Acid Definition and 698 Threads

Definition of a "Feeble" acid? I'm currently trying to re-familiarize myself with chemistry, after a very long absence of any study in this field. At the moment I'm working my way through the text "Fundamentals of Chemistry" by "David E Goldberg" and I notice the author introduces the concept...

Homework Statement In a particular solution, acetic acid is 11% ionized at 25 degrees Celsius. Calculate the pH of the solution and the mass of acetic acid dissolved to yield 1.00 L of solution. Ka of CH3CO2H: 1.8x10^(-5) Homework Equations Ka=([CH3CO2-][H3O+])/[CH3CO2H] pH=-log[H3O+] The...

Hello, on Zumdahl's Chemistry (9th edition), p.736: HCN, weak acid (Ka=6.2x10^-10), is dissolved in water. 50ml sample of 0.100M HCN is titrated with 0.100M NaOH. Calculate pH after 8.00 mL of 0.100M NaOH has been added. The steps are given. Then final answer is 8.49. That makes no sense to...

My textbook assumes that whenever K-constant of a weak acid is bigger than K-constant of water, the water should be a negligible source of H+ ions. However, how do we know that the concentration of weak acid could be too low and the H+ ions from water can actually have a significant effect?

Lead Acid Battery "Internal Resistance" and Temperature Hello, I've reached my wit's end trying to understand the theory behind charging lead-acid batteries. I believe I have read over twenty different articles, maybe six hours worth of studying. According to what I've read: Charging...

I'm having trouble understanding the following reactions we did in lab and I am not sure our data is very good. CuSO4 + NaOH yields a blue precipitate. Which I understand is Cu(OH)2. I get this. Next we add NH3 to the solution above and nothing obvious changes. I think the precipitate...

I wanted to make strontium acetate but it didn't get hot (like when I mix calcium hydroxide with acetic acid). Does that mean it didn't work?

Hi guys, I have a chemistry question which has been disturbing me. :cry: Please help me, it goes like this. A liquid, C6H12O2, was hydrolyzed with water and acid to give an acid A and an alcohol B. Oxidation of B with chromic acid produced A. The formula of the original compound is? I will...

I recently built a 3d printer that extrudes PLA or Polylactic acid for the material. When printing on a glass bed the pla drags behind the extruder because it won't stick to the glass. On the other hand printing on a sheet of acrylic the PLA sticks so well that it is difficult to remove after...

Homework Statement Let's say that i have a unknown weak acid. I prepare 10mL of the weak acid diluted in 25mL of water. I titrate the solution with NaOH. 7.37mL of NaOH was needed for a full titration. Therefore, half-titration of this acid was 3.69mL. I measure the pH of the solution with a...

Hi, we just moved our acid cabinet to a different floor, emptying it out during transport. I was thinking of taking the opportunity to give it a good cleaning. Any suggestions? It is a blue Flinn scientific cabinet. There is some discoloration on the inside walls and shelves. I am...

Polylactic acid (PLA) is a very popular raw material used for plastic extrusion 3d printers. Myself and many others in the 3d printing community have have experienced difficulty getting the the first layer to stick to the bed. I have tried a couple things so far 1) Heated smooth glass bed...

What does it mean that "acid is produced from ____" by bacteria? I've identified a bacteria (specifically stephococcus thermophilis) and am using Bergey’s Manual® of Systematic Bacteriology to learn more about it. The manual states S. Thermophilis produces acid from glucose, but not from...

Homework Statement How many moles of OH– are required to raise the pH of 4.00 liters of 25 mM glycine, pH 1.90, to a final pH of 9.70? Assume that the addition of OH– does not change the volume of the solution. Homework Equations I know at some point I will need to use the...

I am confused as to why this happens when magnesium is introduced into a hydrochloric acid solution: $$2HCl_(aq) + Mg(s) \rightarrow H_2(g) + MgCl_2(aq)$$ I understand that the magnesium will form an ionic bond with chlorine and then quickly dissolve. However, I don't understand why the hydrogen...

