Ph Definition and 512 Threads

  1. B

    Calculating pKa when pH is known

    Heres a question involving what I'm talking about When 5mls of 0.05M CH3COOH is allowed to react with 1.5mls of 0.05M KOH. The pH is found to be 4.43. Using the Henderson-Hasselback equation calculate the pKa. My teacher told me that you can find the amount of dissociated ions of the...
  2. I

    Calculating pH for Strong Acid-Base Titration

    Homework Statement The problem is as follows: 100.0 ml of 0.100 M acetic acid is placed in a flask and is titrated with 0.100 M sodium hydroxide . An appropriate indicator is used. Ka for acetic acid is 1.7 x 10 -5. Calculate the pH in the flask at the following points in the titration. a...
  3. E

    Calculating pH during Titration: How to Factor in Volume and Dilution?

    Homework Statement 100.0 ml of 0.100 M acetic acid is placed in a flask and is titrated with 0.100 M sodium hydroxide . An appropriate indicator is used. Ka for acetic acid is 1.7 x 10 -5Calculate the pH in the flask at the following points in the titration. a. when no NaOH has been added...
  4. N

    Simple pH Problem (If I could remember)

    Homework Statement If one mixed 100mL of .1M Sodium acetate with 100 mL of .1M acetic acid, the pH of the solution would be 4.7 If 60 mL of .1M NaOH were added to this solution, what would be it's pH? Homework Equations Henderson Hasselback pH=pKa+ log(base/acid) The Attempt at a...
  5. D

    Titration of Sr(OH)2 by HCl. What is the pH?

    1. COnsider the titration of 80.0 mL of 0.100 M Sr(OH)2 by 0.400 M HCl. Calculate the pH of the resulting solution after the following volumes of HCl have been added. a. 0.0 mL b. 20 mL c.80 mL Homework Equations Henderson–Hasselbalch equation or direct -log The Attempt at a Solution a) before...
  6. D

    Calculate pH of Buffer Step-by-Step Guide

    I have no idea how to find the pH of a buffer solution: Please step by step! Calculate the pH after 0.020 mol NaOH is added to 1.00 L of: a mixture containing 0.100 M HONH2 and 0.100 M HONH3Cl please step by step instruction so I can follow and do other problems on my own! Thanks
  7. N

    PH concentrations, strong acids and water

    Hello! I was wondering, with questions such as "What is the pH of 0.05 mol dm-3 of HCl?", you specify the pH by simply using the concentration, as it completely dissociates. However, I assume that at such a concentration like this it is not 'pure', and would be present in water. Shouldn't I...
  8. J

    Effect of ph on uv absorbance of benzoic acid

    i was recently reading about uv absorbance, and i understand why species such as the phenoxide ion and aniline absorb uv radiation at longer radiation and with more efficiency than their protonated counterparts. i have spent long hours, however, trying to figure out why a benzoate ion might...
  9. C

    Calculating pH of Limestone Quarry Water | H2CO3 pk1=6.37, pk2=10.32

    Homework Statement Find the pH of water in limestone (CaCO3) quarry. H2CO3 pk1=6.37, pk2=10.32 Homework Equations pH=pKa + log [conjugate base]/[acid] Kw=10^-14 The Attempt at a Solution CO3 2- + H2O -> HCO3- + OH- Ka= [HCO3-][OH-]/[CO3 2-] 10^-10.32=x^2/[10^-6.37] [OH-]=x=.01059...
  10. M

    What is the pH of a 1% sulfuric acid solution?

    Can anyone tell me what a 1% (mass or volume) sulfuric acid solution is in moles? I want to find out the pH of a 1% (mass or volume) sulfuric acid solution?
  11. S

    PH of saturated solution of CaCO3

    how do u calculate the pH of a solution of CaCO3(s) in 1.0 M NH4Cl?
  12. N

    What factors are important in designing pH electrodes and metallic electrodes?

    [FONT="Palatino Linotype"]I have not searched enough/researched, but my immediate need is to clarify the following in the context of pH electrodes, metallic electrodes and conductivity cells, particularly as regards the way they are conceived/ designed, [WARNING] my queries may be naive...
  13. Z

    Solve Polyprotic pH Problem: K2HPO4 & H3PO4 (65 Chars)

    A .05 M sample of K2HPO4 was dissolved in 800 mL of water, and the pH was adjusted to 7 by using a 1 M solution of H3PO4 followed by water bringing the volume up to 1 L. How many mL of H3PO4 were added? (On this problem charge and mass balance have to be used.) My problem is just in the...
  14. M

    What is the pH after adding a base?

