Acid Definition and 698 Threads

Homework Statement When a weak acid HA is titrated 75% of its endpoint, it has a pH of 5.25. Calculate its Ka. Homework Equations Ka = [H+ ][A- ]/[HA] [H+] = 10^-pH The Attempt at a Solution I found [H+ ] from the pH to be 10^-5.25 M. From the dissociation equation of HA, we know there is a...

Homework Statement Homework EquationsThe Attempt at a Solution If 50% of the acid has been neutralised, then there is 0.05 M of acetic acid left.Using Ka $$ 1.8*10^-5 = \frac {x^2}{0.05-x} $$ I get x = 0.00094 -log(0.00094) =3.02687 =pH This is not one of the answers provided. I think I...

Homework Statement Homework EquationsThe Attempt at a Solution From what I know, to make buffer solutions you need a weak acid or base and it's salt. Non of the options has this. What am I missing? Cheers!

Homework Statement Homework Equations Henderson-Hasselbalch Equation The Attempt at a Solution Sorry for the huge picture, but the number says 0.007558 mol. Is my ICE table correct? Equation: 7.42 = 6.85 + log((0.007558-x)/x) (0.007558-x)/x = 3.715 x = 0.00160 mol H+/(0.07483 L + 0.01339 L)...

Homework Statement Homework EquationsThe Attempt at a Solution I chose C as if a strong "something" is added to a weak "something" then you won't get a strong curve. So acetic acid will be eliminated. If D or E was added, the equivalence point should have pH of 7 or less. Therefore I chose...

Hello! 1. Homework Statement Please, take a look at the problem and at my solution. Have I done it correctly and is my logic correct? How much of a 10 liter 30% acid solution must be replaced with pure acid to obtain 10 liters of a 50% solution? Homework Equations 3. The Attempt at a...

Homework Statement In the reaction with NH3, is specy BH3 a Lewis base ? Homework Equations Lewis acid = electron acceptor Lewis base = electron donor The Attempt at a Solution H electronegativity = 2.1 B electronegativity = 2.0 N electronegativity = 3 Since N-H bond is more electronegative...

I'd like to write the chemical equation for the reaction of 1 mole of ammonium hydroxide with .1 mole of formic acid. I understand that NH4OH is not ammonium hydroxide, and it is more accurate to write NH3, implying NH3 (ammonia) + HCO2H (formic acid) --> NH4HCO2 (ammonium formate) but would...

I got a question, consuming amino acid and consuming protein is the same thing right? Protein is a chain of amino acids but it does not really change their properties by becoming protein right?

Homework Statement An open cylindrical tank of acid rests at the edge of a table 2.20\cdot 10^0\ m above the floor of the chemistry lab. If this tank springs a small hole in the side at its base, how far from the foot of the table will the acid hit the floor if the acid in the tank is...

I was asked to take NaCl then add HNO3, then add AgNO3, and to write a net ionic equation... then add NH3 to the same mixture and write another net ionic equation. I have been trying between work and everything else to try to do this one. it wasn't well understood in class and now I haven't...

Hi! I work in the movie business doing Special Effects. To create smoke for some effects we use "A+B Smoke." It is simply a mix of Acetic Acid (Part A) and Ammonium Hydroxide (Part B). However, the smoke effects is created when the VAPOURS of these 2 chemicals mix in the air. The MSDS Safety...

Homework Statement Student mix four reagents together, thinking the solutions will neutralize each other. The solutions mixed together are 50.0mL of .1 M HCl, 100mL of .2 M of HNO3, 500mL of .01 M CaOH, 200mL of .1 M RbOH. Did the acids and bases exactly neutralize each other? If not, calculate...

Homework Statement 30 mL CH3COOH 0.2 M is mixed with 60 ml CH3COONa 0.1 M and then added with 10 mL HCl 0.1 M, then what is the pH of the solution ? (Ka = 10-5) A. 3 B. 5 - log 1.4 C. 5 - log 2 D. 4 - log 1.4 E. 5 + log 2 Homework Equations [H+] = Ka * [HX] / [X- ] ---- buffer [H+] =...

Homework Statement What is the % glycolic acid needed to replace 40% phosphoric acid (assuming it is weight%)? Homework EquationsThe Attempt at a Solution I tried to solve this by first converting the Phosphoric acid weight% to mol/L for the phosphoric acid (5.11 mol/L).. Since phosphoric...

