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).
2,570
questions
2
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1answer
29 views
Acidity of thiamine - how comes hydroxide anion with pK about 15 ionizes thiamine with pK about 18?
Textbooks say removing proton from thiamine's C atom will produce a resonance stabilized carbanion which is hence bioactive. That's OK, but how comes that 1) we abstract the acidic proton with the OH ...
0
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0answers
22 views
What is an alternate way of preparing a sodium hydrogen phosphate/sodium dihydrogen phosphate buffer through titrating an acid with a strong base?
So my friend and I are stumped. This is in the context of achieving the sodium hydrogen phosphate/sodium
dihydrogen phosphate buffer by titrating the acid with a strong base.
My friend says the answer ...
1
vote
1answer
38 views
Why don't dicarboxylic acids show hydrogen bonding in spite of the fact that carboxylic acids exist usually as dimers in polar aprotic solvent?
I have seen several examples:
The fact that maleic acid is more soluble in water than fumaric acid in spite of the fact that it must be able to show intramolecular hydrogen bonding.
trans-...
1
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0answers
52 views
Adding a base and a salt to a hydrated complex
The question goes like this:
$\ce{Fe(NO3)3}$ V= $\pu{1 liter}$ and $\ce{[Fe(NO3)3]} =\pu{0.1 moles/liter}$.
Calculate the $\mathrm{pH}$ of this solution using the values of $K$ given.
We add a solid ...
1
vote
1answer
69 views
Why do bases taste bitter?
My chemistry teacher told us that acids taste sour and bases taste bitter. After reading Do acids without hydrogen taste sour? and https://en.wikipedia.org/wiki/Taste#Sourness I learned that sourness ...
-1
votes
0answers
27 views
What is the principal reaction
I was reading this chapter about ionic equilibrium in my textbook when I stumbled upon this:
Knowing the ionisation constant, $K_\mathrm a$, of an acid and its initial concentration, c, it is ...
-1
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0answers
12 views
Please, help me to calculate the exact amount of TEA to neutralize Cocoyl Glutamic acid [closed]
I need to neutralize Cocoyl Glutamic Acid with TEA. Could you please, show me the equation or help me calculate the amount of both compounds. Thank you in advance.
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0answers
18 views
Alkaline hydrolysis of imines
In "advanced organic chemistry part (A)" pg:469, the author states that the rate-determining step in alkaline hydrolysis of imines is the hydroxide addition to imines and when pH decreases ...
2
votes
3answers
88 views
White snow-like powder below sodium hydroxide solution [closed]
I have created sodium hydroxide solution with half cell brine electrolysis but, finally I got white snow-like insoluble powder sank below sodium hydroxide.
What should I do keep or remove it?
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0answers
31 views
Lewis Bases are also Bronsted bases
Is there anything wrong with the statement - 'All Lewis Bases are also Bronsted Bases'?
According to me this statement is right as Lewis Bases can donate their lone pair to H+ ion but in the answer, ...
0
votes
2answers
59 views
Reaction of copper with nitric acid [closed]
$\ce{Cu}$ reacts with $\ce{HNO3}$ though $\ce{Cu}$ cannot replace $\ce{H}$ due to its less reactivity. Then, why does it react with $\ce{HNO3}$?
0
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0answers
24 views
Acid and Salt Reaction [closed]
What is the name given to the reaction between an acid and salt? For example, the reaction between hydrochloric acid and calcium carbonate salt, is there a specific name for these type of reactions.
1
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2answers
37 views
Aspartic acid conjugate base acidity
Question
Which hydrogen among the four in the conjugate base of aspartic acid is most acidic?
Answer
My attempt
I am confused between Hb and Hc
I know Hd has $\mathrm pK_\mathrm a \approx 9$, so ...
-4
votes
0answers
12 views
HCL concentration conversion [closed]
I am following a YouTube channel "Applied Science" for a project, at one point in the video he asks to add 15ml of HCL in 250ml of water, but he does not specify the concentration of HCL, ...
-1
votes
2answers
61 views
How to find the stoichiometric amount of nitric acid reacting with tin?
To find the amount of $\ce{HNO3}$ behaving like an acid in the reaction
$$\ce{Sn + HNO3 -> Sn(NO3)2 + NH4NO3 + H2O},$$
I first balanced the reaction using oxidation number method which gave me
$$\...
0
votes
1answer
61 views
Why sugar solution/sugarcane juice becomes sour when kept for certain time?
I stir-dissolve some sugar in a cup of water and then keep it open for certain time (say a few hours), when I taste it I feel that it has became sour.
I have observed the same thing many times when I ...
0
votes
1answer
38 views
Comparison of basicity of o-phenanthroline and ammonia
I was trying to compare the basicity of o-phenanthroline and ammonia.
According to me, the factors that are seen in o-phenanthroline are:
o-Phenanthroline has two nitrogen atoms at the 1,10 positions....
