Concentation of Citric Acid in Fruit Juice

In summary, the juice substance is Tang and the solution of juice is prepared by dissolving 4.00 grams of crystals in 100.0 mL of solution. A solution of juice is then titrated using a given solution of sodium hydroxide. Phenolphthalein is used as an indicator. Trial # NaOH(aq) added (mL) Trial 1 3.31 Trial 2 3.18 Trial 3 3.27
  • #1
Gurvir
19
0

Homework Statement


This is a lab for Chemistry in grade 12.

I'll give some basic info I have.

Juice substance is Tang.
A solution of juice is prepared by dissolving 4.00 grams of crystals in 100.0 mL of solution. The juice solution is then titrated using a given solution of sodium hydroxide. Phenolphthalein is used as an indicator.

Here is my observations,

Trial # NaOH(aq) added (mL)
Trial 1 3.31
Trial 2 3.18
Trial 3 3.27

Homework Equations


a) find mol/L of acid (I can do this but I cannot figure out the balanced equation)
b) how many grams of pure citric acid is in 100 g of tang (as a percent mass)
*Citric Acid is in your databook. Assume it loses 3 hydrogens.
My teacher said you shouldn't need the formula of the Tang

The Attempt at a Solution



This is all I can think of, I do not know what it will turn into.

C3H5O(COOH)3(aq) + NaOH(aq) ==>
 
Last edited:
Physics news on Phys.org
  • #3
Borek said:
You are on the right track.

http://www.titrations.info/titration-calculation

I think I understand it more now!

Let me see,

C3H5O(COOH)3(aq) + 3 NaOH(aq) ==> C3H5O(COO)3(aq) + 3 H2O(l) + 3 Na(s)

But there wasn't any solid from the reaction so I'm not sure where the Na(s) goes, does it just separate or get added onto one for the formula's?
 
Last edited:
  • #4
No no, that was completely wrong. Your product will be a sodium salt!
 
Last edited by a moderator:
  • #5
Borek said:
No no, that was completely wrong. Your product will be a sodium salt!

--
buffer calculator, concentration calculator
pH calculator, stoichiometry calculator

What? Now I'm confused again, how does that work? Please tell me asap, I don't have long until I have to have this lab complete.

Why would it be NaCl? That doesn't make sense with anything. Cl wasn't even part of the experiment. It can't be created through thin air.

C3H5O(COOH)3(aq) + 3 NaOH(aq) ==> C3H5O(COO)3(aq) + 3 H2O(l) + 3 Na(s)

This makes sense to me, I don't know where NaCl would go.
 
Last edited:
  • #6
A salt in chemistry isn't necessarily table salt (NaCl) but an ionic compound you get, along with water, after the neutralization of an acid and [STRIKE]salt[/STRIKE] base.

You wouldn't actually have C3H5O(COO)3(aq) and Na(s), but rather C3H5O(COO)33-(aq) and Na+(aq). The first one ionized since it lost H+ ions while the Na is still an Na+ ion. It could also be written as Na3C3H5O(COO)3(aq)
 
Last edited:
  • #7
Bohrok already nicely explained what is going on. Salt name is sodium citrate.
 
Last edited by a moderator:

What is citric acid and why is it important to measure its concentration in fruit juice?

Citric acid is a natural compound found in many fruits, especially citrus fruits. It is important to measure its concentration in fruit juice because it affects the taste, acidity, and preservation of the juice. It is also used as a preservative and flavoring agent in many food and beverage products.

How is the concentration of citric acid in fruit juice typically measured?

The most common method for measuring the concentration of citric acid in fruit juice is through titration. This involves adding a known amount of a base solution to the juice until the citric acid is neutralized. The amount of base solution needed to neutralize the citric acid can then be used to calculate the concentration of citric acid in the juice.

What factors can affect the concentration of citric acid in fruit juice?

The concentration of citric acid in fruit juice can be affected by various factors such as the type of fruit, ripeness of the fruit, and storage conditions. The amount of citric acid can also vary depending on the variety of the fruit and the processing methods used to make the juice.

Why is it important to accurately measure the concentration of citric acid in fruit juice?

Accurate measurement of citric acid concentration is important for maintaining consistent flavor and quality of fruit juice. It is also necessary for ensuring the safety of the product, as high levels of citric acid can be harmful to some individuals. Additionally, accurate measurement allows for proper labeling and nutritional information for consumers.

What are some common sources of error when measuring the concentration of citric acid in fruit juice?

Some common sources of error when measuring citric acid concentration in fruit juice include inaccurate measurements, improper calibration of equipment, and contamination from other substances. It is also important to ensure that the sample being tested is representative of the entire batch of fruit juice.

Similar threads

What is the right amount of citric acid and sodiumhypophosphite?
    • Biology and Chemistry Homework Help
Replies
2
Views
2K
Create Buffer: Sodium Citrate & Citric Acid
    • Biology and Chemistry Homework Help
Replies
1
Views
1K
Calculating the Neutralization of Acid in Grapefruit Juice
    • Biology and Chemistry Homework Help
Replies
2
Views
4K
Ascorbic Acid Amount Calculation (stoichiometry/)
    • Biology and Chemistry Homework Help
Replies
4
Views
38K
At what temperature does citric acid decay?
    • Chemistry
Replies
5
Views
3K
Acetylsalicylic Acid Titration Lab: Calculating Mass and Moles of Aspirin
    • Biology and Chemistry Homework Help
Replies
2
Views
3K
Solving for Grams of Citric Acid in Juice Solution
    • Biology and Chemistry Homework Help
Replies
12
Views
9K
Acid-Base Titration Problems
    • Biology and Chemistry Homework Help
Replies
4
Views
3K
Neutralization by Acid-Base Titration Problems HELP
    • Biology and Chemistry Homework Help
Replies
1
Views
9K
What is the Percent Oxalic Acid Dihydrate in an Unknown Sample?
    • Biology and Chemistry Homework Help
Replies
5
Views
4K

Hot Threads

Recent Insights

Back
Top