COMEDK2019PhysicsWave Optics
Specific rotation of sugar solution is 0.01 SI units. 200 kgm ⁻³ of impure sugar solution is taken in a polarimeter tube of length 0.25 ~m and an optical rotation of 0.4 rad is observed. The percentage of purity of sugar in the sample is
Options
- A80 %
- B89 %
- C11 %
- D20 %
Correct answer
A. 80 %
Step-by-step solution
Given, specific rotation of sugar solution, =0.01 units Length of polarimeter tube, l=0.25 ~m Optical rotation, =0.4 rad Concentration of solution, c= ? As we know, specific rotation = Optical rotation Length of tube Concentration of sol. aligned &= l c c &= l &= 0.4 0.01 0.25 &=160 ~kg / m ³ aligned Concentration of sugar solution =200 ~kg / m ⁻³ (given) Percentage impurity of sugar in the sample aligned &= 160 200 100 % &=80 % aligned