Identify pKa values of all hydrogens in 2-hydroxyl-2-phenylpropanoic acid.
An acid-base reaction of (R)-sec-butylamine with a racemic mixture of 2-phenylpropanoic acid forms two products having different melting points and somewhat different solubilities. Draw the structure of these two products. How are the two products related? Be sure to answer all parts. Report problem 45 Hint Solution NH2 ОН 1 points Guided Solution 03:50:34 2-phenylpropanoic acid (racemic mixture) (R)-sec-butylamine еВok Product with Product with References (S)-2-phenylpropanoic acid (R)-2-phenylpropanoic acid Anion Anion draw structure... draw structure... Cation Cation draw structure... draw...
OH pka 3.1 pKa 4.5 HO -OH pka 5.8 depicts the structure of citric acid with the corresponding pka values for each of the three acids. a. Explain why the carboxylic acid at the top of the structure is the most acidic. b. Suggest a reason why the remaining two acids would have different pka values.
Using Pauling’s rules, calculate the pKa values (all) of following acids: (PKa1,Pka2 or pka3 if acid is polyprotic) H3PO4, H3PO3 and H3PO2
Arsenic acid is a triprotic acid with the following pKa values: pKa 1 = 2.240; pKa2 = 6.960; pKa3 = 11.500. You wish to prepare 1.000 L of a 0.0400 M aresenate buffer at pH 10.430. To do this, you choose to mix the two salt forms involved in the second ionization, Na3AsO4 and Na2HAsO4, in a 1.000 L volumetric flask and add water to the mark. What mass of each salt will you add to the mixture?
Calculate Ka values for the following compounds. a) Acrylic acid (pKa = 5.25) b) Citric acid (pKa = 3.14)
Phenylalanine G can be synthesised from 3-phenylpropanoic acid E through intermediate F using the well-known Hell-Vollhard-Zelinsky reaction shown in Figure 1. CHBO Figure 1 (1) Identify the structure of intermediate F. [2 marks] (1) F from 3- Draw the mechanism for the formation of intermediate phenylpropanoic acid E. [6 marks) (i) Draw the mechanism for the formation of phenylalanine G from intermediate [1 marks) (iv) Outline two drawbacks to this method of amino acid synthesis. [2 marks)
Part The following data was collected from the titration curve. Identify the values for pka, pka , and paz. Volume (mL) 1.95 2.45 10.08 5.27 20.15 30.23 7.42 40.3 50.38 8.39 9.75 10.54 60.45
1. Why are the alpha (α) hydrogens of an aldehyde or ketone acid? 2. How do you identify that in an IR spectrum there is the presence of a disubstituted in ortho position? 3. Why is benzaldehide considered a molecule with no alpha (α) hydrogens?
sketch a titration curve for citric acid identify each pka on the graph and note the acid and salt at each step
For each of the acid-base reactions in Section, compare the pKa values of the acids on either side of the equilibrium arrows and convince yourself that the position of equilibrium is in the direction indicated. (The pka values you need can be found in Section 2.3 or in Problem.) Problem: a. Which is a stronger base, CH3COO-or HCOO-? (The pKa of CH3COOH is 4.8; the p£a of HCOOH is 3.8.) b. Which is a stronger base, HO- or-NH2? (The pka...