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 is on the other hand a chemical species/ molecular entity having an available ...

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0answers
32 views

Is the pH of a solution (orange juice) affected by the presence of a metal?

Is the pH of a solution (orange juice) affected by the presence of a metal (aluminium, tin or iron for example)? I know that the metal will corrode in the presence of an acid (citric acid in this ...
0
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0answers
23 views

Doubt in the structure of acids [closed]

Why do acids form $\ce{O-H}$ bonds although it requires just H molecules? And O-H bonds require huge amount of energy, so why do they form so?
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0answers
23 views

Calculating the pH of acetic acid/acetate buffer solutions [closed]

An acetic acid-solution acetate buffer of pH 5.00 has 0.100 M NaOAc. Calculate the pH after the addition of 10 ml of 0.10 M NaOH to 100 ml of buffer.
4
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1answer
49 views

Atmospheric Nitrogen gas and human body pH buffers

It looks like the human body doesn't have the ability to breakdown atmospheric $\ce{N2}$, as of now $\ldots$ So an enzyme like nitrogenase (found in cyanobacteria) fixes $\ce{N2}$ and produces ...
6
votes
1answer
40 views

Does phosphoric acid remove stainless steel electropolished layer?

Electropolished stainless steel has a high corrosion resistance due to the oxide film that is created during electropolishing. The film mainly consist of chromium(III) oxide. Phosphoric acid is ...
1
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2answers
53 views

What is the quickest way to dissolve steel?

What is the quickest way to dissolve a large chunk of steel? I mean a very quick reaction, assuming that the interaction occurs in a sealed or semi-sealed environment? Reaction times of the order of a ...
1
vote
1answer
76 views

Are my protolysis equations right?

We had the task to solve several salts in water and measure the pH value of the solution. After that we should "create" the protolysis equation and to tell about Chemical equilibrium[s]. I get some ...
5
votes
0answers
46 views

A doubt on phase equilibrium?

Below is a transcript of this doubtful question: A weak monobasic organic acid HA issoluble in both solvents, water and $\ce{CHCl3}$. 500.0 cm$^{3}$ of a solution of $\ce{HA}$ is 0.057 mol ...
6
votes
1answer
49 views

Condition For NaHCO3 to react to form CO2 with organic acids

My professor told us the following: $\ce{NaHCO3}$ will react to evolve $\ce{CO2}$ whenever the acidic nature of the reactant exceeds the acidic nature of benzoic acid. I want to know why ...
5
votes
2answers
147 views

Why is H2S2O7 stronger than H2SO4?

I think sulphuric acid will be the correct answer. I can't find answer. Please show your reasons. My attempt: I've read that, for an oxi-acid, the oxidising number of the central atom shows the ...
4
votes
1answer
35 views

Calculating pH in titration of monoprotic weak acid with strong base

I’m working on this problem: $25.0\:\mathrm{ml}$ of $0.10\:\mathrm{M}$ $\ce{CH3COOH}$ is titrated with $0.10\:\mathrm{M}$ $\ce{NaOH}$. What is the $\mathrm{pH}$ after the addition of ...
2
votes
1answer
115 views

Phosphate buffer from phosphoric acid and K2HPO4?

Is it possible to make a solution of ph 7 phosphate buffer solution using phosphoric acid and $\ce{K2HPO4}$ ? How can I calculate the amount of $\ce{K2HPO4}$ needed for 1L of phosphoric acid ? Edit: ...
5
votes
3answers
206 views

Why amino acids (Zwitterion) become either negative or positive at low and high pH solutions?

The amino acids are Zwitterions. In neutral pH, an Amino acids' amino group has a + postive charge and Carboxyl group has - negative charge. They cancel each others charge thanks to the H that's ...
3
votes
1answer
53 views

Do carboxyl groups behave like a base and amino groups behave like an acid when creating peptide bonds?

Peptide bonds are synthesized when the carboxyl group of one aminoacid molecule reacts with the amino group of the other aminoacid molecule, causing the release of a molecule of water. Water ...
8
votes
1answer
159 views

How to analyze a acid and salt mixture using titrimetry?

Given a mixture of $\ce{HCl}$ and $\ce{MCl3}$ and the following dissociation constants for $\ce{M(OH)3}$, how can the concentrations of $\ce{HCl}$ and $\ce{MCl3}$ be determined separately by titrating ...
4
votes
1answer
57 views

Pourbaix diagram – writing reactions

How would you go about writing the reaction between water and chromium metal under standard acid and base conditions? I know you would have to look at the vertical lines at pH 0 and 14 but I don’t ...
2
votes
0answers
29 views

Is passivation of stainless steel feasible in the field?

Does anyone have input or experience on passivation of stainless steel, particularly in outdoor environments where submersion of components is not practical due to location or size? Nitric acid (and ...
4
votes
0answers
110 views

How to calculate the pH of a 0.325 M solution of C5H5NHF?