    This is my question: When a 17.9 mL sample of a 0.493 M aqueous nitrous acid solution is titrated with a 0.476 M aqueous barium hydroxide solution, what is the pH after 13.9 mL of barium hydroxide have been added? I'm not really sure how to start it? I have the moles of the acids and the...
  15. W

    Calculate the pH of 20.00 mL of 0.20 M KHP

    Homework Statement Calculate the pH of 20.00 mL of 0.20 M KHP. Given: pKa1(H2P)= 2.950 pKa2(H2P)= 5.408 Homework Equations k = [H][P]/[HP] The Attempt at a Solution I used this equation and got: 3.91e-6 = [x][x]/[.2] x^2 = 7.82e-7 x = 8.8e-4 = [H] pH = 3.05...
  16. M

    Calc pH of Rainwater w/ SO2: 1ppm in Polluted Air Mass

    Homework Statement Calculate the pH of rainwater in equilibrium with SO2 in a polluted air mass for which the sulfur dioxide concentration is 1ppm. SO2(g) +H2O(g) = H2SO3(aq) Kh=1M/atm H2SO3 = HSO3- + H+ Ka=1.7x10-2MHomework Equations The Attempt at a Solution I'm pretty lost for this one. I...
  17. S

    HCl + Mg = decrease in pH? Why?

    I did an experiment today, I put some magnesium in HCl solution (pH of around 1 or so) , but for some reason the pH decreased (turned more acidic), and my teacher said that's expected but didn't tell me why it happens. Enlighten me, please.
  18. S

    [H+] and pH of 100 mM solution of KOH

    Homework Statement What is [H+] and pH for a 100 mM solution of KOH The Attempt at a Solution This seems very simple..its only 2 marks but I don't know what I'm doing wrong. I understand KOH will dissociate into K+ and OH- pOH=-log(OH) ? ph + pOH = 14 p[OH]=-log[100x10^-6?]...
  19. S

    Biochemistry pka and pH relationship

    Homework Statement If a solution of a weak acid contains more HA than A-, then Homework Equations - The Attempt at a Solution the answer is pH > pKa. Okay my question is why is this the answer. I'm trying to understand in what situation you would have the pH greater or less...
  20. S

    Troubleshooting pH Levels in Saltwater Aquariums

    I have been trying to raise the pH of sand filtered salt water. I tried sodium bicarb but have been getting a thick precipitate. I am trying to raise the pH to 9-9.4 It starts out at around 8.2. I have also tried NaOH and have had no luck maintaining the pH at 9-9.4 Any advice would be much...
  21. S

    Concentrations of conjugate bases at specific pH levels

    The pKa for the dissociation of H3PO4 is 2.15. What is the concentration of H2PO4-1 (in M) at pH 3.21 if the original concentration of the phosphate was 2.37 M? My Attempt: Key Information: pH final: 3.21 Initial Molarity of phosphate: 2.37 M pKa: 2.15 I started with the first...
  22. L

    K_sp ; increasing pH with given [OH]

    1. State the Problem A water initially contains 40 mg/L of Mg2+. The pH of the water is increased until the concentration of hydroxide ions (OH-) is 0.001000 M. What is the concentration of magnesium ion in this water at this pH? Give you answer in milligrams per liter. Assume that the...
  23. P

    Protein pH titration (Henderson-Hasselbalch)

    Homework Statement A solution of histidine has all acid-base groups protonated. The pKa of the carboxy group is 1.8, the amino group is 9.2, and the side chain is 6.0. For each mole of amino acid, 2.5 moles of NaOH are added. What is the pH of the solution? Homework Equations...
  24. K

    Testing pH Change of Na2CO3 Solution After a Month

    Does anyone know if a Na2CO3 solution will change in pH when you leave it for a month? Will the pH go up or down? I thought maybe the CO2 would escape which would make the pH go higher?
  25. F

    Solved: Calculate pH of Aqueous Solution w/ HBr(g)

    [Solved] pH of Aqueous Solution Homework Statement Calculate the pH of the following aqueous solution prepared by adding 3.0L HBr(g), measured at 27 degrees Celsius, 757 mmHg pressure, to sufficient water to give 0.10L of solution. Homework Equations pH = -log[H+] The Attempt at a...
  26. V

    How to Calculate PH and POH when Adding Solid KOH to HCL Solution?

    1. Calculate the PH and the POH of the solution obtained by adding .2g of Solid KOH to 1.5 liters of .002M HCL Homework Equations 3.I understand this is a mol/ liter question. but I just don't understand how to transfer .2g of koh to ml and to find the concentration. I know PH= - log...
  27. S

    Disable the effect of HCl on the PH of solution?

