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 is the sample is

Question

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 is the sample is (A) 80 % (B) 89 % (C) 11 % (D) 20 %

Tardigrade Admin · Accepted Answer

Specific rotation (α)=(θ/l c) ⇒ c=(θ/α l)=(0.4/0.01 × 0.25)=160 kg / m 3 Now percentage purity of sugar solution =(160/200) × 100=80 %

Q. Specific rotation of sugar solution is $0.01$ SI units. $200 k g m^{- 3}$ 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 is the sample is

$80%$

$89%$

$11%$

$20%$

Specific rotation
$(α) = \frac{θ}{l c}$
$\Rightarrow c = \frac{θ}{α l} = \frac{0.4}{0.01 \times 0.25} = 160 k g / m^{3}$
Now percentage purity of sugar solution
$= \frac{160}{200} \times 100 = 80%$

Q. Specific rotation of sugar solution is 0.01 SI units. 200kgm−3 of impure sugar solution is taken in a polarimeter tube of length 0.25m and an optical rotation of 0.4 rad is observed. The percentage of purity of sugar is the sample is

80%

89%

11%

20%