine do not have double bonds, so they are not geometric isomers.
c. Optical isomers: Optical isomers, also known as enantiomers, are mirror images of each other and differ in their ability to rotate plane-polarized light. L-Alanine and D-alanine are indeed optical isomers as they are mirror images of each other.
d. Stereoisotopes: The term "stereoisotopes" is not commonly used in organic chemistry and does not accurately describe the relationship between L-alanine and D-alanine.
Therefore, the correct answer is c. optical isomers.
I hope this helps clarify your questions! Let me know if you need further assistance.