    Hi, well my friend is in the final year graduation and he is working on a project a part of it is trying to detect the pH of a certain compound exist in acidic HCl solution, this compund don't remember its name for recent but it has the amino 'NH2" group this compund is in solution of HCL and...
  28. G

    Calculating the pH of a HCl-NaOH Mixture

    A solution which is formed by combining 200. mL of 0.15 M HCl with 300. mL of 0.090 M NaOH has a pH of ____ ive worked out concentration of H ion is 0.03 and the concentration of OH ions 0.027. but i don't know what to next? answer is 2.2 thanks
  29. G

    How Do You Calculate Formate Ion Concentration and pH in Mixed Solutions?

    Homework Statement calculate the formate ion concentration and pH of a solution that is 0.05m in formic acid (HCOOH;Ka=1.8x10^-4) and 0.10M in HNO3. hey guys just wondering how the equation goes?? like this?? HCOOH + HNO3>>?
  30. G

    Help Solve PH Homework: NaOH + H20 at 25degrees

    Homework Statement We add 0.535 g of NaOH to 100.0 mL of water at 25degrees. What is [H3O+] in this solution at 25degrees? hey guys, I've practiced these types of questions alot, but I've never came across one like this before. i tried writing equations and i got this 2NaOH+2H20>>2Na+2H30...
  31. G

    How Do You Calculate the pH of a Diluted HNO3 Solution?

    hey guys, I've just started PH, just wondering if you could show me how to do this question. thanks for any help What is the pH of a solution made by mixing 800 mL of 0.01 M HNO3 and 700.75 mL of water?
  32. G

    Solving pH of an Aqueous Solution of Weak Acid HCOOH

    Homework Statement hey guys, I've got a prob, i kinda know how to do this question but i can't get past the first step. i want to write an equilbrium expression by I am not sure what the chemical reaction is. any help would be good Homework Equations A solution of a weak acid, HCOOH...
  33. D

    Calculating base ionization constant from a known pH and concentration

    Homework Statement In this experiment you will find the ionization constant for ammonia, a weak base. I have completed the experiment, and have the following: Initial concentration of NH3: 3.708mol/L Initial pH of NH3: 10.26 Homework Equations NH3(aq) + H2O(l) <--> NH4+(aq) +...
  34. K

    Finding pH given molarity and volume

    Homework Statement If 50ml of 0.004M H2CrO4 was combined with 50 ml of 0.005M HNO3 what is the pH of the resulting solution? Homework Equations Moles H3O=Moles OH ? Formula for KA The Attempt at a Solution So, here's what I have so far. I made the H2CrO4 represent the acid...
  35. P

    Solution check for pH of Strong Acid and Strong Base

    Homework Statement Calculate the pH after 24 mL of 1.00 M NaOH is added from the burette to a beaker containing 25.0 mL of 1.00 M HCl Homework Equations pH = -log [H+] 1*10^-14 = [H+][OH-] The Attempt at a Solution combined volume = 49mL n.unreacted(H+) = 0.025-0.024 = 0.001...
  36. E

    Is the Final pH Calculation Correct?

    Homework Statement What will be the final pH of the solution if a drop (approximately equal to 1/20 mL) of 1.0M HCl is added to a 10mL 0.1 M CH3COOH sol'n? Homework Equations pH = -log [H+] The Attempt at a Solution I first determined the number of moles of H+ from the partial...
  37. O

    Titration of HBrO: Calculating pH of KOH Volumes

    Homework Statement Consider the titration of 20.0mL of a 0.100 M solution of HBrO, a weak acid (Ka=2.5x10-9) with 0.200 M KOH. Calculate the pH of the following volumes of KOH. a. 0.00mL b. 5.00mL c. 10.00mL d. 30.00mL Homework Equations pH=pKa +log [base]/[acid] The Attempt...
  38. A

    Calculating pH & pOH of AgNO2 Solution

    Homework Statement If 0.1g of Silver Nitrite (AgNO2; ksp = 6 x 10^-4) is added to 100 mL of water, what would the pH and pOH be? Note: The Ka for HNO2 is 7.2 x 10^-4 Homework Equations The Attempt at a Solution I really am not sure how to approach this except for the fact that...
  39. K

    At which pH does your skin burn?

    I searched up NaOH and saw that it's irritating at 0,05 to 0,5 mol/l. So I guess at a pH of 12,7 you will burn your skin. Is that true? I'm going to do an experiment with 5% NaOH. I thought it was a very small concentration but actually you could burn quite a bit with this solution after a...
  40. S

    Calculating pH of a Nitric Oxide Solution without Ka Value?