How to calculate the $\mathrm{pH}$ of a $0.325~\mathrm{M}$ solution of $\ce{C5H5NHF}$? The $K_\mathrm{b}$ for $\ce{C5H5N}$ and $\ce{C5H5NH+}$ is $1.7\cdot10^{-9}$. Here's my work, but it's wrong (at ...
2
votes
2answers
44 views

What is the difference between these equations for the Contact process?

Some webpages describe the contact process as this (I left out $\ce{SO2}$, $\ce{SO3}$ production): $\ce{SO3 + H2SO4 -> H2S2O7}$ After this, it is controllable to add water to the oleum therefore ...
0
votes
0answers
22 views

Qualitative Analysis of Anions

From the image above, if you all could take a loot at step 1a. It makes no sense to me. I do not understand why adding $\ce{CH3COOH}$ has any effect on the solution whatsoever. What is the point of ...
5
votes
3answers
71 views

Is the Henderson–Hasselbalch equation volume independent?

Looking at this equation $\mathrm{pH} = \mathrm{p}K_\text{a} +\log\frac{[\ce{CB}]}{[\ce{A}]}$ makes me think that it is concentration independent. What I mean is, when we look at ...
4
votes
1answer
62 views

What's the simplest way to etch Nickel and Chromium sputtered layers?

I have to etch a very thin film (50 nm) of Nickel ($\ce{Ni}$) on a 100 nm $\ce{SiO2}$/$\ce{Si}$ substrate. Additionally, there is a ~5 nm adhesion layer of $\ce{Cr}$ under the $\ce{Ni}$ that I'd also ...
5
votes
1answer
46 views

steam distillation of 4-bromoaniline , why render it basic prior

In the multistage synthesis of 4-bromobenzenamine, why must the solution be rendered alkaline prior to the steam distillation after the hydrolysis of 4-bromo-N-ethanoylbenzenamine?
3
votes
1answer
55 views

E2 reaction - strong base

In E2 reaction, there is more than one product. According to Zaitsev’s rule – “The alkene formed in greatest amount is the one that corresponds to removal of the hydrogen from the β-carbon having the ...
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votes
1answer
44 views

How to compare acidic strength of following organic compounds? [duplicate]

Why Acetic acid is weaker acid than benzoic acid?
5
votes
3answers
295 views

Calculating Buffer Capacity

I completed a titration of Ammonium Acetate buffer solution and to it I added 2M Hydrochloric Acid. I measured the initial pH of the buffer solution before any acid was added and I used methyl ...
4
votes
1answer
58 views

Water reacts or doesn't react?

I know that when you have $\ce{HCl}$, $\ce{H2O}$, and $\ce{NaOH}$ that you produce $\ce{H2O}$ and $\ce{NaCl}$. However some people say water does react and so would think that this 2 step reaction is ...
5
votes
2answers
87 views

Solvent effects on acidity of ethanoic acid

Is ethanoic acid most acidic in DMSO, water or methanol? I suspect that the conjugate base would be most stabilized by a polar protic solvent (meaning it's weakest in DMSO), however, water and ...
6
votes
2answers
73 views

Selecting between redox and neutralization reactions for a mixture of HCl, H2SO4 and NaOH

I know that you can have 2 acids reacting with 1 base. These 4 reactions are an example of this: $\ce{3 HCl + H2SO4 + NaOH -> 3 H2O + SCl2 + O2 + NaCl}$ $\ce{6 HCl + 4 H2SO4 + 2 NaOH -> 8 H2O ...
0
votes
1answer
24 views

Which effect does adding hydrogen chloride have when determining the concentration of sodium hypochlorite in bleach via titration have?

Many of you might be familiar with this and I do understand this completely, however I do have a question. If you are familiar with this, then this is the equation and this is the question for it. ...
2
votes
1answer
87 views

Thymol Blue - molar absorptivity

I did a lab about spectrophotometry and right now I need the molar absorptivity(ε) of thymol blue in acidic solution and also in basic solution. I have tried looking online but I haven't found the ...
5
votes
1answer
67 views

Determining (approximately) the amount of a strong base needed to change a buffer's pH by a certain number of units

I'm measuring buffer capacity by titrating $\ce{NaOH}$ into a buffer of $\ce {H3PO4 + NaH2PO4}$. I'm measuring buffer capacity by recording the amount of $\ce{NaOH}$ required to increase the ...
3
votes
1answer
61 views

Neutralisation and end point pH

So I just finished my final paper yesterday and I tried to attempt this 8 mark question. I am not sure how to do it. $25\,\mathrm{ml}$ of $0.5\,\%~\mathrm{w/v}$ lactic acid ($\ce{C3H6O3}$, ...
5
votes
1answer
83 views

Investigating a factor affecting buffer capacity

I'm preparing for an experiment to investigate some factor affecting buffer capacity. At the moment, I'm looking at using a $\ce{NH_3}$ ($2\,\mathrm{M}$) $+$ $\ce{NH_4Cl}$ buffer, but I'm not sure ...
1
vote
1answer
43 views

Does DMT-Acetate become Polar in H2O, with added NaCl?

