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
- 28. Calculate the specific rotation of the following compound taken at 25°C using the sodium D line: 1g of sample is dissolved in 20mL of ethanol, the measurement was carried out in 20-cm polarimeter tube, and the observed rotation was equal to 1.25° counterclockwise. A -12.5° 29 Pradios B -22.5° C +12.5° D -0.25° с E -122.5° D F-36.0° G -1.25⁰arrow_forwardThe specific rotation, [a]p, for (-)-2-butanol is +14. What is the observed rotation for a solution of 3.3 g of (-)-2-butanol in 10 mL of water in a sample tube having a pathlength of 10 cm? degrees . The observed rotation of a solution of 0.75 g of a compound in 10 mL of water is -6.9 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound?arrow_forwardThe specific rotation, [a]p, for (-)-malic acid is -27. What is the observed rotation for a solution of 1.2 g of (-)-malic acid in 10 mL of water in a sample tube having a pathlength of 10 cm? | degrees. The observed rotation of a solution of 1.2 g of a compound in 10 mL of water is +0.75 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound? 9 more group attempts remaining Submit Answer Retry Entire Grouparrow_forward
- 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_forward2. The observed rotation of a compound, X (14.0g dissolved in water to make 100ml. of solution) in a polarimeter tube of length 30cm is +10.5°. What is the specific rotation of X?arrow_forward
- (R)-Camphor [a]20, = +44.0°/(g/mL)dm %3D A researcher places a 0.5 g/mL sample of camphor into a 1.0 dm cell and determines the observed rotation at 589 nm and 20 °C is +2.2°. What is the enantiomeric excess of (R)-camphor in the sample? 20% 95% 5% 10% 90% 80%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_forwardAn 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_forward
- Consider 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_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
- 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