Question

5.60g of glyceraldehydes was dissolved in 10ml of a solvent and placed in a 50mm cell if the rotation is 1.74 calculate the specific rotation?​

Answer 1

Answer:

6.214 degrees-mL/gdm

Explanation:

The specific rotation α' = α/LC where α = observed rotation, L = length of tube and C = concentration of solution.

Given that α = 1.74, L = length of cell = 50 mm = 0.50 dm and C = m/V where m = mass of glyceraldehyde = 5.60 g and V = volume = 10 ml

So, C = m/V = 5.60 g/10 ml = 0.560 g/ml

Since α' = α/LC

substituting the values of the variables into the equation, we have

α' = α/LC

α' = 1.74/(0.50 dm × 0.560 g/ml)

α' = 1.74/(0.28 gdm/l)

α' = 0.006214 °mL/gdm

α' = 6.214 °mL/gdm

α' = 6.214 degrees-mL/gdm