H2SO4 + H2O -> HSO4- + H3O+ A question by a noob. I get the fact that water can act as an acid and as a base. The oxygen "pulls" the hydrogen+ ion away from the sulfuric acid oxygen hydrogen bond an gets one itself and becomes positively charged, therefore a hydronium. However, I wonder...

I read that at Los Alamos they cooled plutonium and then dissolved it with sulphuric acid - would this work at Fukashima? Could the Fukashima nuclear cores be turned into liquid and then pumped out?

1. Homework Statement Fe(NH4)2(SO4)2*6H2O is mixed with H2SO4 and then titrated with KMnO4 until the equivalence point is reached. The question I am confused with is: What might have been the product(s) in the original solution if it had remained neutral? (if the solution was not acidified...

Can anybody tell me how to convert phenyl acetic acid to sodium phenyl acetate. thanks.

Homework Statement 7.39 mmol of base was used when titrating 432 mg of a monoamine monocarboxylic amino acid from pH 0.8 to 12.0. What is the name of the amino acid? Homework Equations None I suppose. Henderson-Hasselbalch perhaps, but I don't see how that helps me The Attempt at...

Homework Statement Determine the percent sulfuric acid by mass of a 1.49m (molality) aqueous solution of H2SO4. H2SO4 has a molar mass of about 98 g/mol Homework Equations Percent by mass = mass solute / mass solution Molarity = mol solute / liter of solution Molality = mol solute...

I want to know why HCl is a much stronger acid than H2O.They have similar bond energies (H-Cl = 427 kJ/mol, O-H = 467 kJ/mol), so there should be easy to ionize both. Besides, O is more electronegative than Cl, so it should "steal" the electron easier. Why is HCl Ka so superior than water Kw?

Boric acid + Isopropyl alcohol = ? Hi...I've made some ant killer solution: 4.9 grams of boric acid, 39.4 grams of table sugar (sucrose?), in 250ml water Works fine. Take 1/4 of a paper towel, fold into a small rectangle, place on inverted saucer, and saturate with ~1 tsp of...

Homework Statement Balance the following equation and write the corresponding ionic and net ionic equation (if appropriate): CH_{3}COOH _{(aq)}+ KOH _{(aq)} \rightarrow Homework Equations None as far as I know. The Attempt at a Solution I wrote: CH_{3}COOH _{(aq)}+ KOH...

Dear PF users, We know what is meant by acid number and softening point for resins. If it is mentioned as acid number is 8W60 and softening point is 130W180 °C, I am just confused what about 'W' in between those numbers.. Thanks for your reply. Regards, Rajini.

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.

So according to the rules of solubility all ionic compounds containing acetate are soluble in water. However acetic acid is a weak acid. Why is this if acetate is dissolved in water?

Homework Statement Calculate the analytical concentrations C2[KOH] and C2[H3PO4] in a solution where H3PO4 (originally of concentration 0.2 moldm-3 and volume 0.250 dm3) is titrated with KOH (originally of concentration 0.8 moldm-3, unknown volume used) until the pH reaches 7.8. Homework...

Without using a cyanide

Buffer (pH of a weak acid decreases when we add NaOH! Yes, really.. This is not homework, but just something that I find not following general rule. Just wondering why. So We have the titration of 20.0 mL of .100M HF with .100M NaOH With 0mLof NaOH, the pH=2.08 (by calculating) But...

Can somebody please tell me how to convert cinnamic acid to cinnamaldehyde? I was planning to first make it into the alcohol and then use PCC, but then wondered that reducing the acid might also reduce the α β unsaturated carbons too. Is there any reagent that would do the trick without causing...

Hi, Hydrochloric acid is the acid & water would be considered the base. Also does this mean that if there are more H20 molecules the solution would be considered a base? And if we have more HCl molecules than H20 this means the solution could be considered acidic? If so is it possible...

Homework Statement What is the concentration of acetic acid in 250mL of a 100mM acetate buffer at pH 4.76? Homework Equations Henderson Hasselback The Attempt at a Solution I used the Henderson Hasselback equation. plugged in 4.76 for pKa. plugged in .025 for the concentration of...

