(Aldol, benzoin, +I, -I, decreases, increases, cyanohydrin, lactic acid, tartaric acid, yellow, white, acetone, penta-3-one, `PCl_(3)`, PCl, benzal chloride, methanol, propanoic acid, ethanol, KOH, KCN, `alpha`-hydrogen atoms, no `alpha`-hydrogens, Cannizzaro's, absence, presence)
Acetaldehyde in presence of NaOH gives ......... and this reaction is called ..........

Explanation

aldol,aldol condensation