Xanthoproteic Test To 2 mL of sample add 1 mL concentrated HNO3. Observe whether a heavy white precipitate is formed. Heat carefully and observe whether the precipitate turns yellow and finally dissolves. Record the color of the precipitate and/or the solution. Cool and make alkaline with 10% NaOH. Record the color. Question 1. What do you think was the white precipitate formed after the addition of nitric acid and why did it turn to yellow after heating? Question 2. Why did the mixture change in color after addition of 10% NaOH? Question 3. Will it give positive test to all the proteins?

Xanthoproteic Test To 2 mL of sample add 1 mL concentrated HNO3. Observe whether a heavy white precipitate is formed. Heat carefully and observe whether the precipitate turns yellow and finally dissolves. Record the color of the precipitate and/or the solution. Cool and make alkaline with 10% NaOH. Record the color. Question 1. What do you think was the white precipitate formed after the addition of nitric acid and why did it turn to yellow after heating? Question 2. Why did the mixture change in color after addition of 10% NaOH? Question 3. Will it give positive test to all the proteins?

Chemistry & Chemical Reactivity

9th Edition

ISBN:9781133949640

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter17: Principles Of Chemical Reactivity: Other Aspects Of Aqueous Equilibria

Section17.3: Acid-base Titrations

Problem 3RC

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