Differentiation of formaldehyde from other higher aldehydes


Chemicals needed

formaldehyde solution 1%  GSGESUND.gif (476 Byte) Xn    R 40-43    S 23-37

fuchsin sulphuric acid  GSGESUND.gif (476 Byte) Xi    R 36/37/38    S 26-36

propanal GSLEICHT.gif (932 Byte) F GSGESUND.gif (476 Byte) Xi   R 11-36/37/38     S (2)-9-16-29

hydrochloric acid 7%

One can also use other higher aldehydes.


Equipment needed

2 test tubes


Test procedure


Disposal

The diluted mixtures can be discharged into the drainage.


Elucidation

to be possibly added


Photos

The color of formaldehyde (left) becomes more intense, that of propanal(right) pales.


Literature

derived from experiment 271, "Unterscheidung von Methanal (Formaldehyd) und Ethanal (Acetaldehyd)", p. 164, [1]