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).
3,223
questions
-2
votes
0
answers
7
views
How should i do Stoichiometry partaking mass and volume : for an experimental reaction?
I am making some fuming nitric acid employing a rudimentary reaction between KNO3 and conc.H2SO4 .I planned to use 23.27 g of KNO3 and the reckoned amount for conc.H2SO4(98%) is 22.57g .So my question ...
0
votes
1
answer
39
views
Why does hydrohalogenation usually proceed through protonation and not a pseudopericyclic reaction
Why does HX not add to alkenes via a pseudopericyclic reaction involving the alkene pi bond, a halogen lone pair, and the sigma bond of the hydrohalic acid?
- 119
-1
votes
1
answer
83
views
Why did hydrochloric acid cause copper to gain weight after soaking in it overnight?
I recently did an experiment involving 2M hydrochloric acid and two different metals, iron and copper. This experiment was to investigate how the metals reacted to the acid by letting them sit in the ...
- 11
1
vote
0
answers
57
views
Why does the acidity order (CH₄ < NH₃ < H₂O < HF) follow the bond strength order (C-H < N-H < O-H < F-H) when stronger bonds should resist breaking? [duplicate]
I'm trying to understand the relationship between bond strength and acidity in the series CH₄, NH₃, H₂O, and HF. The bond strength order is C-H < N-H < O-H < F-H, meaning the F-H bond is the ...
- 41
-2
votes
2
answers
83
views
about acid-base equlibrium
I have one good question guys for chemistry community
Let me explain the question and i want satisfactory and simple tangible answer
Q: In Our chemistry lesson i.e "Acid-Base equilibria" we ...
- 9
-1
votes
1
answer
42
views
Can lead hydroxide react with potassium nitrate?
There's a chemical reaction where $\ce{Pb(NO3)2}$ reacts with $\ce{KOH}$ to form $\ce{KNO3}$ and $\ce{Pb(OH)2}$ (chalky white ppt).
But I have a doubt if the opposite reaction is possible too, i.e. $\...
- 15
-1
votes
1
answer
46
views
How to separate acid and base streams in water electrolysis [closed]
I am very new to chemistry and am trying to figure out how to separate the acid-base streams in standard water electrolysis. Namely, I want to end up with two streams, one of OH-1 ions and one of H+ ...
0
votes
1
answer
43
views
Magnesium Bicarbonate Synthesis, How to be Certain of the Moles of CO2 added to Water?
Background Research
Through googling all I find is using chilled sparkling water or carbonating water and then adding a teaspoon of magnesium hydroxide to it.
The problem with these methods is that ...
- 133
1
vote
1
answer
67
views
Study of model reaction HCl + NH3 in water
I'm a student, and I've been given the neutralization reaction between $HCl$ and $NH_3$ to study. It Is asked to calculate how much acid is necessary to add to a $NH_3$ solution to make all the ...
- 153
0
votes
1
answer
76
views
Redox mass balancing trouble
I'm a university student. I've been given the following redox to study and balance using ionic-electronic method:
$$CuS_{(aq)} + HNO_{3(aq)} \longrightarrow Cu(NO_3)_{2(aq)} + H_2O_{(l)} + SO_{2(g)} + ...
- 153
0
votes
1
answer
49
views
What pH will a pH 13 sodium hydroxide solution drop to exposed to air, and how fast?
Let’s say I dropped a bottle of lye heavy, liquid soap with a pH of 13.
If this soap lies around exposed to air, what pH will it drop to once the sodium hydroxide has turned into sodium carbonate? And ...
- 11
0
votes
1
answer
53
views
Acidity of toluene compared to propyne
Why is propyne more acidic than toluene? The carbanion formed in case of toluene is easily stabilised by resonance and -I effect of toluene. In case of propyne there is an electron donating ...
0
votes
0
answers
32
views
How will acetic acid behave in specific solution?
For my experiment I have a 1:1 solution of 1.5 (w/v) chitosan and sodium-alginate (SA) in deionized water separately. Beforehand, I had to dissolve the chitosan-powder in 1% acetic acid solution.
I ...
- 53
5
votes
2
answers
307
views
Help troubleshooting inconsistent pH measurements
We're a small homestead cheese manufacturing company. Recently we've done R&D for cheese that's salted by means of a brine.
Problem: we have had inconsistent pH readings and we are left confused ...
- 443
1
vote
1
answer
80
views
The pKa of 3,4-dihydroxycyclobutane-1,2-dione (not squaric acid)
Would like to know if 3,4-dihydroxycyclobutane-1,2-dione reacts with NaHCO3 to give effervescence?
2
votes
2
answers
61
views
Why is a borax solution basic?
When searching the wikipedia link for borax, it tells you that dissolving borax in water gives a basic solution.
On further inspection, one site lists the reaction equation (https://www.vedantu.com/...
- 453
-4
votes
1
answer
32
views
PREPARATION OF SALTS [closed]
A liquid turns white anhydrous copper sulfate blue and has a boiling point of 103°C.
