Ph Definition and 520 Threads

Homework Statement If a weak acid, HA, is 3% dissociated in a 0.25 M solution, calculate the Ka and the pH of the solution. Homework Equations pH = (pKa - log[HA])/2 The Attempt at a Solution Honestly, I'm not even sure where to start. I don't have the pH or the pKa - how am I...

Homework Statement I understand that pH is a measure of the concentration of hydrogen ions in a solution. A more concentrated acid would have more hydrogen ions in a given volume of solution? Wouldn't that mean that it should have a much lower pH? Why then do we have the pH of dilute...

Hi forum goersI'm reviewing some coursework for my General Chemistry class and cannot seem to find a reasonable explanation of why amino acids exist as zwitterons in solid state and ph7 solutions. I'm fairly certain the explanation has to do with its solubility in water, but I am not sure. Here...

What do Ph. D student's learn after a bachelors? I mean, I understand that a Ph. D is research oriented, but what do you learn, what would you research? I'm curious about the field and was wondering if there were any Computer Science Grads who could help me out with this, from a first hand...

Homework Statement Hi just a quick question. I was doing a lab report and this enzyme is supposed to work between the pH of 6.7 and 7. So I had solution of .0125 N and I said OK just subtract this from 7.0 and say that is the new Ph. So for instance 7.0 -0.125 = 6.98 I said OK this is...

Hi! I've been struggling with this for hours now, but my head doesn't seem to work properly... Homework Statement Aniline, C6H5NH2, is a weak base and reacts with water, forming the phenyl ammonium ion C6H5NH3+ and OH-. Kb at 25oC is 3.2 \cdot 10^{-10} a) What is the equilibrium...

The definition of the pH and pOH of a substance is the negative log base ten of the concentrations of hydronium and hydroxide, respectively, in one molar of that substance. Right? I know I can talk about the pH of 3 mols of a certain substance in a liter of water (the pH of 3 molar of that...

Homework Statement Ok, so, I've been thinking about this for a while now. When I was doing titration back in high school, we had to put water (so that the solution would have a larger volume to work with) in the acid in which we were going to pour base from a buret. Now, my question is...

Homework Statement I'm stuck on these two problems: A) IF you make a 50 mL of a 0.1 M Tris solution (in acid form), what will be the pH? B) If you add 2 mL of 1 M NaOH to the above solution, what will be the pH? Homework Equations pH = pka + log [A/HA] Hendersen-Hasselbalch The Attempt...

Homework Statement Calculate the pH of 5.0 x 10^-8 M HCLO4. What fraction of the total H+ in this solution is derived from dissociation of water? Homework Equations The Attempt at a Solution The only thing I know to do is take -log(5.0 x 10^-8) .

Homework Statement If a solution containing a heavy concentration of hydrogen ions(i.e., a strong acid) is diluted with an equal volume of water, by approximately how much is its pH changed? (Express (pH)diluted in terms of (pH)original.) Homework Equations I think the question...

Homework Statement I'm working on a practice exam and we have a question asking us to choose the solution that has the lower pH (most acidic). a) 0.1 M NaNO3 or 0.1 M KCH3CO2 b) 0.1 M NH4Br or 0.1 M NClO4 c) 0.1 M Fe(NO3)3 or 0.1 M CaCl2 d) 0.1 M NH3 or 0.1 M NaI e) 0.1 M NH4CH3CO2...

Homework Statement We have the buffer Tricine 0.1M and pKa=8.15 and the pH=8.8 Homework Equations what are the molar conc. of tricine+ (the protonated form of tricine) and tricine0 (the deprotonated form of tricine)? The Attempt at a Solution Well, if you go to henderson-hassalbach...

Homework Statement Which solution will have the lowest pH? a) Mg(NO3)2 b) Ca(NO3)2 c) Al(NO3)3 d) KNO3 e) Zn(NO3)2 Homework Equations None I know of. The Attempt at a Solution My reasoning was that when the metal dissociates from the nitrate, it will leave a negative charge...

Hello, I've measured the pH of a med containing sodium citrate, potassium citrate and citric acid, why was is slightly acid if sodium citrate is basic ? How can I measure the pH of a non acquous solution using litmus paper ? Does some compund is, for example, basic when solid and became acid...

Homework Statement A student sets out to make a buffer solution. The student measures out 27 cm3 of 0.050 mol dm-3 HA solution and reacts with one-third of the volume of 0.10 mol dm-3 sodium hydroxide needed for complete neutralisation. (i) Calculate the volume of sodium hydroxide that the...

