A sufficient quantity of each of the following aqueous solutions has been made available to you: (i) 0.2M NaH2PO4; (ii) 0.1M Na2HPO4    (a) How many ml of each of these two solutions would you require to mix together in order to prepare one litre of a 0.01M phosphate buffer pH 7.2? [For H3PO4: pKa1 = 2.15; pKa2 = 6.82; pKa3 = 12.38].  (Ans. = 14.7 ml 0.2M NaH2PO4; and 70.6 ml Na2HPO4).  (b) Having calculated these volumes (of 0.2 M NaH2PO4 and 0.1M Na2HPO4) required, what further steps would you take to prepare the 0.01M phosphate buffer solution of pH 7.2?

An aqueous buffer solution of volume 100 cm3 consists of 0.20 M CH3COOH and 0.20 M NaCH3CO2.         pKa value of CH3COOH is 4.75.  (a) Predict the pH value of this solution.  3 sig. fig. (b) Predict the pH value after adding 5.92 mmol NaOH (note, not mM. Volume is not 1 L) to this buffer solution assuming volume is not changed.  3 sig. fig.

t ent Determine the pH during the titration of 64.4 mL of 0.443 M acetic acid (K₂ = 1.8x10-5) by 0.443 M KOH at the following points. (Assume the titration is done at 25 °C.) (a) Before the addition of any KOH (b) After the addition of 16.0 mL of KOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 96.6 mL of KOH

The substance acetylsalicylic acid (aspirin) (HC,H704) is a weak acid (Ka = 3.0×10-4). What is the pH of a 0.191 M aqueous solution of potassium acetylsalicylate, KC,H704? pH = || This solution is

A solution is made by dissolving 0.111 moles of N2H4 (Kb = 3.0 x 10-6 ) and 0.199 moles of N2H5Cl in water and diluting to 1.00 L. What is the pH of the resulting solution?

A 250-mL buffer solution contains 0.0510 mole of KH2PO4 and 0.0875 mole of K2HPO4. (a) Calculate the molar concentrations of H2PO4–and HPO42–, respectively, in thesolution. (b) What is the pH of the solution? (H2PO4– has Ka = 6.2 x 10–8) (c) Write a net ionic equation for the buffering reaction against a strong acid by this buffer. (d) If 0.012 mole of hydrochloric acid (HCl) is added to the solution, create a reaction table to show the buffering reaction and calculate the molar concentration of H2PO4–and HPO42–, respectively, in the resulting solution after the buffering reaction. (e) What is the pH of the resulting solution?

3b.) The Ka of acetic acid is 1.8 x 105. Calculate the pH of the following solutions: b. A solution consisting of 0.10 M acetic acid (HC2H302) and 0.50 M sodium acetate (NAC2H3O2).

9) The dissociation equilibrium constants for the protonated form of alanine (a diprotic amino acid, H₂X+) are Kal = 4.6 × 10-3 and Ka2=2.0 × 10-10. What is the pH of 50.00 mL of a 0.050 M solution of alanine after 37.50 mL of 0.100 M NaOH has been added? Para Ofind moles

A 25.0 mL sample of 0.450 M (CH3)2NH is titrated with HBr. What is the pH of the solution after 30.0 mL of 0.375 M HBr have been added to the methylamine solution? ((CH3)2NH; Kb Give answer to 2 decimal places. = 5.9×10-4)

Determine the pH of a 10-3 mol/L solution of (a) hydrogen sulfate ion (pKa = 1.99), (b) formic acid (pKa = 3.75), (c) hypochlorous acid (pKa = 7.53), (d) phenol (pKa = 9.98)