Ph Definition and 520 Threads

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?

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?

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!

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...

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...

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...

Homework Statement Consider 1L of a solution that is 0.100 M in acetic acid and 0.100 M in sodium acetate. What will the pH be, when 0.0900 mol of sodium acetate are added? Ignore changes in volume. acetic acid pka = 1.75 E-5 Homework Equations HA --> H+ + A- pH=pka +log A-/HA...

Chemistry pH problem help please NaOH and HCl Calculate the pH after the following total volumes of .32M HCl have been added to 25 mL of 0.16M NaOH a. 0 mL c. 12.4 mL e. 12.6 mL b. 1 mL d. 12.5 mL f. 15.0 mL A. i have answered correctly but i...

Hi all, Long time lurker, very seldom poster. I have a need for an aqueous soluble compound that will thermally decompose or oxidize to form acidic products in the temperature range 100-300 C. It's well known that, on the other end of the scale, urea is water-soluble and near-neutral pH at...

Homework Statement We have two solutions: One solution that has 0.300 L of 0.100 M acetic acid, and the other with 0.100 L of 0.200 M CN^-. We mix the two solutions. At equilibrium, what is the pH of the resulting solution? Homework Equations For acetic acid, K_a=1.8*10^{-5} For CN^-...

Homework Statement The pH of pure water is temperature dependent, for example it is 6.55 at 50 C. Determine ΔG° for the ionization of water at 50C Homework Equations ΔG=ΔG°+RTln(Q) at eqm ΔG=0 q=Keq pure water: pH 7.00 at 25C The Attempt at a Solution Not sure if the process...

Homework Statement To 25.000 mL of distilled water in a 50 mL beaker, you add exactly 19 drops of 0.100 M HCl and swirl to mix. If exactly 20 drops of HCl are required to make 1.000 mL Homework Equations Calculate molarity of the diluted HCl and pH of the diluted HCl The Attempt...

Homework Statement Calculate the pH of concentrated hydrochloric acid if this solution is 24.8 % HCl by weight and has a density of 1.16 g/mL. Homework Equations The Attempt at a Solution \the percentage is throwing me of, can someone explain what it is?

Homework Statement How would you prepare 5.00 L if an aqueous solution having a pH = 10.70, if you had a supply of 0.250 M NaOH? Homework Equations I don't even know anymore... The Attempt at a Solution I've tried a million different ways but I never come up with the answer...

Homework Statement Calculate the pH after 0.030 mol NaOH is added to 1.00 L 0.100 M HC3H5O2 and 0.100 M NaC3H5O2 Homework Equations Ka=[H+][A-]/[HA] pH=-log([H+]) or 14-pOH=ph The Attempt at a Solution HC3H5O2 <-> H+ + C3H5O2- NaC3H5O2 <-> Na+ + C3H5O2- I know that Na+ has no...

technically it is not homework, more like struggling with textbook material, but something tells me it would end up here anyway so here it is : there's something about the method that gives me different results using different paths so I'm going to show both of them and see if you can spot the...

I need to know whether, given the actual composition of a synthetic fluid (in water) stated as concentrations of Na, K, Cl, urea, NH4, phosphate, citrate, and creatinine a resulting pH can be computed from first principles given the involved pKs - 3 for phosphate and citrate, one for creatinine...

Homework Statement The pH of a 1.00x10-8 M solution of HClO4 is Homework Equations -log(H3O+) The Attempt at a Solution I thought I could just do -log(1.00x10^8) = 8, but the answer is actually 6.98. Why? Does it have anything to do with it being a strong acid?

Homework Statement This question is for a lab write up. We prepared a 0.1 M citrate buffer with pH 4.0, we then diluted our buffer with deionized water 20 fold and then 50 fold. The subsequent changes in pH are as follows, 20 fold pH = 4.10 50 fold pH = 4.14 This confuses me because I have...

A Compound (not specified) has 2 ionizable groups. One is at pKa 4.2 and the other pKa is between 7 and 10. If you have 10.0 mL of a 1.0M solution at a pH of 8.17 and you add 10.0mL of 1.0M HCl which changes the pH to 4.2 what is the second pKa? I tried working this problem out a few...

Homework Statement Solid Na2HPO4 is dissolved in water. What is the resulting pH of the solution? Relative pka's of phosphate derivaties are ~2, ~7, and ~12. Homework Equations No equation needed, just look at the species which phosphate would develop. The Attempt at a Solution...

I have a slurry at pH 2. How much CaO must I add to adjust pH to 9.5 Slurry is in H2SO4 medium

I am currently a high school sophomore and am pretty good in mathematics and I have a great passion for it. I'm considering studying pure mathematics in college and probably study until I get a Ph.D. in mathematics. I'm just wondering, what kinds of jobs out there are available for math phds...

For an weak acid/strong base titration, the pH at equivalence can be estimated by pH = pKa + pHtitrant/2. Can someone explain where that equation comes from? Thanks.

Homework Statement What is the pH of a solution prepared by mixing 50.0 mL of 0.300 M HCL with 450.0 mL of 0.400 M HIO3? HIO3 Ka = 1.6 x 10^-1 Homework Equations ICE The Attempt at a Solution I first converted each concentration to its new molarity by figuring out the number of...

the question is simply to determine the [OH-] and pH of a solution that is .210 M in HCO3- first of all if i can get [OH-] then i can easily get pH by converting [OH-] to [H+] and then doing the -log[H+] so that part is easy. i just cannot get [OH-] what i did was first write the...

What is the pH of .15 M methylammonium bromide, CH3NH3Br (Kb of CH3NH2 = 4.4x10^-4) I actually asked this to someone else and got this: It just doesn't seem right. To use the information given for CH3NH2 we need to first have CH3NH3 or CH3NH2 in the solution but we start with CH3NH3Br. Where...

