I really need help in how to work out the solutions for these questions. I want
ID: 51598 • Letter: I
Question
I really need help in how to work out the solutions for these questions. I want to work them out but just have not idea how.
Assume that you have collected 40 ml egg white. Answer the following questions:
a) How much 1.0 N Acetic acid will be added to the above egg white? What is the purpose of adding acetic acid? Explain briefly.
b) What will be the pH of the egg white solution after adding 1 N acetic acid, assuming egg white is neutral?
c) Which salt would you use for this experiment? Why this salt is useful compared to other salts?
d) Which three major proteins are found in egg white? Out of these three proteins, which protein requires lower ionic strength and higher ionic strength to precipitate out?
Explanation / Answer
a.
Normality of acetic acid CH3COOH = 1.0N
Normality = moles equivalents of H+ * molarity
Molarity = Normality/mole equivalents of H+
Number of mole equivalents of H+ in CH3COOH = 1
b. Molarity = Normality = 1.0
pH = -log[H+] = -log[1.0] = 0
Since the egg white is neutral, pH would be 7 even after the addition of 1N acetic acid.
c.
(c)Sodium chloride (NaCl) is used for this experiment.This salt helps in precipitation of proteins from the solution when used at high concentration.High concentration of NaCl breaks the hydrogen bonds between amino acid strands and lead to protein denaturation.
d.
Three major proteins are found in egg white are ovalbumin,ovaglobulin and ovamucin.
Out of these three,ovamucin requires high ionic strength,ovaglobulin requires low ionic strength and ovalbumin requires the least ionic strength out of these three to precipitate out.