Which could be the identity of the liquid?
A alcohol
B petrol
C salt solution
D pure water
-2
votes
1
answer
50
views
Only the Hydrogen ions bonded to oxygen are replaceable in Phosphorous acid. Why?
The basicity of Phosphorous acid is 2 though it has 3 Hydrogen ions. I heard that it is because only the hydrogen ions bonded to Oxygen (Only 2 H ions) are replaceable. Why is it so?
- 11
1
vote
1
answer
44
views
H+ concentration of the mixture of a strong and weak acid
I reviewed the complete solution (hand-written) to the problem at Calculation of the pH of a mixture of a strong acid and weak acid.
My question is why it is okay to apply the K1 value for the weak ...
- 11
-1
votes
2
answers
103
views
How can adding a strong base to a weak base be the same as a strong base in solution problem?
In professor's lecture on acid-base titration, professor says (at this point of the video, link should start about the time she says it)
"adding a strong base to a weak base should be treated as ...
- 255
2
votes
0
answers
53
views
Stability of carbenes
For predicting the order of formation of carbenes from the following compounds (CHI3, CHBr3, CHF3), we can take a look at the stability of the halide anion that is formed (I- vs. Br- vs. F-) and the ...
- 31
2
votes
2
answers
137
views
Why would the theoretical pH not match the measured pH when performing a titration of NH4OH with HCl?
I ran a weak base - strong acid titration experiment using an automatic titrator. I started with an aqueous ammonia stock solution (somewhere in the range of 0.1 - 2.5 wt.%) that was left open to ...
- 39
2
votes
0
answers
29
views
Irreversible uncharged acid/base indicator
I am conducting a process in an electrochemical cell where at the cathode or anode surface the pH might be acidic or basic. To figure out if either one is correct I would like to find a reaction that ...
- 399
-4
votes
1
answer
36
views
Alkaline + Sweat + heat = cat piss? [closed]
Back in the 70s my Army unit spent three days in the Arizona desert, temperatures reached over 110°, we only told to only bring one set of camouflage fatigue. After the maneuvers we were bussed to the ...
-5
votes
1
answer
61
views
Why should the pH change when I add sodium hydroxide to water? [closed]
I am a student and I am trying to understand the concept of pH.
If I add pure $\ce{NaOH}$ in water, it leads to the formation of $\ce{OH-}$ ions in the water. But this shouldn't lead to any change in ...
3
votes
0
answers
27
views
Non-binding buffer at pKa of roughly 6 that dissolves in ethanol?
I'm trying to find a proper buffer for my experiment, which I'd appreciate some suggestions on. I have a solution in which I want to measure the concentration of magnesium ions using a fluorescent ...
- 31
0
votes
0
answers
33
views
Why is a basic (not acidic) electrolyte frequently suggested for electrolytic de-rusting of metal or iron objects?
For home or do-it-yourself electrolytic de-rusting of steel or iron objects, the use of a soda-based electrolyte, such as "washing soda" (sodium carbonate) is almost always mentioned.
I have ...
10
votes
2
answers
2k
views
What is "soda asbestos"?
I found an old bottle labeled "soda asbestos" in the lab. It is a granular material with a grain size of about 0.5 mm. A newer label put on top says "sodium hydroxide".
It is brown,...
- 5,462
-4
votes
2
answers
43
views
Which one of these is neither acidic or amphoteric? Would the same question be "which one is the most basic?" ? It says that b) is the answer [closed]
I'm stuck on this problem that isn't explained much in the teachers notes (no detailed explanation on why Bi2O3 is the answer).
Google gives mixed answers (it's either basic or amphoteric), and ...
4
votes
2
answers
483
views
Calculating the heat of reaction between sulfuric acid and sodium hydroxide
For my lab report I have to calculate the theoretical heat of reaction $\Delta H_{\text{rxn}}$ between sulfuric acid $\ce{H2SO4}$ and sodium hydroxide $\ce{NaOH}$ using their heat of formations. The ...
- 59
0
votes
0
answers
75
views
How to predict whether a redox or an acid-base reaction will occur? [duplicate]
I've been thinking a lot about this question, but even after intense research, I didn't find any satisfying answer, even here. So here's my question, illustrated with an example:
We have a negatively ...
- 109
3
votes
1
answer
245
views
Why is Piperidine more basic than Pyridine? [duplicate]
Piperidine, which has sp3 carbons attached to it, experiences an increase in electron density on the nitrogen atom, making it more basic. However, when we look at the resonating structures of pyridine,...
- 41
0
votes
1
answer
177
views
Why is phosphoric acid a weak acid?
What is the reason for the phosphoric acid $\ce{H3PO4}$ being a weak acid despite having a structure similar to that of sulfuric acid $\ce{H2SO4}?$
I found some sources claiming that the resonance of ...
- 19
3
votes
0
answers
48
views
TsOH and 5% NaHCO3 Interaction: Unexpected Dark Green Color
Here's the brief:
I synthesized alkyl gallates (ethyl gallate, butyl gallate, and amyl gallate) using Fischer esterification.
