Question 9: Waves Optics

Question

A tube of sugar solution $$20 \mathrm{~cm}$$ long is placed between crossed nicols and illuminated with light of wavelength $$6 	imes 10^{-5} \mathrm{~cm}$$. If the optical rotation produced is $$13^{\circ}$$ and the specific rotation is $$65^{\circ}$$, determine the strength of the solution.

Accepted Answer

The specific rotation < of a solution is
given
$$\alpha=\frac{	heta}{l 	imes c}$$
Where $$	heta$$ is the optical rotation in degrees, $$l$$ is the length of the tube in decimeter and $$c$$ the strength of the solution in $$\mathrm{gm} / \mathrm{cc}$$,
$$	herefore \quad c=\frac{	heta}{l 	imes \alpha}$$
Here $$	heta=13^{\circ}, l=20 \mathrm{~cm}=2 \cdot 0$$ decimeter and $$\alpha=65^{\circ}$$
$$	herefore c=\frac{13^{\circ}}{2 	imes 65^{\circ}}=0.1 \mathrm{~g} / \mathrm{cc}$$

Answer

0.1 g/cc

Answer

0.2 g/cc

Answer

0.9 g/cc

Answer

1.0 g/cc

Waves Optics

A tube of sugar solution $20 \mathrm{~cm} long is placed between crossed nicols and illuminated with light of wavelength 6 \times 10^{-5} \mathrm{~cm}. If the optical rotation produced is 13^{\circ} and the specific rotation is 65^{\circ}$, determine the strength of the solution.

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