Uncovering Citric Acid's Chemical Composition and pH

AI Thread Summary
Citric acid is a solid compound, and its pH can only be determined in a solution of known concentration. Lemon juice contains about 5% citric acid, resulting in a pH range of 2 to 3, though this can vary based on the ripeness of the fruit. The discussion clarifies that "pure citric acid" is a misnomer since citric acid is not found in a pure liquid form in lemon juice. The pH of lemon juice is significant for assessing its acidity and ripeness, which was historically measured using early pH meters. Understanding the chemical composition and pH of citric acid is essential for research in organic medicinal massage oils.
rainbow-chick
Messages
3
Reaction score
0
[SOLVED] pH question...

i'm writing a research paper on the organic medicinal massage oils. i need to know the chemical composition of citric acid and it's pH. can anyone help me?
 
Physics news on Phys.org
rainbow-chick said:
i'm writing a research paper on the organic medicinal massage oils. i need to know the chemical composition of citric acid and it's pH. can anyone help me?

http://en.wikipedia.org/wiki/Citric_acid

CS
 
There is no such thing as "pH of an acid". However, there is such thing as "pH of solution of the acid of known concentration". If you don't know concentration you can't say anything about pH. At best you may list dissociation constants.


&
 
what i was really looking for was the pH of lemon juice i read somewhere that lemon juice was pure citric acid...?? sounds stupid now that i think about. sorry and thank you for your help!
 
rainbow-chick said:
what i was really looking for was the pH of lemon juice i read somewhere that lemon juice was pure citric acid...?? sounds stupid now that i think about. sorry and thank you for your help!

"Pure citric acid" ---- nonsense since citric acid itself is a solid. Lemon juice is a liquid, a solution which contains a few solutes including citric acid. (Condition assumed, room temperature. ) Good thinking on your next thought shown from your message.
 
symbolipoint said:
"Pure citric acid" ---- nonsense since citric acid itself is a solid. Lemon juice is a liquid, a solution which contains a few solutes including citric acid. (Condition assumed, room temperature. ) Good thinking on your next thought shown from your message.

well can anyone tell me the pH of lemon juice?
 
rainbow-chick said:
well can anyone tell me the pH of lemon juice?

Taken from Wikipedia (might want to double check credibility):

"Lemon juice is about 5% (approximately .030 moles/Liter) citric acid, which gives lemons a tart taste, and a pH of 2 to 3."
 
rainbow-chick said:
well can anyone tell me the pH of lemon juice?

No, because it varies, depending on the fruit ripeness. That's what the first commercially available pH meter (Beckman's Model G) was made for - to help assess lemon ripeness.


www.ph-meter.info
 

Similar threads

Chemistry How to take into account autoprotolysis in weak base solution?
Replies
8
Views
2K
Chemistry Comparing methods of computing pH at equivalence point in titration
Replies
4
Views
1K
Create Buffer: Sodium Citrate & Citric Acid
Replies
1
Views
2K
Chemistry How to calculate pH at equivalence point using this alternative?
Replies
7
Views
1K
Chemistry Moles of NaOH to Create Buffer Solution pH=6 in 0.42M Ethanoic Acid
Replies
3
Views
3K
Chemistry Understanding how to calculate pH of a buffer solution
Replies
2
Views
1K
Magnesium bisglycinate + citric acid = ?
Replies
3
Views
2K
Chemistry Solving pH Changes: Adding Acid to a Buffer or Water
Replies
16
Views
3K
Solve 5pH Solution from Citric Acid (1L)
Replies
1
Views
2K
Calculating the pH of a Buffer Solution
Replies
7
Views
3K

Hot Threads

Recent Insights

Back
Top