Homework Statement Find the pH in 50.0 mL of 1.00M HCl + 50.0 mL of 1.00M HF Homework Equations None to speak of really... The Attempt at a Solution I figured out [HCl] and [HF] in the solution: they're both 0.5M. I have absolutely no idea what to do at this point... Thanks.

Test question: "Water has pH of 7. Which solution has a [H+] concen.." 1. 2. First of all, increasing [H+] concentration will give something more acidic. Since every jump between pH numbers is a 10 fold difference, I thought that to make a 100 fold difference, you would have to do...

Homework Statement Hello guys. We are given a hypothetical data table and this is pretty much what it contains. It tells that when an iron nail is submerged in various aqueous solutions, the following observations were made. We are to give explanations to each why these things were observed...

SA + SB always give pH= 7 even if concentration of SA is a lot bigger than SB? let's say 10 M of HCl react with 0.1 M of NaOH, is the pH at equivalence point also 7?

If 25.00 mL of 0.20 mol/L HCO2H(aq) is titrated with 0.26 mol/L NaOH(aq) determine the pH at halfway to the equivalence point. So far I have: Moles of HCO2H = 0.005 mol; at half way = 0.0025 I don't know the next step.

Hello! If I have 100,000 litres of water at a pH of 8. How much NH3 at a concentration of 25%, pH >13 would I require to bring total pH to 9 or greater. An approximate figure would suffice if anyone can help. Thanks in advance.

i am interested in discussing about the pros and cons of having a vesicle of ph sensitive polymer (with drug to be delivered inside it), inside a vesicle of thermosensitive polymer for drug delivery. This gives us dual control capabilities that is temperature and ph based trigger...

What should be the molarity in an aquatic dissolution for Trimethylamine, ##(CH_3)_3N## if ##pH=11,2##? ##(CH_3)_3N+H_2O \rightleftharpoons (CH_3)_3NH^++OH^-##, ##K_b=6.3 \times 10^{-5}## I know that ##pH+pOH=14 \rightarrow pOH=2.8##, then ##[OH^-]=1.58 \times 10^{-3}## And...

Hi Everyone, First of all, I'm not a scientist ;) But I'm doing some experimentation and just want to confirm if I am on the right track. FDA pickle recipe for non fermented pickles has the following parameters: 50% vinegar 50% water I am using standard commercial 5% distilled...

Homework Statement A solution is prepared by mixing 200 mL of 0.2 M CH3COOH with 100 mL of 0.1 M of NaOH solution.Calculate the pH of the solution.(Ka=1.8x10^-5) I really don't know how to start this, so please help me.Its going to be a similar one on my exam tomorrow. Thanks.

A solution is prepared by mixing 200 mL of 0.2 M CH3COOH with 100 mL of 0.1 M of NaOH solution.Calculate the pH of the solution.(Ka=1.8x10-5) I really don't know how to start this, so please help me.Its going to be a similar one on my exam tomorrow. Thanks.

1. If the statement ph=-log([H+] is true, then how come a solution can be acidic when carbonate is present? I have been told that even if carbonate does not accept H+ the solution will still be basic just by the presence of CO3(2-)? The confusion is this: ph only depends on [H+] then how come...

Homework Statement A 0.0200 mol/L acid solution has a pH of 2.347. Calculate the percent ionization of this acid. Calculate the Ka of this acid The Attempt at a Solution I first calculated the hydronium ion concentration: 10^-pH = 10^-2.347 = 4.5*10^-3 I then used this concentration...

Homework Statement Calculate the pH of a solution that is .20M NH3 and .35M NH4Cl with a Kb(NH3)=1.8x10^-5 The Attempt at a Solution So first calculated the M of OH- produced by the NH3, [OH-]=√((1.8x10^(-5))x.20) = 1.9x10^-3 Since NH4Cl will dissociate in H2O it will leave NH4+...

Hey, I am trying to figure out some research for a department at school, and need some chemistry info. Basically, I am comparing D2O (Heavy water) HDO (Semiheavy water) and H2O (Light water) NOW... each of them have different pH levels. What does that mean that they each have...

okay well basically this is what i know or think i know: i have the pKa's of the carboxyl, amino, and R group of the amino acid and the pH of the solution it is in. I'm supposed to figure out the net charge for it at different pHs. i taught myself one way to do it (by looking **** up) and i...

Homework Statement Calculate the theoretical pH of each solution. The first solution was 30.00 mmol of HOAc (acetic acid) and 53.00 mmol of NaOAc. There was no water in this solution. Homework Equations We have to use this equation. The Attempt at a Solution I'm unsure of what...

