Question

A $300$mm long tube containing $60$cc of sugar solution produces a rotation of $9^o$ when placed in a polarimeter. If the specific rotation is ${60}^o$. Calculate the quantity of sugar contained in the solution.

Answer 1

$l=$ 300 mm $=$ path length $=300mm\times \frac{1dm}{100mm}=3dm$
$[\alpha {]}_{\lambda }^T=\frac{\alpha }{l\times C}$
${60}^o=\frac{9^o}{3dm\times C}$
The concentration
$C=0.05$ g/mL
Volume of sugar solution $=60$ cc $=60$ mL.
The quantity of sugar contained in the solution $=0.05g/mL\times 60mL=3g$