How will you prepare ethanol, propan-2-ol-and 2-methyl propane-2-ol from Grignard's reagent ?
Define optical activity. Explain optical activity of lactic acid.

Explanation

(a)
(b)
(ii) Optical activity : When plane polarised light is passed through a solution of certain organic substance like glucose lactice acid etc. The plane polarised light gets rotated through a certain angle. This property or phenomenon of certain organic substance to rotate the plane plarised light towards right or towards left is called optical activity.
(iii) Optical activity of lactiv acid :
`H-underset(("Latic acid"))underset(CH_(3))underset(|)overset(COOH)overset(|)(C^(**))-OH` cotains only one asymmetric carbon atom
The number of optically active isomers, possibel depends on number of asymmetrical carbon atom As `2^(n)` where n=no. of asymmetric carbon atom thus for lactic acid, n=1 thus two optical isomers possible.