I'm extracting DMT (N,N-dimethyltryptamine) from Acacia confusa via acid/base. I extracted the DMT with $\ce{H2O}$ and acetic acid, converting it to DMT-acetate. Here, I used a non polar solvent, ...
8
votes
2answers
118 views

What is the meaning of cmmol in chemistry?

I came across a unit called $\text{cmmol dm}^{-3}$ in buffer solutions. What does this unit mean?
5
votes
1answer
131 views

Is it possible to create a 4 inch by 4 inch channel through concrete using acid?

I'm trying to figure out a way to eat through concrete without damage pex tubing inside (its a radiant heated slab). Is there any way using some type of acid (hydrofluoric, muriatic ) to eat a 4 inch ...
5
votes
2answers
80 views

How can I choose an indicator for determining the concentration of a base using its pKb values?

I have a base $\ce{M(OH)_{3}}$ having 3 $\mathrm{p}K_{\mathrm{b}}$ values as, $$ \mathrm{p}K_{\mathrm{b}_{1}} = 0.5\\ \mathrm{p}K_{\mathrm{b}_{2}} = 3.7\\ \mathrm{p}K_{\mathrm{b}_{3}} = 7.7\\ $$ If a ...
0
votes
0answers
22 views

Is a negative pH value possible? [duplicate]

Is a negative pH value possible in room temperature...teachers don't tend to teach about the pH of acid or base solutions which are higher than 1M.
3
votes
0answers
184 views

The acidity of group 4 tetrahalides

I've been asked to compare the relative acidity of $\ce{CF4}$ and $\ce{SiF4}$. As both have noble gas structures neither can act as a lewis acid and so I assume the question is inferring that they ...
2
votes
1answer
47 views

Conjugate Acid/base pairs [closed]

Why are these not conjugate acid/base pairs? $\ce{CH3NH3+/CH2NH3}$ I know that the a conjugate base is formed from an acid giving away a proton. $\ce{CH3NH3+}$ is losing a $\ce{H+}$ and to become ...
2
votes
1answer
57 views

What is the necessary volume of concentrated HCl to prepare a solution with a pH of 1.8?

Here is my question: What volume of a concentrated $\ce{HCl}$ solution, which is $36.0\%$ $\ce{HCl}$ by mass and has a density of $1.179~\mathrm{g~mL^{-1}}$, should be used to make ...
2
votes
1answer
23 views

Will bleach combined with any of these chemicals create poisonous gas?

I need to know if a combination of bleach and the chemicals below will create poisonous gas. Will it create chloramine, and will there be any visible gas? 1) Sodium laureth sulfate 2) Sodium citrate ...
3
votes
1answer
158 views

Acidic Strength of Substituted Benzoic Acids

Comparing the acidic strength, the nitro-substituted group is definitely more acidic. This can be reasoned by fact that a higher delta positive charge which develops on the H due to the strong -M ...
3
votes
1answer
75 views

Basicity Alteration Due To Ortho Effect In Methoxy Aniline System

I wanted to ask something more in reference to this question Ortho-effect in substituted aromatic acids and bases Suppose instead of toluidine, 2-methoxy aniline and 3-methoxy aniline are ...
6
votes
1answer
86 views

Protonation of ketone and ester

If there is a ketone and ester functional group in one same compound and I want to protonate with $\ce{HCl}$, which one will protonate first? Is it the carbonyl group in the ketone or the carbonyl ...
7
votes
1answer
269 views

Why is picric acid more acidic than carbonic acid?

I just had a question in a test asking to compare the relative acidity of picric acid (TNP) and carbonic acid, $\ce{H2CO3}$ (not phenol). It turns out that TNP is more acidic. I have no idea why? Is ...
3
votes
1answer
25 views

Does a weak acid undergo it's weak ionization upon the addition of any kind of base?

For an example let's assume we have a weak acid HA . And we add either a strong or a weak base.Then what I want to know is whether the weak ionization of the acid HA taken place?. Weak ...
2
votes
1answer
43 views

Strong base, strong acid titration problem

Here is a problem: Titrate 1 M sulfuric acid with 50 ml of 1 M sodium hydroxide solution. What volume of sulfuric acid will be required for neutralization. This is a simple problem. My ...
0
votes
1answer
53 views

Why does pKa of a acid-base indicator equal to the pH when the equivalence point is reached?

To be honest, I just don't get it. I had this question while reading a Chemguide article, on this topic: I think my confusion is caused by the way I look at pKa of acid-base indicator. Should you ...