The specific rotation, [α]D, for (-)-2-butanol is +14. What is the observed rotation for a solution...

The specific rotation, [α]D, for (-)-2-butanol is +14. What is the observed rotation for a solution of 1.0 g of (-)-2-butanol in 10 mL of water in a sample tube having a pathlength of 10 cm? ??????degrees .

The observed rotation of a solution of 1.5 g of a compound in 10 mL of water is +3.4 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound? .

Expert Solution

[α]_l^T = α/lc

α = observed rotation in degrees.
l = cell path length in decimeters. (1 decimeter = 1 dm = 10 cm. A standard polarimeter tube is 1.00 dm in length.)
c = concentration in g ml^-1 for a pure liquid compound (i.e., the liquid's density), or g 100 ml^-1 for a solution.

The specific rotation, [α]D, for (-)-2-butanol is +14. What is the observed rotation for a solution of 1.0 g of (-)-2-butanol in 10 mL of water in a sample tube having a pathlength of 10 cm?

observed rotation = 14 x 10 x 1 = +140 degrees

The observed rotation of a solution of 1.3 g of a compound in 10 mL of water is +8.2 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound?

specific rotation = 8.2 / 1 x 13 = +0.63 degrees

The specific rotation, [α]_D, for (-)-2-butanol is +14. What is the observed rotation for a solution of 2.5 g of(-)-2-butanol in 10 mL of water in a sample tube having a pathlength of 10 cm?

observed rotation = 14 x 25 x 1 = +350 degrees

The observed rotation of a solution of 1.4 g of a compound in 10 mL of water is +13 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound?

specific rotation = 13 / 1 x 14 = +0.928 degree

The specific rotation, [α]_D, for (-)-malic acid is -27. What is the observed rotation for a solution of 0.50 g of(-)-malic acid in 10 mL of water in a sample tube having a pathlength of 10 cm?

observed rotation = -27 x 5 x 1 = -135 degrees

The observed rotation of a solution of 0.66 g of a compound in 10 mL of water is -5.3 degrees. If the pathlength is 10 cm, what is the specific rotation of the compound?

specific rotation = -5.3 / 1 x 6.6 = +0.803 degree

queen_honey_blossom answered 2 years ago

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