Oxidation of organic compounds with chromic acid

Chemicals necessary

acetone GSLEICHT.gif (932 Byte) F   R 11    S (2)-9-16-23-33

distilled water

ethanol GSLEICHT.gif (932 Byte) F    R 11    S (2)-7-16

or denatured alcohol

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

sulphuric acid potassium dichromate solution GSGiftig.gif (734 Byte) T+ GSATZEND.gif (935 Byte) C GSUMWELT.gif (758 Byte)  N    R 21-25-26-35-37/38-41-43-46-49-50/53    S (1/2)-26-45-53-60-61

Other alcohols, aldehyes and ketones can be used. Diluted chromosulphuric acid can also be used.

Equipment necessary

3 test tubes
test tube rack
burner (if possible alcohol-)

Test procedure


All solutions are disposed of as heavy metal waste.


The yellow/orange Cr(VI) is in a acidic solution (in the form of chromic acid), especially when warm, a strong oxidant and is reduced to a green Cr(III). Similiarly alcohol and aldehyde are oxidized to carboxylic acid respectively. In the case of aceton a comparable transformation is not possible.


DSCN0217.JPG (195232 Byte)

Ethanol (left) und propanal (middle) reduced Cr(VI), acetone (right) not.


Own procedure modelled after a school experiment.