An attempt at synthesizing a certain optically active compound resulted in a mixture of its enantiomers. The mixture had an observed specific rotation of 14.1°. If it is known that the specific rotation of the R enantiomer is –28.4°, determine the percentage of each isomer in the mixture. g

The percentage of the R-enantiomer is 26.18% while the percentage of the S-enantiomer is 73.82%

Explanation:

If the specific rotation of R enantiomer = -28.4, then the specific rotation of S = +28.4

Now, let us have x = % R, thus

% S = 100-x =y

Hence;

{- 28.4x + 28.4( 100 -x)}/100= 14.1

Thus;

-28.4x + 2840 -28.4x = 1410

-56.8x + 2840 = 1410

-56.8x = 1410-2840

-56.8x = -1430

x = 1430/56.8

x = 26.18%

y = 100-26.18% = 73.82%

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.