--%>
Assignment Help - homework help

Calculate PH value for a acetic acid

1. A solution of 0.100 M acetic acid is prepared.

a) What is its pH value?

b) If 20% of the initial acetic acid is converted to the acetate form by titration with NaOH, what is the resultant pH?

c) At what pH value would one expect to find a 1:1 ratio of the acetate and acetic acid forms?

d) At what pH value would one expect to find 10% of the total species (acetate + acetic acid) in the basic form?

e) At what pH value would one expect to find 90% of the total acetic acid species in the basic form?

2. Please refer to Section 1.1 - A Closer Look on page 9 of the text. Also consult A Closer Look 1.2 on page 10.

a) If initially the blood pH is 7.40, what is the concentration of CO2 in blood, assuming the pK' and bicarbonate level in the section entitled A Closer Look 1.2?

b) What would be the effect on blood pH of a 10% increase in the concentration of blood CO2?

c) If one wanted to return to the initial pH of 7.40, given the change in concentration of CO2, to what concentration would the blood HCO3- need to be adjusted?

d) A patient has a blood concentration of CO2 of 0.6 mM. If the blood pH is 7.40, what is the concentration of bicarbonate ion in the blood? If the blood [CO2] increases by 20% due to physiology, what is the new pH of the blood? What [HCO3-] would be needed to keep the blood pH of 7.40, if the physiology keeps the [CO2] elevated?

3. Your technician comes to you to ask for help. You've asked that a pH 7.20 buffer of Na2HPO4/NaH2PO4 of total concentration 0.2 M be prepared. He tells you that he has found a stock solution of 0.2 M NaH2PO4 and asks how to prepare the buffer. He also informs you that he has no Na2HPO4 on hand, but that there is a supply of both concentrated HCl(aq) and NaOH(aq) in the lab. The lab is equipped with a pH meter.

Assuming that any amount of strong acid or base that can be added will not dilute the stock solution by much, what guidance can you give him? All that you want to achieve is the pH 7.20 (as measured by the pH meter) buffer at a total concentration of about 0.2 M. Is there a "quick and dirty" way to obtain the desired buffer? What will be the ratio of the two relevant phosphate forms if you have achieved the intended result? Figure 1.6 and the information on page 10 of the text should be of great help to you.

4. You are studying an enzyme with a histidine side chain that is involved in enzymatic catalysis. It is thought that the basic form is important in catalysis. So, as part of your investigation of this enzyme, you wish to estimate the ratios of the basic and acidic forms of the histidine side chain at pH values of 6.0, 7.50 and 8.00. Assuming that the pK of the histidine in the enzyme protein is approximately equal to that in the free amino acid, calculate numerical estimates of the ratios of the basic to the acid forms of the histidine residue side chain at the given pH va

   Related Questions in Chemistry

  • Q : Hybridization Atomic orbitals can be

    Atomic orbitals can be combined, in a process called hybridization, to describe the bonding in polyatomic molecules. Descriptions of the bonding in CH4 can be used to illustrate the valence bond procedure. We must arrive a

    		•
  • Q : Problems related to entropy change A)

    A) Two compartments each of 1 m3 capacity are joined by a valve and insulated from the surroundings and from one another. One compartment has saturated steam at 683.6 kPa and the other contains steam at the same temperature but at a pressure of 101.3 kPa. T

    		•
  • Q : What do you mean by the term tripod

    What do you mean by the term tripod? Also state its uses?

    		•
  • Q : Explain polyhalogen compounds with

    Carbon compounds containing more than one halogen atom are called polyhalogen compounds. Most of these compounds are valuable in industry and agriculture. Some important polyhalogen compounds are described as follows:

    Q : Analytical chemistry 37% weight of HCl

    37% weight of HCl and density is 1.1g/ml. find molarity of HCl

    		•
  • Q : Inorganic Chemistry Inorganic

    Inorganic Chemistry:In the year 1869, Russian Chemist Dmitry Mendeleyev forms the periodic table of the element. Since Newlands did before him in the year 1863, Mendeleyev categorizes the el

    		•
  • Q : Concentration of Barium chloride Give

    Give me answer of this question. If 5.0gm of BaCl2 is present in 106 gm solution, the concentration is: (a)1 ppm (b)5 ppm (c)50 ppm (d)1000 ppm

    		•
  • Q : Which is polar HCl or HF Which one is

    Which one is polar HCl or HF?

    		•
  • Q : Electrochemistry ( electrolysis of

    1. Define Faraday's first law of electrolysis 2. define Faraday's second law of electrolysis

    		•
  • Q : Explain the process of adsorption in

    The process of adsorption can occurs in solutions also. This implies that the solid surfaces can also adsorb solutes from solutions. Some clarifying examples are listed below: (i) When an aqueous solution of ethano

    		•