Specific Rotation

When an optically active compound is placed in a 10 dm tube, it is present 20 gm in a 200 mL solution rotates the PPL by 30^o. Calculate the angle of rotation and specific angle of rotation if above solution diluted to 1 litre.

Dextrorotatory$$$\alpha \text{-}$pinene has a specific rotation ${\left[\alpha \right]}_{\text{D}}^{20}=+{\text{ 51.3}}^{\circ }$. A sample of $$$\alpha \text{-}$pinene containing both the enantiomers was found to have a specific rotation value ${\left[\alpha \right]}_{\text{D}}^{20}=+{\text{ 30.8}}^{\circ }$. The percentages of the (+) and (-) enantiomers present in the sample are, respectively.

Dextrorotatory$$$\alpha \text{-}$pinene has a specific rotation ${\left[\alpha \right]}_{\text{D}}^{20}=+{\text{ 51.3}}^{\circ }$. A sample of $$$\alpha \text{-}$pinene containing both the enantiomers was found to have a specific rotation value ${\left[\alpha \right]}_{\text{D}}^{20}=+{\text{ 30.8}}^{\circ }$. The percentages of the (+) and (-) enantiomers present in the sample are, respectively.

What is the specific rotation ${}^{20}[\alpha {]}_{\mathrm{D}}$ of the following molecule?

When a $300 \mathrm{m}\mathrm{m}$ long tube filled with $60 \mathrm{c}\mathrm{c}$ of sugar solution produces an optical rotation of $9^o,$ find the quantity of sugar in the solution ( $\alpha$ for sugar is $6^o{\mathrm{m}}^2/\mathrm{k}\mathrm{g}$ ).

1.2 gm of an optically active compound Cocaine $(\mathrm{\alpha }=\mathrm{ }-{16}^{\mathrm{o}})$ is dissolved in 7.5 ml of Chloroform. If the solution is kept in polarimeter of length 15 cm, then observed rotation is:

$\left(+\right)$ and $\left(-\right)$ forms of optically active compounds are different in