This may seem weird, but after a day of acid reflux here goes: Let's say you could shrink yourself down, and get swallowed alive by a healthy woman -- would her stomach be able to dissolve you bones and all? Or would you suffocate before feeling any considerable burning? Would you even feel...

Homework Statement Calculate the [OH-] concentration in a 0.5 M solution of potassium fluoride (KF). Ka for HF is 7.2 × 10−4.The Attempt at a Solution I know that KF → K+ + F-, therefore having a 1:1 ratio, [F-] = 0.5M ,but from here I am unsure what to do with the F- concentration. I know that...

Ok, quick question. I know that baking soda is great for heartburn, but why is it in certain medicines, they have sodium bicarb AND citric acid powder? My wife actually uses those two compounds to make bath fizzies. She adds esentual oils to them for health benefits and smells. haha. Anyway...

Homework Statement Lauric acid , CH3(CH2)10CO2H has been dispersed 500cm2+ on the water surface. Assume that the cross-sectional area of acid molecule to be 18.2A2+ and the density of the initial acid is 0.78gcm3-, calculate the amount of acid that dispersed on the surface of water. * the...

Homework Statement Basically I'm doing a lab report where we place copper pennies in a solution of salt and vinegar. This should strip the copper oxide off the outside of the pennies, leaving the copper underneath shiny and looking "new". The problem is why we add the salt. Homework...

Homework Statement Determine the pH at the equivalence point after 20.00mL of a 3.75 M NaF(aq) solution is titrated with 3.25 M HI(aq) Homework Equations ##k_a = \frac{[A^-][H^+]}{[HA]}## The Attempt at a Solution The first thing I noted was that NaF ##\rightarrow## Na+(aq) +...

Hey all, I have concentrated nitric acid (~70%), and I want to use it to dissolve Zr/Y metal. I've dissolved Y before, and I know it's as simple as putting metal into acid. The question I have, is there a known dissolution rate I should use to barely dissolve the metals in the acid? I...

I am a GCSE student and I am wondering why copper metal reacts with hot, concentrated sulfuric acid to produce copper (II) sulfate, sulfur dioxide, and water. Copper also reacts with hot, concentrated nitric acid to form copper (II) nitrate, nitrogen monoxide and water. Why do these reactions...

Are sulphate and sulphuric acid two different things? Does sulfate in the atmosphere lead to acid rain?

A student titrated a .4630g of unknown monoprotic acid with .1060M NaOH. The equivalance point volume is 28.70mL. a) Calculate the number of moles of NaOH used. Im pretty sure I got this one I did .1060 M X .02870L to equal 3.04E-3 mol b)how many equivalents of unknown acid were titrated...

I want to make sure I understand the relationship between OH- and COOH properly. So if the NaOH is introduced into a buffer solution of acetic acid and it dissociates does the OH- (due to it's very electronegative nature) immediately rip off the H+ from the COOH? If I want to calculate pH do...

Homework Statement A 10mL mixture of 2M HCl and carboxylic acid required 43.61 mL of .762 M NaOH to nuetralize it. Calculate the number of mols of carboxylic acid present. The Attempt at a Solution First figured out the number of mols of Naoh and subtracted the number of mols of HCl...

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...

Hi, I'm not sure what I just created. First I mixed sodium iodide with hydrochloric acid. Then to that I added a hydrogen peroxide/ sulfuric acid mixture (thinking it was just hydrogen peroxide). It seems a black precipitate is forming. I was trying to make potassium iodide using an...

Homework Statement Hi. I'm pretty much a beginner in organic chemistry and I'm just wondering something. For example, I know that HCl is a stronger acid than HF. But... then why the following happens if a have an organic acid (e.g a carboxylic acid)? According to what I see, a...

Homework Statement What salt is produced from sodium bicarbonate and citric acid? Just to be clear, this isn't actually homework. I would hope no professor would ever be so hard. I'm not even in chemistry. Although I did take it last year in high school. Homework Equations I really...

Homework Statement Why does a 12mol/L solution of HCl used to clean rust off iron get a brown coating after being exposed to air and washed with water, while the same concentration solution of phosphoric acid takes a day to have an apparent brown coating. Homework Equations Explain the...