Homework Statement If the pH of a natural water is 7.8 and the alkalinity was measured to be 125 meq/L, determine the following: -Alkalinity as mg/L CaCO3: Answer = 6250 mg/l CaCO3 -Approximate the total carbonate concentration CT, in moles per liter: Answer = 0.125 moles per liter...

Homework Statement The cid constants for the polyprotic acid H3AsO4 are Ka1=5x10^-3, Ka2=8x10^- 8, Ka3=6x10^-10. What is the pH of a 0.1M Na2HAsO4 solution? Homework Equations Kb = [H2A]*[OH]/[HA] mass balance, charge balance.. etc. The Attempt at a Solution Well I've tried...

[b]1. You have a .246 M HNO3 solution. You also have 213mL of a 0.00666M 2,2' -bipyridine. You want a solution with pH 4.19. How man L of .246M HNO3 do you add to the 213mL other stuff? [b]2. pH=pKa+log[A-]/[HA] also, pKa of 2,2' -bipyridine is 4.34 I think. [b]3. pH=pKa+...

Determine the equilibrium pH of aqueous solutions for the following strong acids or bases: (a) 257mg/L of HSO4- ; (b) 10nM NaOH ; (c) 75ug/L of HNO3

Homework Statement A strong base cane be assumed to be fully ionised in dilute solution. Use the Kw value to calculate the hydrogen ion concentration and hence the pH of a 0.15 M solution of potassium hydroxide, KOH.Homework Equations The Attempt at a Solution Problem is, I don't know where to...

The rule that if the pH of solution is below the pKa of a molecule then that molecule will be protonated is a handy rule. However, I'm finding it difficult to find the pKa of the chemicals I'm working with. This mostly applies to looking at nitrogens in organic compounds. For example, it is...

Homework Statement what do the H+ ions do to the CO3 in the CaCO3? this is a report on ocean acidity and i need help to explain what H+ ions do to the CO3 in CaCO3 Homework Equations The Attempt at a Solution please help!

I need someone to tell me if I did this right... What volume of 10N NaOH should be added to 0.1L of 1 M sodium acetate pH 5.5 to change the pH to 6.0. so I'm assuming that there is also an amount of acetic acid in this solution for it to have an acidic pH right? So is it a buffer? In which...

Pollution from fireworks occurs in a number of ways, one of which is the release of gases such as carbon dioxide (CO2) and sulfur dioxide (SO2) into the environment. These gases react further in the atmosphere to produce carbonic acid (H2CO3), a weak acid, and sulfuric acid (H2SO4) a strong...

Homework Statement Given that high concentration of urea break all bonds except covalent bonds in protein molecules.Which level of protein would remain unchanged when a protein is treated with urea? Homework Equations The Attempt at a Solution tertiery protein why is it...

A flask contains 500 mL of an acid with a pH of 4. If 500 mL of water is added, what will the pH of the new solution be? I don't want to know the answer please* I'm just wondering if it is as easy as adding the two pH's ie. 7 + 4 or do I have to work out the H+ of each ie. 10-7 and 10-4...

Hi all. New to the forum & 1st post. I've recently been put in charge of using a corrosion chamber (Ascott 450+XP) in my place of work and I've not had much experience using them. We are validating the equipment to BS EN ISO 9227:2006 (pretty much exact same as ASTM B117) using steel...

This is something I've been wondering for a while, but I thought that the inputs for things like ln(x), e(x), sin(x), etc. had to be unitless. Then how come concentration, which has units of moles per volume (or I guess just per volume, since moles are just a number? I've never been sure about...

Calculate the pH of a 0.0253 M aq solution of a monoprotic acid. The Ka for the acid is 1.79 x 10-2 So a monoprotic acid will have the form HA --> H + A, correct? I 0.0253 0 0 C -x x x E (0.0253-x) x x EDIT: I just realized the...

The first time I came across a chemistry problem about the pH of a solution that's been diluted, I thought there was an argument for a change and for no change. After doing some searching online, it seems that the pH does change since [H3O+] changes, which I understand. However, using the...

Hi, I'm currently following this lecture: Here is the script I downloaded up to the point were I got lost: It seems to be a simple combinatorics problem looking for the possible combinations of the N subsystems for a given set of occupation number n_i (how many subsystems are in state...

A solution is prepared to be 0.1475 M in Sr(OH)2. Find the [H3O+], [OH‐], pH, and pOH. I'm not quite sure where to go from here. I was thinking I can start by writing out the net ionic equation: Sr(OH)2 → Sr2+ + 2OH- But I don't really know how that helps me. Any insights?