Compound A has a refractive index of 1.4577 at 20˚, while compound B (miscible with com- pound A) has a refractive index of 1.5000 at the same temperature.
(a) How could you experimentally determine if the refractive indexes of mixtures of A and B follow a linear relationship to the mole percent compositions of the mixtures?
(b) If the relationship is linear, what is the composition (in mole percent) of a mixture that has a refractive index of 1.4678 at 20˚C?

Question

Quizplus · Accepted Answer

The Answer is (a) Prepare several mixtures of A and B with known compositions. Determine their refractive indexes. Construct a graph of mol% versus nD and see if the points fall on the line joining 1.4577 (100%A) and 1.5000 (100%B).
(b) 76% A-24% B (from the graph not shown here)

Compound a Has a Refractive Index of 1