1
vote
0answers
21 views
Can the inner amine groups of Bacteriopheophorbide A become positively charged in aqueous solutions without the use of very strong acids?
In an attempt to calculate the pKa of the carboxylic acid group of Bacteriopheophorbide A (BPheo, Pubchem), I generated the structure in MarvinSketch (ChemAxon product) and I came across an ...
2
votes
0answers
29 views
How to calculate the pH of solutions of amphoteric salts? [duplicate]
I've been trying to understand how to calculate the pH of solutions of amphoteric salts, but I just can't figure it out. So, I've seen that it is commonly explained like this (example for a solution ...
0
votes
0answers
14 views
Acidity of cyclopentadiene [duplicate]
Why is cyclopentadiene more acidic than dibenzocyclopentadiene although in the latter, the negative charge will be more distributed and consumed in resonance stabilization.?
0
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0answers
54 views
Effect of adding an acid or base to water with respect to concentration of ions
So I know that there's auto-ionization of water according to:
$$\ce{2H2O <=> H3O+ +OH-} \tag{1}$$
If I have pure water where the concentrations of both $\ce{H3O+}$ and $\ce{OH-}$ is $10^{-7}$
...
1
vote
1answer
64 views
Does rate of auto-ionization of water change after adding a strong acid?
We know that a reaction could have different rates at equilibrium. For example, lets take the reaction:
$$\ce{A + B -> C }$$
At equilibrium, the rates of formation and dissociation will be equal:
$$...
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votes
1answer
30 views
Potassium tetraoxalate preparation [closed]
How is potassium tetraoxalate produced industrially? In fact How I can limit the reaction of $\ce{H2C2O4}$ and $\ce{KOH}$?
Or is there any other route for this purpose?
8
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2answers
487 views
Why is 4-hydroxypyridine more acidic than benzoic acid?
4-hydroxypyridine (or 4-pyridone) has a $\mathrm{p}K_\mathrm{a}$ in the ballpark of $3$ to $3.33\:^1$ (in the pdf linked below, the $\mathrm{p}K_\mathrm{a}$ of 1-methyl-4-pyridone has been given to be ...
0
votes
2answers
73 views
Calculation of pH in acid base reaction
This problem(from ionic equiibrium) states:
We are given $\pu{40 mL}$ of $\pu{0.1 M}$ $\ce{HCl}$ and $\pu{10 mL}$ of $\pu{0.45 M}$ $\ce{NaOH}$ in two separate beakers. These two solutions are mixed. ...
0
votes
1answer
73 views
Reaction of Silicon Dioxide with Hydrofluoric Acid [duplicate]
I learnt that $\ce{SiO2}$(Silicon dioxide) doesn't react with any acid except $\ce{HF}$. So what is special about $\ce{HF}$?
Why does only $\ce{HF}$ reacts with $\ce{SiO2}$ even though $\ce{HF}$ has a ...
-1
votes
0answers
20 views
How to determine the pH of a given aqueous solution of HCl of unknown concentration using double titration? [duplicate]
I currently have a practical to do for school in which I have to to determine the pH of a given aqueous solution of HCl of unknown concentration. My teacher mentioned something about double titration ...
7
votes
1answer
227 views
How can I properly calculate the isoelectric point (pI) of amino acids?
The following amino acid is called lysine. I was asked to calculate its isoelectric point, with the given $\mathrm pK_\mathrm a$ values.
I've searched a lot, and the most helpful post that I found ...
3
votes
1answer
56 views
Alkoxide metathesis
I am attempting a synthesis for acetylacetone. The preparation I wish to carry out is described on orgsynth by condensation of acetone and ethyl acetate with a base catalyst.
The problem for me is ...
5
votes
0answers
44 views
What acids, solvents is lithium-6 fluoride soluble in (other than HF)?
$\ce{LiF}$ is quite insoluble in water, and I'm trying to use some water-soluble acid or solvent to dissolve $\ce{^6LiF}$ (95% enriched) in. I'm not a chemistry person, I'm a radiation detection ...
0
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2answers
59 views
How to determine the product from my attempt of HOCl synthesis
This is a follow up to this question. Here is my short procedure:
start with 200mL distilled water
add 7mL of 8.25% sodium hypochlorite (.11M) to the solution. The resulting solution should be 3.7*10$...
1
vote
2answers
111 views
How can magnesium hydroxide be a strong base and be sparingly soluble at the same time?
A strong base means it completely dissociates forming $ OH^- $ ions when added to aqueous solution.
Sparingly soluble means it dissolves very little when added to aqueous solution.
Yet magnesium ...
4
votes
2answers
164 views
Defining general acidic strength
The $K_\mathrm{a}$ or $K_\mathrm{b}$ values provide an idea of how likely a specific step is to happen.
However, how do you specify one acid just being stronger than another, as in the case of $\ce{...
