A certain compound has a specific rotation of -43.2o (c = 5, toluene). What is the observed rotation of a sample of 1.24 g of the enantiomer of this compound when diluted to a concentration of 1.00 g ml-1 in the same solvent? Example 30 In his classic studies of stereochemistry and optical activity in organic compounds, Pasteur measured the optical activity of many solutions. For the naturally occurring enantiomer of tartaric acid, [α]D20 = +12.4o (c = 20, H2O). What can be concluded about the ratio of tartaric acid enantiomers present in the solution if the observed rotation is (i) α = -6.0o, or (ii) α = 0o?

A certain compound has a specific rotation of -43.2o (c = 5, toluene). What is the observed rotation of a sample of 1.24 g of the enantiomer of this compound when diluted to a concentration of 1.00 g ml-1 in the same solvent? Example 30 In his classic studies of stereochemistry and optical activity in organic compounds, Pasteur measured the optical activity of many solutions. For the naturally occurring enantiomer of tartaric acid, [α]D20 = +12.4o (c = 20, H2O). What can be concluded about the ratio of tartaric acid enantiomers present in the solution if the observed rotation is (i) α = -6.0o, or (ii) α = 0o?

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter3: Stereoisomerism And Chirality

Section: Chapter Questions

Problem 3.35P

See similar textbooks

Similar questions

The specific rotation (s) carvone (at 20°C) is +61. A chemist prepared a mixture of (R) carvone and its enantiomer, and this mixture had an observed rotation of -55. What is the specific rotation of (R)-carvone at 20°C?
Explain Biot's law and how it is determined with an example, calculate the specific rotation of a mixture of two enantiomers in unequal parts.
A 0.26 M solution of an enantiomerically pure chiral compound D has an observed rotation of +0.197° in a 1‑dm sample container. The molar mass of the compound is 132.3 g/mol. a. What is the specific rotation of D? b. What is the observed rotation if this solution is mixed with an equal volume of a solution that is 0.26 M in L, the enantiomer of D? c. What is the observed rotation if the solution of D is diluted with an equal volume of solvent?
An aqueous solution containing 10 g of an optically pure compound was diluted to 500 mL with water and was found to have a specific rotation of −121º. If this solution were mixed with 500 mL of a solution containing 3 g of a racemic mixture of the compound, what would the specific rotation of the resulting mixture of the compound? What would be its optical purity?
Pyrethrin II and pyrethrosin are two natural products isolated from plants of the chrysanthemum family. Pyrethrin II is a natural insecticide and is marketed as such. Q,) Label all chiral centers in each molecule and all carbon-carbon double bonds about which there is the possibility for cis,trans isomerism.
Glutamic acid is a naturally occurring amino acid and isthe precursor to the food additive MSG (monosodium glutamate)which can cause allergic reactions in some people. If naturally occurring L glutamic acid has a melting point of 205 C and an optical rotation of + 31.5, what is the melting point and optical rotation of its enantiomer?
A student isgiven a solution labeled only as 2,3-dihydroxybutane. She used the polarimeter to determine its optical rotation, and found that the solution was not optically active. Draw the absolute configuration of theisomer of 2,3-dihydroxybutane that would give zero optical rotation.
a) draw the newman projectjon between C3-C4 bond for all of the structures over 360 degrees of rotation. start with highest energy of conformation b) starting at 0 degrees draw a qualitative torsional energy plot as a function of degree of rotation
Glutamic acid is a naturally occurring amino acid and is the precursor to the food additive MSG (monosodium glutamate) which can cause allergic reactions in some people. If naturally occurring L glutamic acid has a melting point of 205 C and an optical rotation of + 31.5, what is the melting point and optical rotation of its enantiomer?
3,4-Dimethylpent-1-ene has the formula CH2“CH¬CH(CH3)¬CH(CH3)2. When pure (R)-3,4-dimethylpent-1-ene is treated with hydrogen over a platinum catalyst, the product is (S)-2,3-dimethylpentane. How useful is the (R) or (S) designation for predicting the sign of an optical rotation? Can you predict the sign of the rotation of the reactant? Of the product? (Hint from Juliet Capulet: “What’s in a name? That which we call a rose/By any other name would smell as sweet.”
The barrier of rotation for the C–C bond in bromoethane is 3.7 kcal/mol. We previously learned that an eclipsing C–H bond with another C–H is about 1 kcal/mol each. Based on this, what is the energy cost to eclipse a C–H bond with a C–Br bond?
Does methane contain a plane of symmetry?