buffer

  1. C

    buffer prep for engineers

    Hi guys I need to prepare an unroofing protocol. However, I haven't made buffers since undergrad (I'm an engineering RA since 2014) and humbly ask for a reference or advice where to start... So far I have the pure powders for glucose, NaCl KCl, MgCl2 and CaCl2 ,and made an order of these...
  2. P

    How much of each stock would you need for 100 ml of buffer?

    I don't really know how to do this question - please help! You are running a biochemical assay with an enzyme that needs to maintain a constant pH of 6.6 in order to operate effectively. Using starting stock solutions of 0.2M of NaH2PO4 and Na2HPO4, how much of each stock would you need for 100...
  3. Y

    Difficult buffer question...

    Question - You will prepare 2 buffer solutions, one which is pH 5.2 and one which is pH 8.8. Solutions available: 1M NH3, 1M NH4Cl, 1M ethanoic acid, 1M sodium ethanoate solution. Calculate how much of the above solutions you need to make 100cm3 of each buffer. Use the equation pH = pKa - log...
  4. Y

    Buffer calc

    Question - You will prepare 2 buffer solutions, one which is pH 5.2 and one which is pH 8.8. Solutions available: 1M NH3, 1M NH4Cl, 1M ethanoic acid, 1M sodium ethanoate solution. Calculate how much of the above solutions you need to make 100cm3 of each buffer. Use the equation pH = pKa - log...
  5. Y

    HELP! Buffer calculation

    The question: You will prepare 2 buffer solutions, one which is pH 5.2 and one which is pH 8.8. Solutions available: 1M NH3, 1M NH4Cl, 1M ethanoic acid, 1M sodium ethanoate solution. Calculate how much of the above solutions you need to make 100cm3 of each buffer. Use the equation pH = pKa -...
  6. S

    Atomic bomb

    Is there any substance that scientist has made that can destroy ayomic bomb?:d
  7. S

    a buffer reated problem

    Calculate the H30 + (hydronium ion) concentration for a buffer solution of 2 M phosphonic acid and 1.5 M potassium hydrogen phosphate [Ka1= 7.11* 10^-3; Ka2=6.32x10^-8]. I found this problem. Firstly I feel that phosphonic acid is wrongly written, it should be phosphoric acid. Assumimng it as...
  8. JasonHerbalExt

    Which pair of solutes could be used to prepare an aqueous buffer solution with a pH <

    Which pair of solutes could be used to prepare an aqueous buffer solution with a pH < Which pair of solutes could be used to prepare an aqueous buffer solution with a pH < 7? (A) HCl – NH4Cl (B) HF – NaF (C) NH3 – NH4Cl (D) NaOH – NaCl
  9. B

    pH / buffer question

    Freshening up on acid/base chemistry and came across this problem. I can't remember how to work this. Help? One liter of a 0.1M buffer (pK=8.3) is prepared and adjusted to a pH of 2.0. (yes, you read that correctly) a)What are the concentrations of the conjugate base and weak acid at this pH...
  10. P

    pH of buffer solution

    I really don't understand much about buffer so I don't know how to solve this problem. Please help me or give me some hints to solve it. Thank a lot. Calculate the volume of 0.200 M NH3 and 0.300 M NH4Cl to make a buffer solution having pH = 10.0 Given: acid dissociation constant for NH4+ is...
  11. S

    Buffer question PLS HELP

    A sodium acetate-acetic acid buffer solution was prepared by adding 0.020 M HCl solution to 500 ml of 0.020 M Ch3COONa and then diluting the mixed solution to 1.0L. Calculate the original volume of the HCl solution needed to prepare a buffer solution of pH 5.00. The given answer is 180ml. How...
  12. K

    buffer capacity

    The buffer capacity of adding NaOH to a mixture that has a concentration of acetic acid = 1.500 M and a concentration of acetate ions = 0.500 M is... (Ka for CH3COOH = 1.75 x 10-5) Alright, so I have no idea what to do with buffer capacity we haven't covered it yet, can anyone tell me how to...
  13. C

    Calculate volume of HCl needed to change buffer pH by 1 unit???

    How do you calculate the amount of HCl needed to change the pH of a NH3/NH4+ buffer by 1 unit? There was 100mL of NH3 2M and 10.698g of NH4 0.5M and then this was mixed with 400mL of water to make 500mL buffer solution. Only 80mL of this was used for each trial. HCl was 1M. Starting pH was...
  14. S

    Acid-Base and Buffer Calculations

    Hello :) I honestly have NO idea on how to go about this calculation, it appears simple but I'm struggling, can somebody kindly go through the steps with me as I REALLY want to learn this!! What is the Ratio of [Base]/[Acid] in the following Buffer system? Information: Target pH = 9.89 AB...
  15. S

    pH Buffer Calculations

    Hello :o Can somebody PLEASE provide me with a sense on how I answer these two questions? My maths skill is not the best and I although it provides me with an equation I don't know how to use it? :confused: Q1) Refer to the attached image. The acid is Acetic Acid (CH3COOH) and the Conjugate...
  16. C

    Buffer salt

    My teacher said to write a formula of a single salt that could be used in practice as a buffer. I didn't know you could use just a single salt. Does anyone have an example? How would this work?
  17. H

    Buffer pH calculation

    I am stuck on this question.. Calculate the pH change for an acetate buffer consisting of 0.2M or sodium acetate and 0.2M of acetic acid following the addition of 5ml of 5M HCl. The pKa of the buffer is 4.75. I have calculated the original pH to be 4.75 but I am clueless as what to do next...
  18. A

    Buffer Solutions??

    So I'm in the midst of writing up a labreport for a buffer solutions lab. I've done all the work, but im skeptical of my workings, as the answers seem to not be correct.. I shall post a general list of my workings, if anyone spots something wrong please post what it is. Thanks ...
  19. S

    Buffer solutions calculations

    This the question: Q) You need 100 ml of 200 mM phosphate buffer and you have two stock solutions from which you can make the buffer; 0.8 M NaH2PO4 (the acid form) and 0.8 M Na2HPO4 (the base form). You need to add 3 times more of the acid form than the base form to achieve the desired pH. How...
  20. H

    Problem finding a suitable pH 9 buffer

    Hi everyone, I'm new here and decided to get online to glean some info from those of you with experience/expertise in buffers. I'm trying to find a buffer for pH 9 that will neither bind Cu2+ nor Zn2+, nor be included in beta-cyclodextrin, nor be insoluble in water at 25deg C. I'm making up...