Home
Class 12
CHEMISTRY
Dextrororatory bytan-2-ol has a specific...

Dextrororatory bytan`-2-ol` has a specific rotation `[alpha]_(D)^(25) =+13.52^(@)`. A sample of butan`-2-ol` shows a specific rotation `[alpha]_(D)^(25)=+6.72^(@)`. Calculate the enantiomers excess (or optical purity) of the sample?

A

`60%`

B

`50%`

C

`70%`

D

`80%`

Text Solution

Verified by Experts

The correct Answer is:
B
`%` Enantiomeric excess (optical purity)
`=("observed specific rotaiton")/("specific rotation of the pure enantiomer") xx 100%`
`= (+6.76^(@))/(+13.52^(@)) xx 100%`
`= 50%`
Promotional Banner

Topper's Solved these Questions

  • STEREOCHEMISTRY

    R SHARMA|Exercise Follow-up Test 2|1 Videos

  • STEREOCHEMISTRY

    R SHARMA|Exercise Follow-up Test 3|1 Videos

  • STEREOCHEMISTRY

    R SHARMA|Exercise Follow-up Test 1|1 Videos

  • SOLUTIONS

    R SHARMA|Exercise ARCHIVES|42 Videos

  • SURFACE CHEMISTRY

    R SHARMA|Exercise Archives|18 Videos

Similar Questions

Explore conceptually related problems

Dextrororatory alpha- pinene has a specific rotation [alpha]_(D)^(20) =+51.3^(@) . A sample of alpha- pinene containing both the enantiomers was found to have a specific rotation value [alpha]_(D)^(20) =+30.8^(@) . The percentages of the (+) and (-) enantiomers present in the sample are, respectively,

D(+) Glucose has melting point 146^(@)C and specific rotation [alpha]_(C)6(25) is + 122^(@)C . Another D(+) Glucose has melting 150^(@) C and specific rotation [alpha]_(D)^(25) is + 18.7^(@)C . The two form have significantly different optical rotation but when an aqueous solution of either form is allowed to stand, it rotation changes. The specific rotation of one form decrease and rotation of other increases until both solution show the same value +52.7^(@) . The change in rotation towards an equilibrium value is called mutarotation. What percentage of beta -D-(+) glucopyrnsone found at equillibrium in the aqueous solution?

D(+) Glucose has melting point 146^(@)C and specific rotation [alpha]_(C)6(25) is + 122^(@)C . Another D(+) Glucose has melting 150^(@) C and specific rotation [alpha]_(D)^(25) is + 18.7^(@)C . The two form have significantly different optical rotation but when an aqueous solution of either form is allowed to stand, it rotation changes. The specific rotation of one form decrease and rotation of other increases until both solution show the same value +52.7^(@) . The change in rotation towards an equilibrium value is called mutarotation. For mannose the mutarotation can be shown in brief as follow:

D(+) Glucose has melting point 146^(@)C and specific rotation [alpha]_(C)6(25) is + 122^(@)C . Another D(+) Glucose has melting 150^(@) C and specific rotation [alpha]_(D)^(25) is + 18.7^(@)C . The two form have significantly different optical rotation but when an aqueous solution of either form is allowed to stand, it rotation changes. The specific rotation of one form decrease and rotation of other increases until both solution show the same value +52.7^(@) . The change in rotation towards an equilibrium value is called mutarotation. Mutarotation is characteristic feature of

(+)- Butan -2-ol has [alpha]_(D)^(20) =+13.9^(@) .a sample of butane 2-ol contianing both the enantiomers was found to have a specific rotation value of -3.5^(@) under similar conditions. The percentages of the (+) and (-) enantiomers present in the mixture are, respectively,

Pure (S)-2-butanol has a specific rotation of +13.52 degrees. A sample of 2-butanol prepared in the lab and purified by disillation has a calculated specific rotation of + 6.76 degrees. What can you conclude about the composition ?

R SHARMA-STEREOCHEMISTRY-Follow-up Test
  1. The process of separating a racemic mixture into optically pure (+) an...

    Text Solution

    |

  2. Enantiomers can be separated by means of

    Text Solution

    |

  3. Dextrororatory bytan-2-ol has a specific rotation [alpha](D)^(25) =+13...

    Text Solution

    |

  4. Dextrororatory alpha-pinene has a specific rotation [alpha](D)^(20) =+...

    Text Solution

    |

  5. The specific rotation of a pure enantiomers is +12^(@). What will be i...

    Text Solution

    |

  6. According to CIP sequence rule, the correct arrangement in order of de...

    Text Solution

    |

  7. Which of the following structures has the R-configuration at the chir...

    Text Solution

    |

  8. Which of the following structures has the S-configuration at the chira...

    Text Solution

    |

  9. Which of the following structures has the D-configuration

    Text Solution

    |

  10. Which of the following assignment of priorities is not correct?

    Text Solution

    |

  11. Which of the following ligands has the highest priority according to C...

    Text Solution

    |

  12. Which of the following designations are correct for the naturally occu...

    Text Solution

    |

  13. Consider the following structures (A),(B),(C ) and (D). ...

    Text Solution

    |

  14. The correct IUPAC name of is

    Text Solution

    |

  15. The interchange of two groups (Brand CH(3) at the chiral centre of the...

    Text Solution

    |

  16. Which of the following pairs of structures represent enantiomers?

    Text Solution

    |

  17. How many steroisomers are possible for 3-chloropentan2-ol?

    Text Solution

    |

  18. In the configuration the configuration at the chiral centres are

    Text Solution

    |

  19. How many steroisomers of butane-2,3-diol, CH(3)CH(OH)CH(OH)CH(3), ar...

    Text Solution

    |

  20. Which of the following compounds may posses a meso stereosiemer?

    Text Solution

    |