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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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 a ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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,...
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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 ...
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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 ...
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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 ...
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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,...
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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 ...
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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 ...
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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 ...
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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:
$$I− > ...
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pH at maximum concentration of a certain species (Phosphoric acid) [closed]
I am trying to find the pH at which $[H_{2}PO_{4} ^{-}]$ is maximum by only knowing the pKas.
I have tried to derive an equation using kinetics but it failed [1].
After taking a look at the Sillén/...
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Why aren't aldehydes more acidic than saturated alcohols?
Aldehydes (pKa ~17-20) and ketones (pKa >20) are worse acids than alcohols (pKa ~15-16). I have seen that the equilibrium of aldehydes (and ketones) with their hydrates greatly decreases pKa values ...
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Pedantic: Is NH4(+) or NH4Cl the acid?
This is pedantic and trivial query.
For this below reaction,
$$\ce{NH4Cl + NaOH -> NH3 + H2O + NaCl}$$
we can reduce it to its net ionic equation
$$\ce{NH4+ + OH- -> NH3 + H2O}$$
Is it correct ...
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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 ...
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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.
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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 ...
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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 ...
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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 ...
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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 ...
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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://...
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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 ...
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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 ...
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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 ...
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