Problem 5.31 The amino acid (S)-alanine has the physical characteristics listed under the structure. a. What is the melting point of (R)-alanine? b. How does the melting point of a racemic mixture of (R)- and (S)-alanine compare to the melting point of (S)-alanine? c. What is the specific rotation of (R)-alanine, recorded under the same conditions as the reported rotation of (S)-alanine? d. What is the optical rotation of a racemic mixture of (R)- and (S)-alanine? e. Label each of the following as optically active or inactive: a solution of pure (S)- alanine; an equal mixture of (R)- and (S)-alanine; a solution that contains 75% (S)- and 25% (R)-alanine. HO, NH2 (S)-alanine [a] = +8.5 mp = 297 °C
Carbohydrates
Carbohydrates are the organic compounds that are obtained in foods and living matters in the shape of sugars, cellulose, and starch. The general formula of carbohydrates is Cn(H2O)2. The ratio of H and O present in carbohydrates is identical to water.
Starch
Starch is a polysaccharide carbohydrate that belongs to the category of polysaccharide carbohydrates.
Mutarotation
The rotation of a particular structure of the chiral compound because of the epimerization is called mutarotation. It is the repercussion of the ring chain tautomerism. In terms of glucose, this can be defined as the modification in the equilibrium of the α- and β- glucose anomers upon its dissolution in the solvent water. This process is usually seen in the chemistry of carbohydrates.
L Sugar
A chemical compound that is represented with a molecular formula C6H12O6 is called L-(-) sugar. At the carbon’s 5th position, the hydroxyl group is placed to the compound’s left and therefore the sugar is represented as L(-)-sugar. It is capable of rotating the polarized light’s plane in the direction anticlockwise. L isomers are one of the 2 isomers formed by the configurational stereochemistry of the carbohydrates.
![Problem 5.31
The amino acid (S)-alanine has the physical characteristics listed under the structure.
a. What is the melting point of (R)-alanine?
b. How does the melting point of a racemic mixture of (R)- and (S)-alanine compare to the
melting point of (S)-alanine?
c. What is the specific rotation of (R)-alanine, recorded under the same conditions as the
reported rotation of (S)-alanine?
d. What is the optical rotation of a racemic mixture of (R)- and (S)-alanine?
e. Label each of the following as optically active or inactive: a solution of pure (S)-
alanine; an equal mixture of (R)- and (S)-alanine; a solution that contains 75% (S)- and
25% (R)-alanine.
HO,
NH2
(S)-alanine
[a] = +8.5
mp = 297 °C](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F3be591f4-e3af-4d72-acec-f35cf7d37200%2F959c854c-c8d1-4199-a8a2-78565024384e%2F0szbtwc_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 1 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Organic Chemistry](https://www.bartleby.com/isbn_cover_images/9781305580350/9781305580350_smallCoverImage.gif)
![Introduction to General, Organic and Biochemistry](https://www.bartleby.com/isbn_cover_images/9781285869759/9781285869759_smallCoverImage.gif)
![Organic Chemistry](https://www.bartleby.com/isbn_cover_images/9781305080485/9781305080485_smallCoverImage.gif)
![Organic Chemistry](https://www.bartleby.com/isbn_cover_images/9781305580350/9781305580350_smallCoverImage.gif)
![Introduction to General, Organic and Biochemistry](https://www.bartleby.com/isbn_cover_images/9781285869759/9781285869759_smallCoverImage.gif)
![Organic Chemistry](https://www.bartleby.com/isbn_cover_images/9781305080485/9781305080485_smallCoverImage.gif)
![Chemistry for Today: General, Organic, and Bioche…](https://www.bartleby.com/isbn_cover_images/9781305960060/9781305960060_smallCoverImage.gif)
![Chemistry: Principles and Practice](https://www.bartleby.com/isbn_cover_images/9780534420123/9780534420123_smallCoverImage.gif)