What are the chemical tests to distinguish between 2 pentanone and 3 pentanone?

Answer 1

Do an iodoform test. Use an aqueous solution of iodine and potassium iodide added to basic solutions of 2-pentanone and 3-pentanone.

The iodoform reaction is a classical test for methyl ketones. A light-yellow precipitate of iodoform forms immediately with the methyl ketone of 2-pentanone.

To confirm:

1H NMR

3-pentanone will show only 2 signals: a triplet at ~1.33 and a quartet at ~2.35

2-pentanone will show 4 signals: a triplet at ~0.90, a sextet at ~1.55, a singlet at ~2.05 and a triplet at ~2.40