The pKa of chloroacetic acid is 2.9. If an organic chemist has a 0.10 M aqueous solution of chloroacetic acid at pH 2.4, what percentage of molecules/ions will be in the basic form?
Let's denote the acid by HA and proceed to set up an ICE table with equilibrium dissociation of α. Also at pH = 2.4, there will be an initial H+ concentration of 3.98 * 10-3 M
HA → H+ + A-
initial conc: 0.1 3.98 * 10-3 0
equilibrium conc: 0.1(1-α) 3.98 * 10-3 + 0.1α 0.1α
We have pKa = 2.9
-log(Ka) = 2.9
Ka = 1.26 * 10-3
From the equation, Ka = [H+] * [A-] / [HA]
1.26 * 10-3 = (3.98 * 10-3 + 0.1α )* 0.1α / 0.1(1-α)
Since α<<1, we assume 1-α = 1
Solving the equation, we have: α = 0.094
Since this is the fraction of acid that has dissociated, we can say that % of Base form = 100 * α= 9.4%
The pKa of chloroacetic acid is 2.9. If an organic chemist has a 0.10 M aqueous...
Chloroacetic acid, HC2H2O2Cl, is a stronger monoprotic acid than acetic acid. In a 0.10 M solution, the pH is 1.96. Calculate the pKa for chloroacetic acid. pKa =
Chloroacetic acid, HC2H2O2Cl, is a stronger monoprotic acid than acetic acid. In a 0.10 M solution, the pH is 1.96. Calculate the Kafor chloroacetic acid. Calculate the pKa for chloroacetic acid. Use the correct number of significant figures.
3) The pKa of chloroacetic acid is 2.9; the Ka is 1.4 x 103. Complete the following table for solutions of chloroacetic acid in water: H-O H CI H20 OH Concentration (M) [H3O*] pH 0.40 0.60 0.80 1.00 1.20
A 0.10 M pyridine solution has a pH of 5.87. To the nearest hundredth of a unit, what is the ratio of pyridinium ions (pKa = 5.3) to neutral pyridine molecules at this pH? A 0.10 M pyridine solution has a pH of 5.99. To the nearest hundredth of a unit, what fraction of the molecules are in the neutral form? (The pKa of the pyridinium ion is 5.3.)
In a 0.0020 M solution of chloroacetic acid, (HC2O2Cl , pKa=2.85), what are the concentrations of a all species present, including OH-, and what is the pH?
Which of the following 0.10 M aqueous solutions gives the highest pH? A) CH3COOH (pKa = 4.75) B) HF (PK:= 3.45) C) H3PO4 (pKal = 2.12) D) HCIQ (Ka=2.00) E) Since all are acids, the pH is the same for all solutions. 5. Which one of the following salts gives an acidic aqueous solution? A) CsNO3 B) CaCl2C ) LiF D) Cr(CIO4)3 E) NaCH3CO2 6. 7. All of the following are strong acids except A) HCIQB) HC104 C) HI D)...
Question 6 (2 points) Chloroacetic acid, HC2H2CIO2, has a greater acid strength than acetic acid, because the electronegativity chlorine atom pulls eloectroms way from the O-H bond and thus weakens it. What is the pH of a 0.043 M aqueous solution of chloroacetic acid? The Ka for HF is 1.3x10-3. You must solve the quadric equation for this problem. Express your answer to two decimal places. Your Answer: Answer s7 Question 7 (2 points) What is the pH of a...
Find the nominal concentrations of the weak acid or base in each of the following aqueous solutions: (a) HClO, pH = 4.6; (b) hydrazine, NH2NH2, pH = 10.2 The percentage ionization of benzoic acid in a 0.110 mol·L–1 solution is 2.4%. What is the pH of the solution and the pKa of benzoic acid?
A chemist prepared an aqueous buffer containing both formic acid (HCOOH) and the formate anion. The volume of the buffer is 100 mL ; with [HCOOH] = 0.110 mol L-1 and [HCOO- ] = 0.101 mol L-1 . The pKa of HCOOH = 3.74. What is the pH of this buffer? Write down the balanced chemical equation that describes the reaction of this buffer when an HCl solution is added. c) What is the resultant pH of this solution after...
What concentrations of acetic acid (pKa=4.76)(pKa=4.76) and acetate would be required to prepare a 0.10 M0.10 M buffer solution at pH 4.6pH 4.6? Note that the concentration, pH value, or both may differ from that in the first question. Strategy Rearrange the Henderson–Hasselbalch equation to solve for the ratio of base (acetate) to acid (acetic acid), [A−]/[HA][A−]/[HA] . Use the mole fraction of acetate to calculate the concentration of acetate. Calculate the concentration of acetic acid. Step 1: The ratio...