The concentration of an organic compound in chloroform is 6.15 g per 100 mL of solution. A portion of this solution in a 5 cm polarimeter tube causes an observed rotation of -1.2° . What is the specific rotation of the compound?

Question

The concentration of an organic compound in chloroform is 6.15 g per 100 mL of solution. A portion of this solution in a 5 cm polarimeter tube causes an observed rotation of -1.2° . What is the specific rotation of the compound? (A) +12° (B) -3.9° (C) -39° (D) +61.5°

Tardigrade Admin · Accepted Answer

[α]=([α] text observed /l × C)=(-1.2/5 × (6.15)1000)=-39°

Q. The concentration of an organic compound in chloroform is $6.15 g$ per $100 m L$ of solution. A portion of this solution in a $5 c m$ polarimeter tube causes an observed rotation of $- 1. 2^{\circ} .$ What is the specific rotation of the compound?

$+ 1 2^{\circ}$

$- 3. 9^{\circ}$

$- 3 9^{\circ}$

$+ 61. 5^{\circ}$

$[α] = \frac{[ α ] _{observed}}{l \times C} = \frac{- 1.2}{5 \times \frac{6.15}{1000}} = - 3 9^{\circ}$

Q. The concentration of an organic compound in chloroform is 6.15g per 100mL of solution. A portion of this solution in a 5cm polarimeter tube causes an observed rotation of −1.2∘. What is the specific rotation of the compound?

+12∘

−3.9∘

−39∘

+61.5∘