Question

the specific rotation of a 10% sugar solution is 60 if the length of the polarimeter tube containing sugar solution is 20 cm the plane of polarization of light is rotated by

Answer 1

Final Answer : 12°

Steps:
1) We know,
$[\alpha]_{\lambda}^{T} = 60 \degree \:dm^{-1} mL g^{-1}$
length of tube, l = 2 dm
Concenntration ,C = 0.1 g/mL

Now,
$[\alpha]_{\lambda}^{T} = \frac{\alpha}{l * c} \\ => 60 = \frac{\alpha}{2*0.1} \\ => \alpha = 12 \degree$

Hence, Plane of Polarized light is rotated by +12° .

Answer 2

Answer: The plane of the polarized light is rotated by 12°.

Given:

$[\alpha] \lambda T = 60 dm^{-1} m Lg^{-1}$

Length of the tube = 20 cm = 20/10 = 2 dm

Concentration C = 10% = 10/100 = 0.1 g/ml

Solution:

We know that,

Specific rotation:

$[\alpha] \lambda T = \alpha / l \times C$

60 = $\alpha/ (2 \times 0.1)$

$\alpha = 60 \times 0.2 = 12$

= 12 degrees.