Pka value caffeine citrate caffeine phosphate soft drinks?

[born2dive9702]

Ok if i understand my chemistry correct a hydroxide has a pKa value of 15.7 so that means it can form an "ionic bond"? with anything less than a pH of 15.7 i.e. phosphoric acid = 50/50 tri and di, Phosphate at 2. 148, 50/50 Di and mono @ ph7.199, 50/50 of mono and phosphate at ph 12.35

Now my investigation shows that caffeine is a base and has a pKa value of 14? is this correct?

Now from what I have read if you take caffeine and react it with citric acid you get caffeine citrate? is this correct? (when I mean react, i mean put the caffeine in water along with the citric acid then evaporate the water resulting in caffeine citrate)

Now here is my question, in a soft drink / carbonated beverage with a pH of say 2.51 would the caffeine be as caffeine, or as caffeine citrate? (my experience is the deprotonization of an acid (ie tri sodium phosphate to di sodium to mono...., )Not with the use of a base.

Next question if caffeine can form caffeine citrate, what is preventing caffeine from forming caffeine phosphate???

 

Please let me know.

[studiot]

22 minutes ago, born2dive9702 said:

Ok if i understand my chemistry correct a hydroxide has a pKa value of 15.7 so that means it can form an "ionic bond"? with anything less than a pH of 15.7 i.e. phosphoric acid = 50/50 tri and di, Phosphate at 2. 148, 50/50 Di and mono @ ph7.199, 50/50 of mono and phosphate at ph 12.35

Now my investigation shows that caffeine is a base and has a pKa value of 14? is this correct?

Now from what I have read if you take caffeine and react it with citric acid you get caffeine citrate? is this correct? (when I mean react, i mean put the caffeine in water along with the citric acid then evaporate the water resulting in caffeine citrate)

Now here is my question, in a soft drink / carbonated beverage with a pH of say 2.51 would the caffeine be as caffeine, or as caffeine citrate? (my experience is the deprotonization of an acid (ie tri sodium phosphate to di sodium to mono...., )Not with the use of a base.

Next question if caffeine can form caffeine citrate, what is preventing caffeine from forming caffeine phosphate???

 

Please let me know.

 

This would be a good place to start your research.

Read Chapter 10 in particular.

http://www.siirt.edu.tr/dosya/personel/mesrubat-ve-mesrubat-teknolojisi-ders-kitabi-siirt-2018221143430322.pdf

[John Cuthber]

I'm fairly sure that caffeine citrate is not a salt.

I think it's a hydrogen bonded molecular complex.