Question

1. The height of three peaks; A, B, and C obtained in a gas chromatogram are 27.7 mm, 19.2 mm and 41.0 mm. The width of the peaks, at half height, are 4.9 mm, 4.7 mm and 4.6 mm, respectively.

2.The optical purity of (+)-glucose in a mixture of (+) and (-)-glucose is 72%. What is the percentage of (+)-glucose in the sample?

3.Calculate the specific rotation, [α], if the observed rotation is -24°, the concentration is 0.4 g/mL, and the cell length is 5 cm. Answer in mL/g/dm

Answer 1

1. Nothing mentioned to answer Pure (+) ghecose present in the mixture is 72% So, Mixture of (t) and (-) - glucose is (100-72)% = 28% the So, the percentage of (+)- glucose in sample is (72 + 28% = 86/ 13/ Observed rotation, a = -240 concentration, c = 0.4 g/mL cell length , 1=5cm = 0.5 dm Now, specific rotation, [a] = x cil - 249 0.4 g/mL x 0.5 dm. = – 120° mL/g/dm so, the specific rotation, [x], is – 120 mL/g/dm