Questions tagged [acid-base]

This tag should be applied to questions concerning acid and base reactions. An acid is capable of donating a hydron/ proton (Brønsted acid) or capable of forming a covalent bond with an electron pair (Lewis acid). A base on the other hand is a chemical species/ molecular entity having an available pair of electrons capable of forming a covalent bond with a hydron/ proton (Brønsted base) or with the vacant orbital of some other species (Lewis base).

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49 views

Why is solubility of AgCN is higher in acidic buffer?

Solubility of $\ce{AgCN}$ is maximum in A) Acidic buffer solution B) Basic buffer solution C) Pure water According to me, it should not matter in which solution we are putting the $\ce{AgCN}$...
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25 views

Thermodynamics of Acid Base Neutralisation

I was attempting an exam in which they questioned us about the thermodynamics of acid-base reaction. The question was this: In neutralisation reaction of a strong acid and a strong base in a ...
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39 views

Is xylene an acid?

What is the pH of xylene, and is it considered to be a corrosive substance? Specifically I am interested in how xylene might interact with electrical conductors and components, which contain copper, ...
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1answer
59 views

What is the heat of reaction of weak acid reacting with weak base compared to strong acid reacting with strong base? [closed]

My book has this line only that "weak acid and weak base reaction will produce lesser heat than constant enthalpy" of strong acid and strong base neutralization which is $\pu{-57.3 kJ/mol}$.
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22 views

pKa values for amino acid

To calculate the pI value, we take the average of the pKa values from the 2 groups that result in a net charge of 0. For that to happen, the pKa values should be at the midpoint of titration where ...
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3answers
381 views

How would a pH curve look like for titration of diluted weak base compared to concentrated one?

Let's say I take $\pu{80 g}$ of a weak base, dilute it with $\pu{50 ml}$ of water and titrate it with a strong acid. I get a titration curve. Now I take again $\pu{80 g}$ of the same weak base but ...
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1answer
73 views

What is the formula for theoretical buffer capacity for a diprotic buffer system?

According to Chembuddy, the formula for theoretical buffer capacity for a monoprotic buffer system is as follows: $$β = 2.303\left(\frac{K_\mathrm{w}}{[\ce{H+}]} + [\ce{H+}] + \frac{C_\mathrm{buf}...
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1answer
203 views

How to make aluminium monostearate?

Can I make aluminium monostearate $(\ce{C18H37AlO4};$ $\pu{344.472 g mol-1})$ by reaction between stearic acid $(\ce{C18H36O2};$ $\pu{284.484 g mol-1})$ and aluminium hydroxide $(\ce{Al(OH)3};$ $\pu{...
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1answer
38 views

How to predict whether a salt will act as an acid or as a base in aqueous medium? [closed]

How to would we know if a salt such as $\ce{CO_2}$ reacts acidic or basic in water. The explanation I see everywhere is that you have to see the acid and base that makes up the salt, in the case of $\...
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1answer
57 views

How does sodium carbonate reduce pH?

Sodium carbonate is used in pools to raise pH. From my understanding, it would dissociate in water like so: $$\ce{Na2CO3 <=> 2 Na+ + CO3^2-}$$ To raise pH, doesn't it have to absorb hydrogen ...
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13 views

Why does the hydride ion in LAH act as a nucleophile rather than a base in the reduction of carbonyl compounds? [duplicate]

Why does the $\ce{H-}$ ion in $\ce{LiAlH4}$ act as a nucleophile rather than a base in the reduction of carbonyl compounds ?? Because $\ce{H-}$ being a small ion would act as a better base than a ...
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Is an acid a salt or not?

In our office, we discussed today what the exact definition of a salt is and whether an acid itself can be classified as a salt. Our first problem was that we couldn't get a definitive definition for ...
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0answers
26 views

The effect of lactose monohydrate on acid-base extraction of tolterodine tartrate

I am doing an organic chemistry project for school in the form of an acid-base extraction of tolterodine tartrate (Detrol) in ammonium hydroxide (or sodium hydroxide, haven't decided yet) and ...
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2answers
673 views

How to calculate the concentration of conjugate acid from given pH and pKa values?

Preface: Buffer solution (acid-base buffer). I am provided with a weak base, which I will designate B. $\mathrm{p}K_\mathrm{a}$ for $\ce{B}$'s conjugate acid, which I will designate $\ce{BH}$, is $8.1$...
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1answer
105 views

pH of very dilute acids

From doing some research on the site I have found that many people have posted about solutions of $\ce{HCl}$ where $[\ce{HCl}] = \pu{1e-8 mol dm-3}$ Here they are able to deduce $$[\ce{H+}] = \frac{[...
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1answer
102 views

Is omega 3 a specific fatty acid?

