A phenol/phenolate buffer was made up by mixing 0.0125 mol of phenol (C6H5OH) and 0.0135 m of phenolate (C6H5O) in 500 mL of water. The following equilibrium is established in this buffer: C6H5OH(aq) + H₂O(1) C6H5O (aq) + H3O+ (aq) Given that K₂(phenol) = 1.3 x 10-10, the pH of this buffer is:

Which of the following buffers will best prevent changes in pH when 100 µl of 1.0 M HCl is added to a solution initially at pH 7.25? Buffer Acetate Bicine CAPS HEPES Phosphate Tris 0.1 M HEPES 0.01 M HEPES O 0.1M Bicine 0.1 M Acetate Buffer 0.01 M Bicine 0.01 M Acetate Buffer chemical form acid; liq. (17.4 M) base; Na-acetate-3H₂O K₂HPO4 free base Tris-HCI KH₂PO4 F.W. (g/mol) 60.05 136.08 163.19 221.3 238.3 174.2 121.14 157.6 136.10 pka at 20 °C 4.76 4.76 8.35 10.40 7.55 2.12 12.32 8.30 8.30 7.21

Acetic acid and a salt containing its conjugate base, such as sodium acetate, form buffer solutions that are effective in the pH range 3.7-5.7.  (a) In resisting a pH change, which buffer component would react with NaOH? Explain. (b) What happens to the buffer activity when this component is exhausted?

To a buffer containing 0.150 mol NH3 and 0.250 mol NH4 0.050 mol of HCl (aq) is added. Calculate the pH of the solution given that Ko of NH3 is 1.8 x 10-5.

When a 23.3 mL sample of a 0.379 M aqueous hypochlorous acid solution is titrated with a 0.407 M aqueous sodium hydroxide solution,(1) What is the pH at the midpoint in the titration? (2) What is the pH at the equivalence point of the titration? (3) What is the pH after 32.5 mL of sodium hydroxide have been added?

1. the temperature for each solution is carried out at approximately 297 K where Kw = 1.00 x 10 ^-14 (a) 0.20 g of hydrogen chloride (HCl) is dissolved in water to make 4.5 L of solution. What is the pH of the resulting hydrochloric acid solution? (b) 0.70 g of sodium hydroxide (NaOH) pellets are dissolved in water to make 3.0 L of solution. What is the pH of this solution ?

Consider the titration of 40.0 mL of 0.200 mol/L HCOONa (aq) with 0.300 mol/L HCI (aq). Ka for HCOOH is 1.8×104. Determine the pH of the original solution. Use the given values to set up an ICE table. Determine the unknown equilibrium concentrations. Initial (M) Change (M) Equilibrium (M) 1 HCOONa(aq) H₂O(1) HCOOH(aq) OH (aq) 5 RESET

Consider the titration of 36.0 mL of 0.123 M ammonia with 0.0766 M HCl. (See the Acid-Base Table attached.) (a) How many mL of HCl are required to reach the equivalence point?57.8  mL(b) What is the pH at the equivalence point? 5.29(c) What is the pH of the solution after the addition of 17.2 mL of acid? (d) What is the pH of the solution after the addition of 84.3 mL of acid? (only need help witn c and d)

culate the pH of a buffer solution 1) Calculate the pH of a solution prepared by dissolving 2.05 g of sodium acetate, CH3COONa, in 85.0 mL of 0.10 Macetic Assume the volume change upon dissolving the sodium acetate is negligible. K₂ of CH3COOH is acid, CH3COOH(aq). 1.75 x 10-5. pH =

A chemistry graduate student is given 250, ml, of a 1.30 M pyridine (C5H5N) solution, Pyridine is a weak base with Kg = 1.7 x10^-9. What mass of C5H5NHBr should the student dissolve in the C5H5N solution to turn it into a buffer with pH = 5.227 You may assume that the volume of the solution doesn't change when the C5H5NHBr is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.