    Homework Statement what is the pH of a 4.5x10-8M solution of nitric oxide? The Attempt at a Solution well first off.. NO(aq) + H2O(l) <-------> HNO+(aq) + OH-(aq) or?......-->HNO2(aq) + H+(aq) Now I have no idea how much of the nitric oxide is actually going to react with the water. I...
  41. S

    Calculating pH, pOH, [OH-], and Kw at 37°C

    Problem: The pH of pure water at 37°C is 6.80. Calculate Kw, pOH, and [OH-] at this temperature. Work: pH: 6.8 pOH = 14 -6.8 = 7.2 [OH]: 10-7.2 = 6.3 x 10-8 M Kw= [H3O] [OH] = 1.5 x 10-7 x 6.3 x 10-8 = 1x10-14 Real answer: pH:6.8 pOH:6.8 [OH]: 1.6x10-7 Kw: 2.5 x 10-14 What...
  42. M

    The resulting pH due to the mixing of four solutions

    ive spent over 2 hours on this question and i am unable to solve it. If anyone could help it would be greatly appreciated. What is the pH of the solution that results from mixing the following four solutions together? (1) 150. mL of 0.250 M NaCl (2) 300. mL of 0.200 M HCl (3) 100. mL of...
  43. A

    Calculate the pH of a solution made by dissolving 10.6 g caffeine

    1. Homework Statement Calculate the pH of a solution made by dissolving 10.6 g caffeine (C8H10N4O2, a weak base, Kb = 4.1 x 10-4) in enough water to make 100. mL of solution. Homework Equations pH = -log [H3O+] kb = kw/ka The Attempt at a Solution I first found conc.: MM=...
  44. M

    PH of solution from mixing four solutions

    Homework Statement What is the pH of the solution that results from mixing the following four solutions together: (i) 150 ml of 0.250M NaCl (ii) 300 ml of 0.200M HCl (iii) 100 ml of 0.050M HNO3 (iv) 450ml of 0.200M NaOAc Homework Equations The Attempt at a Solution Firstly...
  45. P

    Should cadmium sulfate affect the pH of my buffer?

    I have a 0.2M solution of Sodium Acetate, (which surprisingly seems to be at pH7.8, (we calculated it should be around pH9)). We then add Cadmium Sulfate, and adjust the pH using acetic acid to pH5. However, when I add the Cadmium Sulfate the pH drops. Surely this can't happen?
  46. B

    Calculating the [H+] and pH of a lactic acid solution

    How do I calculate the [H+] fo a 0.05 M lactic acid solution. The Ka of the lactic acid is 1.39 X 10-4 is this a henderson - hasselbalch equation?
  47. P

    Sodium Acetate pH - 0.2M Solution, No Acetic Acid Added

    I have 0.2M solution of Sodium Acetate, (100ml with 1.6g NaAc) I want to work out the pH it should be. THERE IS NO ACETIC ACID ADDED. This is causing me nightmares! I am measuring ph 6.5 but apparently that is wrong. Why would that be so? Cheers!
  48. 3

    What is the pH of a Mixture of 2.00M Chlorus Acid and 2.00M Formic Acid?

    Homework Statement 2.00M chlorus acid and 2.00M formic acid are mixed. What is the pH? Homework Equations Ka of chlorus acid is 1.1×10-2 Ka of formic acid is 1.78×10-4 The Attempt at a Solution For chlorus acid with quadratic equation to find x: x²+0.011x-0.022...
  49. A

    Calculating pH of Na3PO4 and NaH2PO4 Solution with Ka Values for H2CO3

    Homework Statement 50ml of 0.10M Na_3PO_4 + 50ml of 0.10M NaH_2PO_4 For H_2CO_3: Ka_1 = 7.5 * 10^{ - 3} Ka_2 = 6.2 * 10^{ - 8} Ka_3 = 1.0 * 10^{ - 12} Homework Equations The Attempt at a Solution Since K_h of Na_3PO_4 > > Ka_2 , I considered only hydrolysis of Na_3PO_4...
  50. A

    Calculating pH of 0.1 M NaHCO3 with Ka values | Salt Hydrolysis Formula

    Homework Statement Find pH of 0.1M NaHCO_3 Ka_1 (H_2CO_3) = 4.3 * 10^{ - 7} , Ka_2 (H_2CO_3) = 5.61 * 10^{ - 11} Homework Equations pH = \frac {1}{2}(14 + pKa_1 + logC)The Attempt at a Solution Now K_h = \frac {Kw}{Ka_1} = 2.3 * 10^{ - 8} > > Ka2 So I neglect dissociation and use salt...
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