Is eicosapentaenoic acid (EPA) omega 3 or that's just a acid that comes with a omega 3? Same question for docosahexaenoic acid (DHA). Just want to know are both of those two acid omega 3 despite ...
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1answer
44 views

Acid solution — lower pH when diluted

Today I came across a "thought experiment" regarding $\mathrm{pH}$ of a diluted acid solution. This idea looks somewhat logical but obviously contradicts the reality. Can you show me where is the ...
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46 views

What is the pH of a solution of iron acetate?

What is the pH of a $\ce{0.1 M}$ solution of $\ce{Fe(CH_3COO)_3}$? I'm not sure how to do this, as it would involve complicated mass balance equations, but I think I can apply the approximation $\ce{...
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17 views

Does double ended fatty acid exist? [duplicate]

A fatty acid consists of a carbon chain, with a carboxylic acid on one end, and just a hydrogen on the other. Does a substance with two carboxylic acid ends and no hydrogen end exist?
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1answer
392 views

Writing Mass Balance Equations

I was curious if there is a specific reason why when writing mass balance reactions we always leave a $\ce{H+}$ on the left side of the equation as the professor did not explain so, or is it just ...
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1answer
38 views

What does pH of NH3 solution refers to?

I was introduced with an exercise which asks to find $K_\mathrm{b}$ of $\ce{NH3}$ when the $\mathrm{pH}$ of $\ce{NH3}$ solution with concentration $M_1$. Well, in order to solve it, I used the fact ...
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2answers
144 views

How pure gold is obtained back from dissolved state in Aqua regia?

I know Aqua regia is used for purifying gold by dissolving gold in it, but how that dissolved gold is obtained back in the pure state? I searched everywhere, but I didn't get the answer. So, I am ...
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1answer
65 views

Basicity of anions

Which one of the following is strongest base? A. $\ce{Cl-}$ B. $\ce{Br-}$ C. $\ce{I-}$ D. $\ce{CH3COO-}$ Someone please tell me the answer with proper reason. First I thought that it's $\...
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Are acid-base reactions always mediated by hydronium- and hydroxy-ions in aqueous solution?

If an acid and a base are disolved in water the reaction can be written as: H2SO4 + NH3 -> HSO4- + NH4+ On the other hand we can also consider: H2SO4 + H2O -> HSO4- + H3O+ and: NH3 + H2O -> NH4+ ...
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Chilling water in copper vessel

Does chilling drinking water in copper bottle result in any chemical reaction that turns it dangerous for consumption in any way? Few days back, in summer, I carried kokum juice in copper bottle. I ...
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1answer
44 views

Reverse washing soda buildup on stainless steel

In a home brewing project, I use washing soda (Na2CO3) to remove labels and glue from previously used bottles. In doing this, my flip-top bottles (which have a stainless steel flip top arm) often get ...
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3answers
67 views

Doubt on process to calculate pKa [closed]

I have to solve an exercise that I've been trying for a long time without success. Information that I have: pH @ certain temperature of an aqueous dissolution of an acid molar concentration ...
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3answers
7k views

How can the equilibrium shift, while Kc remains constant?

Consider the following reversible reaction. $$\ce{Cr2O7^2-(aq) + H2O(l) <=> 2 CrO4^2-(aq) + 2 H+(aq)}$$ What will happen to the position of equilibrium and the value of $K_c$ when more ...
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2answers
86 views

Density and concentration of hydroiodic acid [closed]

I weighted my hydroiodic acid sample: 25 ml weight 34.1 g, so the density is about 1.364 g/ml. I want to know its concentration based on density. Does anyone have the corresponding density chart?
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2k views

Calculating the pH upon titrating barium hydroxide and hydrochloric acid

Question: Calculate the pH produced from mixing $\pu{25.0 mL}$ of $\pu{0.420 M} $ $\ce{Ba(OH)_2}$ with $\pu{125 mL}$ of $\pu{0.120 M}$ $\ce{ HCl}$. Attempt: I'm learning about acids and bases ...
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1answer
34 views

What chemical can be used for getting rid of hard water spots on cars?

Most water spot removers available on Amazon or automotive stores are just fine abrasives which remove a small amount of your car's clearcoat every time you use them. I'm looking for a chemical which ...
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0answers
23 views

Equivalents Triethylamine in Swern-oxidation

Hey folks, so I've been wondering why the use of 5 equivalents of Et3N in this case of a Swern-oxidation is necessary. I have done this reaction succesfully quite a few times now, but all the ...
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36 views

Using concentrated sulfuric or nitric acid during titration of permanganate with oxalic acid

During titration of $\ce{KMnO4}$ with $\ce{H2C2O4}$, can we use concentrated $\ce{H2SO4}$ or $\ce{HNO3}$ instead of bench sulfuric acid?
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2answers
8k views

Mixing hydrochloric acid and sulphuric acid, both concentrated

In the chemistry lab, I stupidly decided to mix hydrochloric acid and sulphuric acid, both concentrated, in a random ratio, which was about $\pu{50 ml}$. When I poured them in one test tube, the ...
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2answers
16k views

Dissociation of HCl in aqueous solution

My question is regarding $\ce{HCl}$. In my book it states that: $$\ce{HCl (aq) -> H+ (aq) + Cl- (aq)}$$ I understand that when added to water the $\ce{H}$ leaves its electron to the $\ce{Cl}$ ...
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22 views

How do you purify phosphoric acid from cheap commercial (hardware-store) products?

