Question

Sucrose on hydrolysis yields a mixture which is

• A. Optically inactive
• B. Dextrorotatory
• C. Laevorotatory
• D. Racemic

Answer 1

The correct option is C Laevorotatory

$\begin{array}{ccccc}Sucrose& \to & Glucose& +& Fructose\\ +{65}^o& & +{52.5}^o& & -{92.4}^o\end{array}$
On hydrolysis of sucrose $d-glucose$ and $l-fructose$ are formed whose specific rotaion are $+{52.5}^{\circ }and-{92.4}^{\circ }$ respectively. So, the specific rotation of the product mixture is $\frac{1}{2}\times {39.9}^o={19.95}^o$ that is overall negative and becomes laevorotatory.