AP and TS EAMCET Engineering Model Paper 3

The aqueous solution of sucrose is dextrorotatory having [α]D=66.4°. On hydrolysis with dilute acids or enzyme invertase, cane sugar (sucrose) gives equimolar mixture of D−(+)− glucose and D−(−)− fructose

So, sucrose is dextrorotatory but after hydrolysis gives dextrorotatory glucose and laevoratatory fructose. D−(−)−fructose has a greater specific rotation than D−(+)− glucose. Therefore, the resultant solution is laevoratatory in nature with specific rotation of −39.9° .