Answer. Acetylene is oxidized by alkaline KMn04. Hydroxyl groups add to the triple bond to form an intermediate product.
HC≡CH + 2KMnO4 + 2H20 OH OH + 2MnO2 + 2KOH
H-C—C-H
OH OH
O O
OH OH -2H2O ║ ║
H-C—C-H H-C-C-H
OH OH Glyoxal
This intermediate product eliminates water molecules to from glyoxal, which on oxidation forms oxalic acid
O O 2[O] O O
OH OH -2H2O ║ ║ KMnO4 ║ ║
H-C—C-H H-C-C-H HO-C-C-OH
OH OH Glyoxal Oxalic acid
This reaction is also used to test the unsaturation in an organic compound.