I am looking for idea's on how to purify phosphoric acid for lab use, as the the price for reagent grade V's home-use ended with me buying a product designed as a rust-killer for steel... The ...
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1answer
55 views

Acid etching of float glass

While we have done some etching of glass with hydrofluoric acid alone, to achieve a matte white finish on float glass, I am curious to know what formula and procedure is required to create a more ...
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101 views

Is there a reliable chemical theory that predicts pKa based on structure?

Obviously, there are general stability arguments that can be made to estimate relative pKas, such as evaluating the stability of the conjugate base of an acid, or thinking about how polarized the bond ...
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113 views

Will silicon dioxide react with hydrochloric acid?

I have the following equation, based on the reaction of $\ce{SiO2}$ with $\ce{HF}:$ $$\ce{SiO2 + HCl -> SiCl4 + 2 H2O}$$ I want to know if this reaction is indeed feasible, what conditions may be ...
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1answer
66 views

Titration of barium(II) hydroxide by hydrochloric acid

$\pu{25 ml}$ of $\pu{0.024 M}$ $\ce{HCl}$ is titrated into a volumetric flask which initially contains $\pu{45 ml}$ of $\pu{0.034 M}$ $\ce{Ba(OH)2}$. Calculate the $\mathrm{pH}$. This is how I ...
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1answer
55 views

Why is the pH level of carbonation loss decreasing then increases afterwards?

We have done an experiment of the titration of unsealed sprite soda to find the amount of carbonic acid being loss on various duration (0 to 1 hour), due to decrease pressure. The calculation was to ...
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1answer
69 views

How do I write a procedure for creating a buffer?

I need to write an original procedure with exact numbers for creating a buffer: Create a buffer using $\ce{CH3COOH}$ and $\ce{CH3COONa}$ that has a $\pu{pH}$ of exactly $3.75$. A $\pu{50 mL}$ ...
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21 views

Why might litmus paper and universal indicator give conflicting pH readings in an acid-carbonate reaction?

The resulting neutralised (which wasn't actually neutralised due to not realising CaCO3's insolubility) solution between Hydrochloric Acid and Calcium Carbonate, as per balanced equation CaCO₃ + 2HCl ...
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1answer
30 views

Acid/Base Indicator [closed]

I'm not sure how the concept and math work on this problem. Can someone show me how you can get the answer, both conceptually and using math?
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1answer
214 views

How to create a buffer using CH3COOH and CH3COONa that has a pH of exactly 3.75?

I need to create a buffer using $\ce{CH3COOH}$ and $\ce{CH3COONa}$ that has a pH of exactly $3.75$. A $\pu{50 mL}$ sample of your buffered solution will have to be able to withstand the addition ...
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1answer
26 views

Calculating the pH of Strong Acid Solutions [closed]

Calculate the $\mathrm{pH}$ of a $\pu{1.5e–11 M}$ solution of $\ce{HCl}.$ How is the $\mathrm{pH}~7?$
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1answer
36 views

Difference of Ascorbic acid dissolved or precipitated in Glycerol?

Difference of Ascorbic acid (AA) dissolved or precipitated in Glycerol? Referring to pat US20110008445A1 Solution 1 At 25C, AA was dissolved in glycerol and alcohol (subsequently removed by ...
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1answer
62 views

Is barium sulfate soluble in dilute mineral acid?

I have read that $\ce{BaSO4}$ is soluble in $\ce{HCl}$ , but I am not sure whether this works for dilute acid as well. The reaction is - $\ce{BaSO4 + 2 HCl ->BaCl2 + H2SO4}$
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2answers
4k views

What is purpose of sulfuric acid in iodine extraction?

I am trying to extract iodine from kelp following this guide here. It calls for sulfuric acid, but I don't see what this does do help the reaction. I thought the reaction was simply oxidizing iodide ...
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30 views

How to make an aluminumoxide coating on an electrode?

The Questions is above. I am not a chemist but that is what I know: Aluminum has an Oxide Layer normally Aluminum-Oxide Layer can be broken down with NaOH Zink coatings are done by galvanic coating ...