The molecular formula of citric acid is C 6 H 8 O 7. The chemical formula for citric acid is best shown by a diagram of its complete structural formula. This shows how the atoms are arranged in the molecule. Citric acid has three carboxyl or-COOH groups and is triprotic in nature.
In order to make tan you should mix white and brown. If you want to make the brown color yourself mix 2 parts of one primary color (like red) and 1 part of each of the other t â¦ wo (blue and yellow). The more white you use the lighter the shade of tan.
My preferred colors for mixing the full range of skin tones are: 1  Titanium white (with watercolor, the paper acts as the white) 2  Titanium buff. 3  Cadmium yellow (medium or dark)  Cadmium 1  red. Burnt sienna.  Raw 1  umber. Prussian 2  blue. Payne's grey (not essential, but  useful)