A tube of sugar solution 20 cm long is placed between crossed nicols and illuminated with light of wavelength `6xx10^(-5)` cm If the optical rotation produced is `13^(@)` and the specific rotation is `65^(@)` determine the strength of the solution

Options

A. `0.1g//cc`
B. `0.2g//cc`
C. `0.9g//cc`
D. `1.0g//cc`

Answer

A

Explanation

The specific totation `alpha` of a solution is given by `alpha=(theta)/(lxxC)` where `theta` is the optical rotation in degrees, I is the length of the tube in dicimeter and c the strength of the solution in `gm//cc`
`therefore C=(theta)/(Ixxalpha)`
Here `theta =13^(@),I=20cm=2.0 decimeter and alpha=65^(@)`
`therefore c=(13^(@))/(2xx65^(@))=0.1g//cc`