How do you distinguish the Propanal and propanone pairs of compound .

Explanation

Propanel and propanone
On idoform test propanone responds, but absence of `CH_(3)CO`-group in propanal `(CH_(3)CH_(2)CHO)` it does not respond.
`underset("Propanone")(CH_(3)CO CH_(3))+underset("Sodium hypoiodite")(3NaOI) underset("Heat")overset(NaOH, I_(2))to underset("(Yellow ppt. idoform)")(CHI_(3)darr) + underset("Sodium acetate")(CH_(3)COONa)+2NaOH`