Interpretation:
The specific rotation of the compound has to be calculated.
Concept introduction:
The pair of Enantiomers has different configurations.
Pair of enantiomers has different optical activity, which means if one will show levorotatory then the other will show dextrorotatory.
The direction and magnitude of rotation of plane-polarized light by an optically compound is measured by using polarimeter.
This rotation of polarized light is specific for a compound at specified temperature and wavelength, so it is called as Specific rotation of that compound.
Specific rotation of compound is calculated by,
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Organic Chemistry
- If a substance is known to have a specific rotation of +20.0 deg mL/g dm, what is the concentration (in g/mL) of a solution that would give an observed rotation of +10.0 degrees, if the path length of the sample tube was 1.00 dm? Can you do this problem in your head?arrow_forwardHow can we decide whether an observed rotation of a solution of an optically active compound is +170° and not actually -190°?arrow_forward1. When 0.247 g of monosodium glutamate (MSG) is dissolved in 10.0 mL of water and placed in a sample cell 10.0 cm in length, the observed rotation at 20°(using the D line of sodium) is +0.632°. Calculate the specific rotation of MSG. 2. When 0.095 g of cholesterol is dissolved in 1.00 mL of ether and placed in a sample cell 10.0 cm in length, the observed rotation at 20°C (using the D line of sodium) is -0.299°.Calculate the specific rotation of cholesterol.3. The specific rotation of L-dopa in water (at 15°C) is -39.5. A chemist prepared a mixture of L-dopa and its enantiomer, and this mixture had a specific rotation of -34. Calculate the % ee of this mixture. 4. The specific rotation of vitamin B7 in water (at 22°C) is +92. A chemist prepared a mixture of vitamin B7 and its enantiomer, and this mixture had a specific rotation of +18. Calculate the % ee of this mixture.arrow_forward
- 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?arrow_forwardConsider a solution that contains 84.0% R isomer and 16.0% S isomer. If the observed specific rotation of the mixture is −37.0°, what is the specific rotation of the pure R isomer? [a] = = Oarrow_forwardThe specific rotation for compound D is -8.5° dm 1(g/mL)-1, what is the specific rotation of compound E under the same conditions? [a] = -8.5° dm-1 (g/mL)-1 OH O он О он ОН D E -8.5° dm-1 (g/mL)-1 +8.5° dm-1 (g/mL)-1 0° dm-1 (g/mL)-1 not enough information is provided to determine a valuearrow_forward
- CH, CH, Q3: The specific rotation of L-alanine in water (at 25°C) is +2.8. A chemist prepared a mixture of L-alanine and its enantiomer, and 3.50 g of the mixture was dissolved in 10.0 mL of water. This solution was then placed in a sample cell with a pathlength of 10.0 cm and the observed rotation was +0.78. Calculate the % ee of the mixture.arrow_forwardThe specific rotation of S-Ibuprofen is +54.5o. Which direction would a mixture containing 80% S-Ibuprofen and 10% R-ibuprofen rotate plane polarized light? To the left or to the right?arrow_forwardThe observed rotation for 100 mL of an aqueous solution containing 50,00 g of sucrose, placed in a 1-decimeter sample tube, is +20°. What is the specific rotation of sucrose? a) + 40 d) - 0.4 b)-4 e) +20 c) + 0.4arrow_forward
- Calculation of Optical rotation.arrow_forwardThe specific rotation of vitamin C ( using the D line of sodium, at 20°C) is +24. Predict what the observed rotation would be for a solution containing 0.100 g of vitamin C dissolved in 10.0 ml of ethanol and placed in a sample cell with a length of 1dm.arrow_forwardThe specific rotation for (-)-methylphenidate is -38° mL g¹ dm¯1. Path length of the polarimeter is 1 dm. 1 You dissolve 0.5 g of a mixture of (-)-methylphenidate and its enantiomer in 4 mL of water. You place the sample into a polarimeter and the observed rotation is found to be -0.2°. What percent of the mixture is composed of (-)- methylphenidate? (Round your answer to the nearest whole percent.) The numerical values in this calculation will change with each attempt. Double check before submitting additional attempts. 17arrow_forward
- EBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENTOrganic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning