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How would you prepare 250ml of 0.2M sodium phosphate buffer of PH 6.4 if the following chemicals are available :dibasic sodium phosphate,monobasic sodium phosphate and 0.129M solution of NaOH. Assume that the pka1 pka2 pka3 of phosphoric acid are 2.12,

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  1. Biochemistry

    How would you prepare 250ml of 0.2M sodium phosphate buffer of PH 6.4 if the following chemicals are available :dibasic sodium phosphate,monobasic sodium phosphate and 0.129M solution of NaOH. Assume that the pka1 pka2 pka3 of phosphoric acid are 2.12, 6.8
  2. 12

    i am confuse to prepare the buffer please tell me how to prepare the 0.02 M Sodium phosphate buffer, pH 6.9 with 0.006 M sodium chloride
  3. Chemistry

    Prepare 250ml of 0.2M phosphate buffer of pH 6.4.starting from Na2HPO4,NaH2PO4,0.129N NaOH solution.
  4. Biochemistry

    You are asked to prepare 2 L of 50 mM sodium phosphate pH 7.0. The pK2 of phosphate is 6.8. What are the amounts of sodium phosphate mono basic monohydrate (NaH2PO4 • 1H2O, MW=137.99 Da) and anhydrous sodium phosphate dibasic (Na2HPO4, MW=141.96 Da) that
  5. science

    How do i prepare 0.1 ml KH2PO4-KOH buffer, PH 7.4 (20mM)? Deoxyribose (2.8mM) - EDTA (0.1 mM) - H2O2 (1mM) - vaniline10 mM - phosphate buffer pH 6.9 - Phosphate buffer, 20mM - Phosphate buffer 0.1 M (pH 7.4) - Ascorbate (0.1mM). ( please i want the amount
  6. BioChem

    1.Suppose you had a buffer containing 0.5 moles of sodium monobasic phosphate and 0.5 moles of sodium dibasic phosphate. How many moles of hydrochloric acid would this phosphate buffer be able to accept before the pH of the solution began to change
  7. biochem

    I have 0.500ml of 3M ethanol and then I take 0.250ml of it and put it to 0.250ml of 0.06M phosphate buffer, what is the final concentration?
  8. chemistry

    how to prepare 500ml of a 0.75M Sodium Phosphate buffer solution at pH 7.5, how would you go about doing that?
  9. Chemistry

    The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO−4 and the conjugate base is HPO2− 4. You want the concentration of the
  10. Chemistry

    If you need to prepare 250.0 mL of a pH 5.00 buffer that has a total buffer concentration of acetic acid + sodium acetate of 0.050M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with
  11. Chemistry

    Which of the following is the most effective buffer system for a pH value of 7.45? Assume all are 1M A. Carbonic acid and sodium bicarbonate B. Sodium bicarbonate and sodium carbonate C. Sodium dihydrogen phosphate and disodium hydrogen phosphate D
  12. Chem

    If you need to prepare 250.0 mL of a pH 5.00 buffer tha t has a total buffer concentration of acetic acid + sodium acetate of 0.050 M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with
  13. Chemistry(Please check answers)

    1)What is the pH of a saturated solution of lead(II) hydroxide? The Ksp= 4.0e-15 Pb(OH)2 4.0e-15 = (x)(2x)^2 = 4x^3 I divided by 4 and took the cube root and got 1.12e-5 but I am not sure I took the cube root correctly. -log(1.12e-5)= 4.95 14-4.95 = 9.05
  14. chemistry

    If you need to prepare 250.0 mL of a pH 5.00 buffer tha t has a total buffer concentration of acetic acid + sodium acetate of 0.050 M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with
  15. Chemistry

    You are asked to prepare a pH=4.00 buffer starting from 1.50 L of 0.0200 \; M solution of benzoic acid C_6 H_5COOH and an excess of sodium benzoate C_ H_5 COONa. How many grams of sodium benzoate should be added to prepare the buffer? Neglect the small
  16. biochemistry

    perform the calculation required for100ml of 0.2 M sodium acetate buffer of pH 5.0. If you are given a bottle of sodium acetate acetate(mw =82 and a bottle of concentrated HCl of normality =11.7). After the calculation, prepare the buffer , check the pH of
  17. Biochem

    5. The glass electrode used in commercial pH meters gives an electrical response proportional to the concentration of hydrogen ion. To convert these responses to a pH reading, the electrode must be calibrated against standard solutions of known H+
  18. chemistry

    Using 0.1M phosphate buffer, pH 7.2, prepare 25ml each of the buffer solutions with the following concentrations at pH 7.2: 1. 0.005M 2. 0.05M 3. 0.010M
  19. Chemistry

    How would you calculate the pH of the buffer if 1.0mL of 5.0M NaOH is added to 20.0mL of this buffer? Can someone please explain to me how to do B and C step by step so I could understand it clearly? :) Say, for example, that you had prepared a buffer in
  20. Chemistry

    How would you calculate the pH of the buffer if 1.0mL of 5.0M NaOH is added to 20.0mL of this buffer? Can someone please explain to me how to do B and C step by step so I could understand it clearly? :) Say, for example, that you had prepared a buffer in
  21. Chemistry

    I have the answer to this question but the book does not explain WHY this is a good buffer solution? It uses pH=pKa - log(base/acid) and shows 7.2=7.2 - log(1). I don't understand why they can only use pKa7.2 and ignore the pKa 12.7. You are instructed to
  22. chemistry

    Sodium phosphate dodecahydate reacts with barium chloride dihydrate. If Na2SO4 is an unkown contaminant of sodium phosphate dodecahydrate, how does it presence affect yeild of sodium phosphate in the exexpiriment?
  23. chemistry

    In protein precipitation, two liters of 5mM buffer solution with pH 5.2 is needed in the isolation of albumin. Which among the buffer solutions is best fitted for the said purpose?justify your answer. a. acetate buffer with pka=4.73? b. tris-aminomethane
  24. Chemistry

    Which of the following will buffer near pH=9? a. 0.5M sodiumacetate/0.5M acetic acid b. 0.5M ammonium chloride/0.5M ammonia c. 0.5M sodium dihydrogen phosphate/0.5M hydrogen phosphate i think a) 0.5M sodiumacetate/0.5M acetic acid will buffer near pH=9
  25. Chemisrty

    what mass of sodium phosphate is required to make 250mL of 0.10mol/L solution?
  26. Chemistry- HW Check

    I have seven homework problems. I did them but I wasn't sure if I did them correctly. Did I do them correct? Thank you! Give the reaction that describes how the hydrazine, N2H4(aq), / hydrazinium ion, N2H51+(aq), buffer reacts with a strong base such as
  27. Chemistry

    The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO− 4 and the conjugate base is HPO2− 4 . You want the concentration of
  28. Chemistry

    A student dissolves 22.4 g of sodium phosphate to prepare a 2.98 L solution. Another student then dilutes this solution to 4.90 L. If sodium phosphate completely dissociates, determine the number of mols of each ion in the final solution.
  29. Chemistry

    35 grams of sodium phosphate are mixed with enough water to make 3.5L of solution having a densityof 1.045g/mol. Find the concentration of sodium phosphate in ppm. Using the same information, find the molarity of the sodium and phosphate ions.
  30. chemistry

    I posted a question several days ago: The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO−4 and the conjugate base is
  31. Biochemistry Phosphate buffers

    Prepare 250mL of 0.02 M Phosphate buffer in which [H2PO4]- = [HPO4]- Calculate the volumes of 2 M phosphoric acid and 1 M NaOH required. To a 250 ml volumetric flask containing about 100 ml of water, transfer the required volumes of 2 M phosphoric acid and
  32. chemistry

    A precipitate of calcium phosphate is formed when aqueous solutions of sodium phosphate and excess calcium chloride are mixed. If 100.0 mL of 1.5 M sodium phosphate solution is the limiting reactant, how many grams of calcium phosphate can be expected?
  33. chemistry

    The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO− 4 and the conjugate base is HPO2− 4 . You want the concentration of
  34. Biology

    I know that the phosphate [cells] and sodium barcarbonate [blood plasma] buffer systems are two examples of biological buffers; however, i am writing an essay for bio and i need a third example. does anyone know of a third biological buffer system?
  35. chemistry

    Choices: True,False. Select all that are True. The pH at the equivalence point of a weak base with a strong acid is expected to be less than 7 because of the presentce of the conjugated acid in the water. One cannot prepare a buffer from a strong acid and
  36. Chemistry

    You want to prepare a pH=4.50 buffer using sodium acetate and glacial acetic acid. You have on hand 300 mL of 0.100 M sodium acetate. How many grams of glacial (water free) acetic acid should you add to prepare the buffer? (Ka of acetic acid is 1.8e-5 at:
  37. chemistry

    Calculate the mass of sodium phosphate required to prepare 1.75 L of solution in which the sodium ion concentration is 0.25 mol/L
  38. Chemistry

    you need to prepare 100 ml of ph=3.50 buffer solution using 0.100 M formic acid and 0.200 M sodium formate. how much of each solution shoudl be mixed to prepare this buffer?
  39. Chemistry

    You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.240 M sodium benzoate. How much of each solution should be mixed to prepare this buffer?
  40. Chemistry

    You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.180 M sodium benzoate How much of each solution should be mixed to prepare this buffer?
  41. Chemistry

    c) Now make up 500 mL of a 0.025M phosphate buffer using the 0.1M phosphate buffer. Show all your workings. The 0.1M is made of 120.1ml conjugate base and 379.9ml acid.
  42. Chemistry

    c) Now make up 500 mL of a 0.025M phosphate buffer using the 0.1M phosphate buffer. Show all your workings. The 0.1M is made of 120.1ml conjugate base and 379.9ml acid.
  43. Analytical Chemistry

    This question pertaining to buffer systems! How would you prepare 10.0mL of 0.0100M phosphate buffer, pH = 7.4 0, from stock solution of 0.100M KH2PO4 and 0.250M K2HPO4, pKa of KH2PO4 is 7.20. Please help me in figuring out how I even start this
  44. Chemistry

    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
  45. Chem

    Calculate the volume of .300 M NaOH needed to prepare a pH=3.50 buffer with 250ml of .075M HF solution. pKa (HF) = 3.15
  46. chemistry

    How would you prepare 500 ml of a 1.8 M phosphate buffer (pH 6.8) containing 4.5 x 10-6 M CaCl2 and 52 mM sucrose?
  47. science

    How to prepare 250ml (n/10) sodium hydroxide solution (NaoH)
  48. pharmachemistry

    How can i prepare a 100ml, 0.1M phosphate buffer solution (pH = 5) out of Na2HPO4 and NaH2PO4
  49. science

    How can i prepare a 100ml, 0.1M phosphate buffer solution (pH = 7) out of Na2HPO4 and NaH2PO4
  50. BIOCHEMISTRY

    WHAT METHOD CAN BE USED TO PREPARE 0.2M POTASSIUM PHOSPHATE BUFFER USING KH2PO4 AND KOH?
  51. chemistry

    prepare a phosphate buffer with pH= 7 from solid NaH2PO4 (pKa =7.21) and Na2HPO4. 1) calculate the ratio of [CB]/[acid] I got the ratio as 0.62 2) calculate the mass of each component required to make 1L of a .1 M buffer solution 3) if the pH is 7.10, how
  52. Science

    The mass of sodium carbonate required to prepare 250ml of 0.4N solution is
  53. Chemisty

    How many moles of H2PO4 and HPO4 would be needed to prepare 1.0 L of a 0.01M phosphate buffer with a pH of 6.82?
  54. Science

    How would you prepare 10 mL of 0.08 M NaCl in sodium acetate buffer? (Stock Sodium acetate buffer: 0.1 M)
  55. Chemistry check and help

    what is ... Sodium bisulphate hydroiodic acid ammonium dihydrogen phosphate Zn(HCrO4)2 Calcium metal ferrous bromide sodium carbide phosphate radical Check... sodium bicarbonate NaHCO3
  56. Biochemistry

    How would i make phosphate buffer 0.3M pH 6.5 1L using sodium mono and dibasic solutions?
  57. chemistry

    describe an alternative method to prepare a 0.2M potassium phosphate buffer using KH2PO4 and KOH
  58. Chemistry

    How do you prepare one liter of phosphate buffer 0.01 M at pH 12.0 from 85% phosphoric acid (density 1.69g/ml) and NaOH 1.0 M
  59. Biochemistry

    Susie is instructed to prepare 400mL of a 0.3M acetate buffer of pH=4.44, and she is given sodium acetate trihydrate and glacial acetate acid (99% by weight, density=1.05 g/mL0. Susie can't figure out what to do! How should she prepare this buffer? Acetic
  60. chemistry

    In the sorensen phosphate buffer system, what is the monohydrogen phosphate to dihydrogen phosphate ratio that will give a pH of 8.2? How do I know which is [A-] and which is [HA]?
  61. chemistry 2

    You are instructed to create 800. mL of a 0.69 M phosphate buffer with a pH of 7.6. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. what is the molarity needed for the acid component of the buffer?What is the molarity
  62. Science

    17. You need to conduct an experiment in the laboratory. This requires that you prepare 500 ml of sodium acetate buffer with pH = 4.30. In laboratory you have solution of CH3COOH (pKa = 4.75), and a stock of CH3COONa.3H2O (MW=136.082 g/mol). Using the
  63. Chemistry

    How would you prepare 1L of a .050 M phosphate buffer at pH 7.5 using crystalline K2HPO4 and a solution of 1 M HCl? pka of H2PO4 = 7.2
  64. Chemistry

    You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.220 M sodium benzoate. How much of each solution should be mixed to prepare this buffer? mL of benzoic acid ? mL of sodium benzoate?
  65. Chemistry

    If a liter of a buffer is prepared with a final concentration of .3M monosodium phosphate and .5M disodium phosphate, what is the pH of this buffer? (Hint: Which is conjugate acid (HA) and conjugate base (A-)? What's the pKa for this particular pair of HA
  66. Chemistry

    Calcium can also be precipitated out of the solution by adding sodium phosphate (Na3PO4) to form solid calcium phosphate. A.) write a net ionic equation for this process B.)calculate the mass of this precipitate you would generate from treating 1.000 L of
  67. chemistry

    Hard Water often contains calcium chloride. The calcium ion in solution can be detected using a solution of sodium phosphate. When a solution of calcium chloride is mixed with a solution of sodium phosphate, a precipitate forms. a. What is the chemical
  68. chemistry

    1L of a buffer composed of acetic acid and sodium acetate has a pH of 4.3. Adding 10mL of 2M sodium hydroxide solution to 100mL of this buffer causes the pH to rise to 4.87. what is the total molarity of the original buffer?
  69. AP Chemistry

    A precipitate is formed by adding 20.0 ml of 0.200M of sodium phosphate to 30.0 ml of 0.50M Copper sulfate. Please write the ionic equation Sodium phosphate and copper sulfate are both soluble, whilst copper phosphate is not. So, copper ions meet phosphate
  70. chemistry

    A chemist wishes to prepare 250mL of a buffer that is pH = 4.50. Beginning with 100mL of 0.12 mol L^(-1) acetic acid and a supply of 0.10 mol L^(-1) NaOH, explain how this could be done. How much 0.20 mol L^(-1) NaOH must be added to this buffer to raise
  71. Analytical chemistry

    0.6140 grams of sodium phosphate (Na3PO4) was dissolved in 2 L of water to make a stock solution. 34 mL of this solution is then diluted to 100mL volumetrically to prepare the final solution. Calculate the molarity of phosphate ions in this solution.
  72. Biochemistry

    you have a 0.200L of solution containing 250mM phosphate buffer, pH 6.8. An equivalent amount of HCl/NaOH with respect to the total amount of phosphate in the buffer --> mmol of NaH2PO3 + mmol of NaH2PO4 = 50 mmoles. What would the pH of the above buffer
  73. Chemistry

    TRUE OR FALSE? 1) A solution that is made out of 1.00mol/L ammonia and 0.50mol/L of ammonium chloride is a basic buffer. 2) The pH at the equivalence point of a weak base with a strong acid is expected to be less than 7 because the acid that is added is
  74. Biochemistry

    calculate the mass of the species required to prepare a phosphoric acid buffer with a voncentration of 0.34M ,volume of 500ML and a PH of 11.8.calculate the mass of the varies species needed to prepare the buffer.salt of interest is sodium. consider the
  75. Chemistry

    You have 250mL of a 0.56M solution of sodium acetate. How many mL of 0.50M acetic acid should be added to make a buffer of pH 4.40? I think this is a buffer system so I would use pH=pka + log base/acid so would I set this up as 4.40 = 4.74 + log base/
  76. Chemistry

    Can someone please check my work? Calculate the mass of (NH4)2S2O8 needed to prepare 250mL of a 0.100M solution. I got 5.705 g. Calculate the volume of 2.00M KI needed to prepare 250mL of a 0.200M solution. I got 0.025L or 25mL. Calculate the volume of
  77. Chemistry: Buffer Intensity problem

    You wish to prepare a pH 4.76 acetic acid sodium acetate buffer with a buffer intensity of 1 M per pH. What concentrations of acetic acid and sodium acetate are needed?
  78. Chemistry

    28. Explain, in terms of equilibrium shifts, how this buffer mixture resists changes in pH when small quantities of both a strong acid and a strong base are added. The buffer mixture was made up of: monosodium phosphate(NaH2PO4) and disodium phosphate
  79. Chemistry

    If 25g of lead phosphate reacts with an excess of sodium nitrate, how many dreams of sodium phosphate is produced?
  80. chemistry

    Assignment 1 Question Consider a monohydrogen phosphate ( HPO42-) and dihydrogen phosphate (H2PO4-) buffer solution. [HPO42-] = 0.063M [H2PO4-] = 0.10M What happens when you add 1.0 ml of 0.10 M HCl to the a 99ml solution? What would the pH of the solution
  81. chemistry laboratory

    1. prepare a buffer solution by using acetic acid and sodium acetate.2. prepare M/40 NAOH solution.
  82. Chemistry

    A student was required to prepare 250.0 mL of a hypochlorous acid/sodium hypochlorite buffer in which the concentration of the weak acid component was 0.073 M and the concentration of the conjugate base was 0.046 M. The student was supplied with 0.365 M
  83. Biochemistry

    Show Calculations used in mkaing 250mL of 0.5M sodium acetate ph 4.7. You are given: 1M acetic acid (weak acid) 1M sodium hydroxide (strong base) Sodium acetate buffer: ph 4.7 acetic acid pKa: 4.7 So far this is what I've gotten: pH = pKa + log (A-/HA-)
  84. chemistry

    You prepare a buffer solution by dissolving 2.00 g each of benzoic acid, C6H5COOH, and sodium benzoate, NaC6H5COO, in 750.0 mL water. (2 pts each) a) What is the pH of this buffer? Assume that the solution’s volume is 750.0 mL. b) If 0.55 mL of 12 M HCl
  85. chemistry

    What is the freezing pint of 0.0091 m aqueous sodium phosphate, Na3PO4? Assume that sodium phosphate is a strong electrolyte and it functions ideally in solution. (express your answer in degrees Celsius)
  86. Chemistry

    You prepare a buffer solution by dissolving 2.00 g each of benzoic acid, C6H5COOH and sodium benzoate, NaC6H5COO in 750.0 mL of water. What is the pH of this buffer? Assume that the solution's volume is 750.0 mL.
  87. Biochemistry

    you have a 0.200L of solution containing 250mM phosphate buffer, pH 6.8. An equivalent amount of HCl/NaOH with respect to the total amount of phosphate in the buffer --> mmol of NaH2PO3 + mmol of NaH2PO4 = 50 mmoles. What would the pH of the above buffer
  88. chemistry

    If you add 5.0 mL of 0.50 M NaOH solution to 20.0 mL to Buffer C, what is the change in pH of the buffer? (where buffer C is 8.203 g sodium acetate with 100.0 mL of 1.0 M acetic acid) I have calculated the pH of buffer C to be 4.74. Now what? =\
  89. Chemistry

    Using a 0.25 M phosphate buffer with a pH of 6.6, you add 0.71 mL of 0.51 M HCl to 49 mL of the buffer. What is the new pH of the solution? (Enter your answer to three significant figures.) Using a 0.25 M phosphate buffer with a pH of 6.6, you add 0.71 mL
  90. chemistry

    How would you prepare 1.000 L of a 0.200 M phosphate buffer at pH 7.02 using crystalline Na2HPO4 and a solution of 1.000 M HCl?
  91. chemistry

    How would you prepare 1.000 L of a 0.200 M phosphate buffer at pH 6.90 using crystalline Na2HPO4 and a solution of 1.000 M HCl?
  92. Chemistry

    Phosphate standards used to generate the calibration curve are usually made by first preparing a stock solution of known concentration, then diluting it to the required concentration. First prepare a stock solution that is 1.00 x 10-2 M in phosphate ion.
  93. Food Chemistry

    Calculate the amounts and pH values for preparing the following acetic acid/acetate buffer solution. 1.) In the first step, If you plan to prepare a 2.00 M sodium acetate in 200.0 mL distilled water, how many grams of sodium acetate should be added in
  94. chemistry

    1L of a buffer composed of NaHC2O4 and Na2C2O4 has a pHof 4.0 and a total molarity of 1. a). what would the effect on the pH be of adding 1 gram of sodium hydrogen oxalate to this buffer? b). what would be the effect on the pH of adding 1 gram of sodium
  95. Chemistry

    how would you prepare 250 mL solution containing the following: 0.30 M mannitol, 0.025 M phosphate buffer pH 7.5? You are given solid mannitol, kh2po4, and k2hpo4. (pKa=6.86)
  96. Chemistry

    Calculate the solid needed to make a 250ml solution that is 0.34M in sodium cation, using sodium sulfate decahydrate. I came up with 13.685g. but how do I make that into 250ml of a solution that is0.34M in sodium cation?
  97. Chemistry

    How many moles of H2PO4 and HPO4 would be needed to prepare 1.0 L of a 0.01M phosphate buffer with a pH of 6.82? Use the Henderson-Hasselbalch equation. pH = pKa + log (base)/(acid). Thank you, but I guess what my question should have been is what is the
  98. Science

    Describe the procedure for preparing 250mL of buffer solution with a pH of 5.00 from acetic acid (CH3COOH) and sodium acetate. How many grams of acid do you have to mix with 3.6 grams of sodium acetate? (Given Ka for acetic acid = 1.8x10^-5)
  99. Chemistry

    You have 800 mL of a 0.050M phosphate buffer, pH 6.5. You need to increase the pH of this buffer to 7.5 by using 6.00M NaOH. Determine the volume of NaOH needed. What will be the final concentration of the buffer?
  100. chemistry

    A 20.0 gram sample is a mixture of sodium phosphate ,sodium mono-hydrogen phosphate,sodium dihydrogen phosphate and sodium chloride. The sample is dissolved in 100.0 ml of deionized water and titrated with 1.5 M hydrochloric acid. The initial pH of the

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