2
votes
4answers
350 views
Help with determining concentration of magnesium hydroxide for a specific pH level
This seems like such an obvious and elementary-level question for someone who has taken high school chemistry, but yet I'm having a difficult time solving it. I need to find the right amount of $\ce{...
1
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0answers
40 views
Why doesn't but-2-yne show acidic character?
I found this in several sources and also found this while solving a few questions that but-2-yne does not show acidic character (or atleast not a significant amount of acidity) compared to terminal ...
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votes
1answer
26 views
What’s the difference between? [closed]
In my exam paper, I got this question:
Give the name of the fourth member of the homologous series of carboxylic acids.
My answer was butanoic acid, but the answer was butyric acid. What’s the ...
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1answer
32 views
An equilibrium question involving mixing equal volumes of HCl and H2SO4
Question: Calculate the concentrations of H3O(+) and SO4(2-) in a solution prepared by mixing equal volumes of 0.2M HCl and 0.6M H2SO4. (Ka1 for H2SO4 is very large, and Ka2 for H2SO4 is 1.2E-2)
Here ...
-1
votes
2answers
86 views
Which make HCO3- to show two pH values at two scenarios?
According to the below two titrations,
Image Reference: https://chem.libretexts.org/Bookshelves/General_Chemistry/Book%3A_Chem1_(Lower)/13%3A_Acid-Base_Equilibria/13.05%3A_Acid%2F%2FBase_Titration
If ...
0
votes
2answers
87 views
Battery acid solution preparation from 98% ACS Sulfuric Acid
I'm trying to prepare some battery acid for activating a flooded lead acid battery I had purchased. The battery concentration should be around 36-28% sulfuric acid solution. I have decided to go with ...
0
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0answers
25 views
Acid catalyst choice on reaction of carbonyl group and O/N nucleophiles
For oxygen nucleophiles, e.g. $\ce{ROH}$, when reacting with a carbonyl group to form acetal, the acid catalyst used is protonated alcohol.
for nitrogen nucleophiles, e.g. $\ce{RNH2/RR'NH}$, when ...
1
vote
1answer
68 views
NGP in Finkelstein reaction
The question is to find the product in the following reaction-
In the answer given, they have replaced Cl with I and inverted the configuration at that carbon(Finkelstein reaction).
But $\text{I}^-$ ...
7
votes
3answers
2k views
Why are acetic acid and sodium bicarbonate mixed to unblock a drain?
I have always wondered about the rationale behind combining white vinegar and sodium bicarbonate to perform household cleaning jobs, and to unblock drains. I would have expected white vinegar to act ...
0
votes
1answer
153 views
Reaction of cinnamic acid with Br2/Na2CO3
The first reaction produces benzaldehyde, and the next one (perkin's condensation)produces Cinnamic acid.(X)
Now the treatment of X with $\ce{Br2/Na2CO3}$ is whats troubling me. $\ce{Na2CO3}$ being a ...
-1
votes
1answer
40 views
Calculating dissociation constant at different pKw values
What are the standard approaches to calculating how dissociation constants for acids and bases, $\mathrm{p}K_\mathrm{a}$ and $\mathrm{p}K_\mathrm{b}$, change as the ionic product of water, $\mathrm{p}...
-3
votes
1answer
58 views
Reaction Of Carbonic Acid With NaCl [duplicate]
I was just wondering if it was possible for anyone to specify what reaction conditions are required for the reaction between $\ce{H2CO3}$ (Carbonic Acid) and $\ce{NaCl}$ (Sodium chloride)?
Does this ...
-1
votes
2answers
56 views
Stability of F- Cl- Br- I-? In aqueous state [closed]
If we talk about hydrolysis F- will be more heavily hydrolysed so it should be more stable in aqueous state.
But I know that HI is a stronger acid than HF. So the stability of conjugate acid ie I- ...
1
vote
2answers
93 views
Help understanding the synthesis of HOCl
My goal is to add acetic acid to sodium hypochlorite to reach a ph of between 3.8-5.5 and produce hypochlorous acid. I’ll be using bromocresol green as a ph indicator. I was reading about how to ...
1
vote
0answers
89 views
What the product of this reaction?
The reaction is as follows, with (i) being my answer, and (ii) being the correct answer in the book.
My question is why is the product (ii) formed here and elimination not favoured here? I think that ...
0
votes
1answer
84 views
Can NaOH and NaH2PO2 exist together in aqueous solution?
Can $\ce{NaOH}$ and $\ce{NaH2PO2}$ exist together in aqueous solution?
My textbook denies it, but I feel that since $\ce{NaH2PO2}$ is acidic, it should react with $\ce{NaOH}$, because in my textbook ...
-1
votes
2answers
50 views
Why we do not add salt water to the batteries instead of acid? [closed]
Actually I was just thinking that since we add acid to the batteries to increase the conductivity but the thought simply crossed my mind that salt are strong electrolytes so there should be a good ...