[SOLVED] pH of buffer solution Homework Statement Calculate the pH of a solution made by mixing 750 mL 1.00 M NH4+Cl and 250 mL 1.00 M NaOH The Attempt at a Solution NH4+ will react with H2O to form NH3 and H2O+. If my calculations are correct, [H+] after the reaction will be 2.07E-5...

Homework Statement Glycine which has a pKa of 9.6 can exist in protonated form (-NH3+) or as the free base (-NH2) because of the reversible equalibrium R-NH3+ <------> R-NH2 + H+. How much 5 M KOH must be added to 1.0 L of 0.1 M glycine at pH 9 to bring the pH to exactly 10? Homework...

Homework Statement Concentration of acetylcholine (ACh) determined from pH change after hydrolysis. Sample incubated with acetylcholinesterase is quatitatively converted to choline + acetic acid which then dissociates to acetate + H+. A 15mL solution has unknown amount of ACh with pH 7.65, and...

[SOLVED] pH question... i'm writing a research paper on the organic medicinal massage oils. i need to know the chemical composition of citric acid and it's pH. can anyone help me?

What do you do when the pH is given, but you have to find the molarity?

Hi, I have the following problem: Calculate the pH of a 0.200M Sodium Cyanide solution. I'm confused because this salt has no H or O atoms in it. How could it affect the pH of a solution? What formulas would I need to solve this? My final is tomorrow and I'm really worried. Thank you for...

This was just a curiosity thing, but... I assumed "5% acidity" to mean 5 percent of the soln was acetic acid, by volume (though, doing the calculations for "By mass", I got roughly the same pH). Also, I couldn't find the density of acetic acid in my textbook, so I assumed it was close enough...

Hi, Did my A2 biology coursework. I compared the rate of hydrolysis between pepsin 2.8 and 7.0 using milk protein. Pepsin works in the stomach, so should have a faster hydrolysis rate in the acidic pH value. But when I measured transmission percentage I got a mean of 9% for 2.8 and 15 for 7.0...

Homework Statement If you mix 200mL of a 1.8M HCl solution with 300mL of a 1.16M NaOH solution, what will be the pH of the solution? The Attempt at a Solution Well I am really lost with this problem. I am pretty sure you need to convert each to moles. .2L HCl x 1.8moles HCl...

Homework Statement The concentration of Ca2+ in hard water can be determined by titration with a reagent X which forms a complex with Ca2+ giving a change in colour. Since the colour change is sensitive to pH, the titration has to be carried out in an alkaline buffer. Th structure of X is...

"By taking a little apple cider vinegar before a meal, you can increase stomach acidity and thereby improve digestion and nutrient uptake. " But since vinegar is less acidic than stomach acid wouldn't it follow that vinegar would reduce stomach pH? (unless the watery contents of vinegar flux...

Homework Statement A mixture containing 500ml of .1 M HC3H5O2 (acetic acid) and 500 ml of .1 M NaC3H5O2 what is the pH?Homework Equations can someone walk me through this? i know the answer is 4.89 but I am not sure how to get that. I am not even entirely sure how to set up the equationThe...

What is the concentration of Ba2+ in a saturated BaCrO4 solution?

You want to make an acetic acid/acetate buffer, pH 5.6, with a volume of 250 mL, and a final concentration of ([AcOH] + [Aco-]). You may only use acetic acid and sodium acetate( no strong acid or base). How many mL of glacial acetic acid would be needed( d=1.05g/mL)?

Homework Statement Titrating .1006M CH3COOH with .2012M NaOH. pKa=4.74, Ka=1.8*10^-5 What is the pH at the equivalence point of the titration? Homework Equations pKa = -log(Ka) pH = -log[H+] The Attempt at a Solution Alright, after setting up an ICE table (in order to find...

Homework Statement I have to find the pH of a 8.57x10-10M HNO3 solution. Homework Equations HNO3 + H20 <--> H3O+ + NO3- pH= -log[H3O+] The Attempt at a Solution my theory was that the hydronium ion concentration would be the hydronium ion concentration in water (1x10-14 M) plus the...

Calculate the initial pH of 0.315 L of a 0.535 M NaHSO3 - 0.280 M Na2SO3 buffer.

[SOLVED] Amount of 6M H2SO4 to lower pH of pool from 7.0 to 4.0 Homework Statement A new swimming pool is filled with fresh, clean water with a pH of 7.0. The width is 25 ft, the length is 60 ft, and the depth linearly ranges from 3.5 to 9 ft. How much 6 M H2SO4 must be added to reduce the...

How can I calculate the amount of citric acid to add to a solution of a given pH, to achieve another value of pH?

Calculate the pH of the 0.30 M NH3/0.36 M NH4Cl buffer system. What is the pH after the addition of 20.0 mL of 0.050 M NaOH to 80 mL of the buffer solution? NH4+ ---> NH3 + H+ 0.36 0.30 0 -x +x +x 0.36-x 0.30 + x x...

[SOLVED] Anticipated pH of Buffer Solution (urgent!) Homework Statement Can someone verify my process here? i did a lab where i had 100 mL CH3COOH/CH3CO2- buffer solution. I have to find the pH if 100 mL of 0.0983 M HCl is added to it. In the lab i got pH of 1.72 [b]2. Homework Equations...

Homework Statement Need a little help on a lab. I have all the data for a titration of a weak acid with NaOH which includes the pH of the acid for however many mL of NaOH added. I've plotted a pH vs V NaOH added graph. From that, I plotted a ∆pH/∆V vs V NaOH added graph. From this, I found...

Homework Statement we are to use a logarithmic formula to give the ph of a substance. Homework Equations find the hydrogen content and show how to find the ph. The Attempt at a Solution i have checked the web to find a formula but am lost