Homework Statement In the materrials and methods of one article is mentioned that: A specific amount of citric acid and the catalyst sodium hypophosphite (50 % w/w, on weight of citric acid used) was dissolved in the starch solution. My question is how much citric acid and sodium...

Why is it that nitric acid won't react with copper oxide, but it will react with copper?

I drink 2-3 sparkling waters a day (La Croix). I look at the nutrition back and it contains nothing but carbonated water and natural flavors. So I think it's completely harmless. Now I am learning this "carbonated water" may be more than I think. Apparently it contains carbonic acid which can be...

Homework Statement Difference between nitric acid added to the mixture Copper Oxide + Carbon and nitric acid added to the mixture Copper + Carbon Dioxide 2. Homework Equations meteal oxide + carbon ---> metal + carbon dioxide The Attempt at a Solution When I added Nitric Acid to the mixture...

Homework Statement I found this problem online for extra practice for my AP Chem class. https://www.quia.com/files/quia/users/jpugteach/APChem/AP-Chem-Chapter-19-Graphs.pdf The problem in question is number 4. I do not understand how to solve it and why the answer D is correct. Homework...

Homework Statement Methyl red has the following structure [not listed here on this post] Ka = 5.0 * 10 E -5 It undergoes a color change from red to yellow as a solution gets more basic. Calculate an approximate pH range for which the methyl red is useful. What is the color change and the...

Hi everyone! So I have ZnBr2 and CdCl2, and I am asked to choose the most acidic one. Firstly, I do not understand why both salts are acidic... If my ZnBr2 undergoes hydrolisis, the reaction is ZnBr2 + 2H2O <------> Zn(OH)2 + 2HBr. This would mean that this is acidic as the HBr dissociates...

Dear PF Forum, Actually I want to study how antioxidant can benefit for our health. But, my understanding in chemistry is very limited. Perhaps I have to go back and study pH, first. I have read many sources in the internet. And this is one of them...

Hello, according to the lead acid battery standard equations The overall chemical reaction is: At the negative terminal the charge and discharge reactions are: At the positive terminal the charge and discharge reactions are: My Q? If we empty all liquid from old battery and add H2O...

Homework Statement If enough of a monoprotic acid is dissolved in water to produce a 0.0153 M solution with a pH of 6.31, what is the equilibrium constant, Ka, for the reaction? Homework EquationsThe Attempt at a Solution I have attempted to solve this problem using ICE tables, but keep getting...

Homework Statement what are the esters formed by: -fumaricacid and propanol? - succinic acid and butanol -citric acid and methanol and how does each one smell Homework Equations none The Attempt at a Solution I have drawn out each of the structural diagrams but i couldn't draw the esters. My...

Homework Statement [/B] NH3(aq) is a weak base with Kb = 1.8*10-5, Calculate [OH-] in a solution that is made by mixing togeather 500ml of 0.20M NH3(aq) and 500ml of 0.20M NH4CL(aq), what is the value of Ph?Homework Equations Henderson Hasselbalch: ph = Pka + log([conj.base/acid]) As well as...

Homework Statement Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as that of pure water at 20.0°C (18 torr). The volume of the mixture is 1.7 L, and its total pressure is 0.987 atm. Determine the number of moles...

The dye is Malachite green specifically. I understand that tannic acid has many hydrogen bonds making it very polar, but i don't understand how it is a mordant between a fibre and the dye. Any help is much appreciated.

Hey all! I have a silly doubt In acids and bases As you guys know The concentration of H+ ions For a weak acid Which does not undergo Complete dissociation Is given by mod H+=square root of Ka times C Where C is the initial concentration Of the acid And k is the ionization constant In the same...

Homework Statement "A 35.0-mL sample of 0.150 M acetic acid (CH3COOH) os titrated with 0.150 M NaOH solution. Calculate the pH after the following volumes of base have been added: (a) 0 mL, (b) 17.5 mL, (c) 34.5 mL, (d) 35.0 mL, (f) 50.0 mL." Homework Equations Ka = [H+][A-]/[HA] Ka = 1.8 ⋅...

How can I calculate the concentration of sulfuric acid with help of a neutralisation equation? (in mol/l or g/l) Neutralisation takes place with either NaOH or KOH. I've been searching for a tutorial for hours, but didn't find anything helpful. Could someone please explain me how to do it? I...