I used TsOH instead of concentrated H2SO4 as the catalyst.
After ...
- 155
1
vote
1
answer
100
views
Why Is HOI a weaker acid than HOCl?
In HOI, the oxygen would be more negatively charged than the oxygen in HOCl because iodine is less electronegative than chlorine. Thus the O-H bond in HOI would be more polarized, which would mean it ...
- 169
0
votes
0
answers
63
views
Explaination of order of leaving groups
In Solomons' Organic Chemistry, in a section discussing leaving groups, it is stated that$-$
Among the halogens, an iodide ion is the best leaving group and a fluoride ion is
the poorest:
$$I− > ...
- 171
1
vote
3
answers
180
views
pH at maximum concentration of a certain species (Phosphoric acid) [closed]
I am trying to find the pH at which $[H_{2}PO_{4} ^{-}]$ is maximum by only knowing the pKas.
I have tried to derive an equation using kinetics but it failed [1].
After taking a look at the Sillén/...
- 84
2
votes
0
answers
86
views
Why aren't aldehydes more acidic than saturated alcohols?
Aldehydes (pKa ~17-20) and ketones (pKa >20) are worse acids than alcohols (pKa ~15-16). I have seen that the equilibrium of aldehydes (and ketones) with their hydrates greatly decreases pKa values ...
- 97
1
vote
4
answers
159
views
Pedantic: Is NH4(+) or NH4Cl the acid?
This is pedantic and trivial query.
For this below reaction,
$$\ce{NH4Cl + NaOH -> NH3 + H2O + NaCl}$$
we can reduce it to its net ionic equation
$$\ce{NH4+ + OH- -> NH3 + H2O}$$
Is it correct ...
-1
votes
2
answers
62
views
Two different reaction pathways that explain the non-neutrality of a dissolved salt
So the problem is this: is the sodium acetate acidic, basic or neutral?
One of my textbooks (ATAR Notes chemistry) says in solution, acetate simply (due to its negative charge) accepts protons and ...
2
votes
1
answer
117
views
Naunyn's definition of acids and bases
An excerpt from the online lecture I'm studying is as follows:
1880-Arrhenius defines an acid as a substance that , when dissolved in >water, produces an increased concentration of hydrogen ions.
...
- 29
2
votes
0
answers
59
views
Phase diagram of ammonium hydrosulfide, a volatile salt
Salts (ionic compounds) usually have low volatility due to the strong ionic bond.
However, there are exceptions. Smelling salts decompose and release ammonia gas.
What is "volatile"?
If a ...
- 972
0
votes
0
answers
48
views
Secondary alkyl halides and strong base: Sn2 vs E2
I got this question from the PYQs of a college entrance exam. According to the answer key, 4-chloro-3-methylpent-1-ene reacts with NaOH in water to give 4-hydroxy-3-methylpent-1-ene via the SN2 ...
1
vote
2
answers
234
views
How does the concentration of H+ ions in HCl change as the pH changes? [closed]
I am helping my friend's 16 year old prepare for her GCSE chemistry exam. This question was on an AQA GCSE Chemistry past paper but I do not know the year and could not find a markscheme for it on the ...
- 247
0
votes
1
answer
235
views
Amphoteric character of V2O5
In my NCERT textbook, in the chapter 'The d- and f-block elements', the last paragraph under oxides and oxoanions of metals goes like this:
$(...)$ $\ce{V2O5}$ is, however, amphoteric though mainly ...
- 828
1
vote
0
answers
39
views
Trends in pKb for both acetic acid and water
I am trying to rationalise a result that I have recently measured in the lab. I'm measuring the pKb of different compounds in anhydrous acetic acid, using the procedure outlined in this paper (https://...
- 11
-2
votes
2
answers
93
views
Reaction between copper rod and carbon rod in hydrochloric acid [closed]
The situation is this: a copper rod and a carbon rod, touching each other, are submerged in HCl(aq). We're asked to describe the reaction that occurs, but as far as I can see, there's no reaction? The ...
- 5
4
votes
0
answers
279
views
Exchange of Fluorine to Oxygen for Fluorophosphonic acid by silylating agents or other methods?
[Warning, long post!]
Dear all,
I am confronted with a seemingly easy transformation. I want to remove a fluorine atom at a fluor phosphonic acid salt. The usual method to achieve this is the basic ...
- 829
0
votes
1
answer
84
views
pH in a buffer of Glycin and HCl
I am struggling with a task. I have the amino acid Glycin with pKa1=2,3 and pKa2=9,6.
I have 1.0 liter 0.20 mol/L solution of glycin. I add 0.1 liter 1 mol/L HCl solution. What is the pH in this ...
- 19
0
votes
1
answer
84
views
Hydrogen–deuterium exchange in 1,4-benzoquinone
Problem
Find number of deuterium exchanges in the following compound.
Solution
Question
I have been taught that hydrogen attached to the carbon which is directly or indirectly in conjugation with ...
- 131