1.What is the pH of a solution containing 0.042 M NaH2PO4 and 0.058 M Na2HPO4 ? The pKa of sodium phosphate is 6.86. pH = 6.86 + log [0.058] / [0.042]; pH = 6.86 + 0.14; pH = 7.00
That is my answer to the above question. The following question is what I am having trouble with.
2.What is the pH of the sodium phosphate buffer described in problem #1 if 1 ml of 10M NaOH is added? What is the pH of 1 liter of water if 1ml of NaOH is added?

  1. 👍
  2. 👎
  3. 👁
  1. 2a. Adding 1 mL of 10M NaOH to HOW MUCH of the buffer. Since the problem gives molarities, I will assume 1L.
    millimols HPO4^2- = 1000 mL x 0.058 = 58
    mmols H2PO4 = 1000 mL x 0.042 = 42
    mmols NaOH added = 1 mL x 10M = 10

    .......H2PO4^- + OH^- ==> HPO4^2- + H2O

    pH = 6.86 + log(68/32) = about 7.19

    10M NaOH x (1/1001) = 0.00999M
    pOH = 2
    pH = 10
    Check my work for typos. The chemistry is ok.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. college chemistry

    which of the following combinations is not suitable for making a buffer? h3po4 and nah2po4 na2co3 and nahco3 nh4cl and nh3 nah2po4 and na2hpo4 hclo4 and naclo4

  2. Chemistry

    pKa1 = 2.148, pKa2 = 7.198, pKa3 = 12.375 You wish to prepare 1.000L of a 0.0100M Phosphate buffer at pH7.55. To do this, you choose to use mix the two salt fomrs involved in the second ionization, NaH2PO4 and Na2HPO4, in a 1.000L


    Sufficient strong acid is added to a solution containing Na2HPO4 to neutralize one-half of it. what will be the pH of this solution? Explain please

  4. Analytical Chemistry

    Phosphoric acid is a triprotic acid with the following pKa values: pka1: 2.148 pka2: 7.198 pka3: 12.375 You wish to prepare 1.000 L of a 0.0100 M phosphate buffer at pH 7.45. To do this, you choose to use mix the two salt forms


    What would be the pH of a solution prepared by combining equal quantities of NaH2PO4 and Na2HPO4? Explain with an equation.

  2. Mechanics

    Typically, a tennis ball hit during a serve travels away at about 51 m/s. If the ball is at rest mid-air when struck, and it has a mass of 0.058 kg, what is the change in its momentum on leaving the racket? Show the solution and

  3. chemistry

    What is the chemical equation that describes the complete neutralization of H3PO4 by NaOH? A. H3PO4 + 2NaOH Na2HPO4 + 2H2O B. H3PO4 + H2O H2PO4- + H3O+ C. H3PO4 + NaOH NaH2PO4 + H2O D. H3PO4 + 3NaOH Na3PO4 + 3H2O

  4. Chemistry

    What is the ionic strength of 0.2 M Na2HPO4 in a solution?

  1. chemistry

    Phosphoric acid is a triprotic acid, so H3PO4, H2PO4 -, and HPO4 2- are all acids. Which of the solutions below would have the lowest pH? 0.1 M NaH2PO4 0.1 M Na2HPO4 0.1 M Na3PO4

  2. Chemistry

    Calculate the pH of a buffer solution obtained by dissolving 16.0 g of KH2PO4(s) and 27.0 g of Na2HPO4(s) in water and then diluting to 1.00 L. (pKa=7.21)

  3. Chemistry

    A buffer solution of volume 100.0 mL is 0.150 M Na2HPO4(aq) and 0.100 M KH2PO4(aq). Refer to table 1. (a) What are the pH and the pH change resulting from the addition of 80.0 mL of 0.0500 M NaOH(aq) to the buffer solution? pH pH

  4. Chem

    What is the pH of .1M: FeSO4 Na2HPO4 NaH2PO4 NaF

You can view more similar questions or ask a new question.