I've been thumbing back through my organic synthesis book to try and remember how to reduce a carboxylic functional group. I know how to do partial reduction to primary alcohols, or create aldehydes and or acyl halides. But isn't there a way to completely reduce it all the way to a hydrocarbon...

Homework Statement Consider the reaction of pyruvic acid (CH3COCOOH) into gaseous acetaldehyde (CH3CHO) and gaseous CO2, which is catalyzed an aqueous solution by the enzyme pyruvate decarboxylase. Assume ideal gas behavior only for the CO2. (a) Calculate ∆298 0 for this reaction. (b) Calculate...

Hello all. I have carbonaceous material soaking in Phosphoric acid. I'd like to anneal it under an inert environment to activate the carbon. One method used in literature involved freeze drying the mixture and annealing it as is, as opposed to filtering or centrifuging the mixture. However, I am...

Homework Statement Which side does the equilibrium favour? Homework Equations Equilibrium favours weak acid or weak base (I don't know why :frown:) The Attempt at a Solution Using the given pka values, since the reactant is the weaker acid, reactants are favoured. (Backward reaction is...

Its given in my book that Sulphuric acid displaces more volatile acid from Metal salts like NaCl. That is, NaCl + H2SO4→ HCl + Na2SO4 What does valtility have to do with such reactions? Or Should I just accept it as a fact?

How will increasing the molar of HCl and dissolving magnesium in it, relate to particle theory

Homework Statement An amino acid H2N-CHR-COOH e its as a dipolar ion: +H3N-CHR-COO-. In strongly acidic medium, it takes H+ to form conjugate acid +H3N-CHR-COOH 50ml solution of conjugate acid required 30ml of 0.1M NaOH to completely convert into dipolar ion. The pH of solution during titration...

What precisely is going on?

I have a rough plastic surface that I need to make very conductive. I was thinking of coating it with metal but I do not know how. Would it be possible to dissolve some copper/aluminum/nickel (or others) in acid and then pour the acid on the surface and let it dry? Would that give me a metal...

I have a piece of equipment that was manufactured using direct metal laser sintering made of a titanium alloy (Ti-6Al-4V). It is a cylinder with thin helical channels that is located above a vapour source in vacuum. I plan to coat it with silver, and I am looking for an effective way to...

Hi guys, my name is ferdinand. I'm curious about HSAB, especially to predict where the reaction goes. Exp: HI + NaF >>> HF + NaI H is hard acid I IS soft base Na is hard acid F is hard base, and HF Is hard.hard NaI Is hard soft. The reaction will goes to right or left? And why? And since hard...

They both produce H+ right? How do I tell the difference in a reaction?

So I am doing a titration with NaOH and oxalic acid, prepared by adding 14g of the NaOH to 5dm^3 of H2O, the acid is (COOH)2.2H2O (2.5g in 0.25dm^3) . I seek to calculate the percentage purity of the NaOH. Now I'm confused, usually the percentage purity is based on products?? As in you have to...

Hello, kind of focusing on the hydration of ethene/ ethylene, but how to liquid catalyst work if the reactants are gaseous? Does the acid catalyst also need to be gaseous if it is to work correctly?

Consider the following reaction: 3Si3N4 + 27H2O + 4H3PO4 --> 4(NH4)3PO4 + 9H2SiO3 --> ^4NH3(g) + 4H3PO4 + 9H2SiO3 --> 4H3PO4 + ?? The phosphoric acid solution is 85%wt. In your fella's opinion, what happens to the Meta Silicic Acid (H2SiO3)? Is the solution to acidic to form a polysilicic...

Hello Everyone Please can you tell me what is the result of this reaction?? NaClO+C4H6O6>>> NOTE:This is not a homework,i did this simple reaction yesterday.

I am trying to get a better understaning of the pH of a solution containing a salt of a weak base and a salt of a weak acid. I know it depends on which equlibrium constant is greater but I am thinking more of what it is that actually happens. For example let say we have a solution containing...

Homework Statement How much does the auto - dissociation of water contribute to the pH a 10e+3M aqueous solution of sulphuric acid? Homework Equations Ka = [H30+][SO42-}/[HSO4-] = 1.1e-2 Kw = [OH-][H30+] The Attempt at a Solution Sulphuric acid is a strong acid in the first hydrolysis step...