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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Thermometric titration for a graph of temperature against volume of titrant
Why would you extrapolate the two best fit lines up to the point where they intersect?
Image Source- Wikipedia
I know that this is the endpoint where all alkali or acid is neutralized (or just when ...
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Why is PCl3 acidic? [closed]
Why is it that when adding PCl3 into distilled water, the solution becomes acidic? What exactly is the reaction occurring? Must it not be neutral as the PCl3 is molecular, or then P has a lone pair of ...
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How useful is thymol blue (acid) as an indicator?
The pH range of thymol blue (acid) is 1.2-2.8.. This pH range seems pretty useless. Generally, the sudden change in pH for SA-SB titration occurs in the range of 4-10; the sudden change in pH for SA-...
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Reason behind colour change of indicators [duplicate]
We know that for testing acids and bases we use the indicators. For eg. Acid turns blue litmus red and base has no effect on the blue litmus. Similarly colours are also seen in phenolphthalein, methyl ...
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Propylene glycol smells like alcohol [closed]
I got a batch of propylene glycol and suddenly the smell became like acetone or alcohol is there away to get rid of the smell without affecting the pg
Sorry my English is not good
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Should I write formula for oxalate or oxalic acid while balancing a redox reaction using the ion-electron method?
Problem:
Balance the following reaction using the ion-electron method:
$$\ce{H2C2O4 + KMnO4 + H2SO4 -> CO2 + MnSO4 + K2SO4 + H2O}$$
My book's solution:
Oxidation half-reaction:
$$\ce{C2O4^2- -> ...
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46
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How to find pH for acetate buffer?
Calculate the pH of the solution that results when $\pu{40.0 mL}$ of $\pu{0.100 M}$ $\ce{CH3COOH}$ is mixed with $\pu{30.0 mL}$ of $\pu{0.200 M}$ $\ce{NaCH3COO}.$ $K_\mathrm{a}(\ce{CH3COOH}) = \pu{1....
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"The neutralization reaction between a weak acid and a weak base never occurs to the right of the equilibrium" - what does my book mean?
[Book: Chemistry-2nd Paper (Class XI-XII) January 2020 by Hajari & Nag, Bangla version, p-410]
I don't think my book is using the terms "right" and "equilibrium" correctly. If ...
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why did the temperature change when the first few measures of slaked lime were added to the vinegar [closed]
I need to describe any links between the number of measures of slaked lime added , pH and the temperature . What was the pattern for the pH and temperature as more measures were added ?
Did the ...
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Etching polished marble?
My wife's cousin owns a marble company, so when they told us we could have free cutoff pieces, we thought it could make a cool patio.
Problem is, they're SUPER slippery.
Someone suggested pouring acid ...
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1
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Balanced reaction to Cr given H+ [closed]
The troublesome nature of this post, is that I was given very little information to work with:
"The metal chromium (Cr) reacts with an acid, to create Cr^+3 ions, and hydrogen gas.
Show the ...
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Can oxygen atoms be regarded as a Lewis acid?
Although both oxidants and Lewis acids can steal electrons, they work in different ways. Oxidants acquire electrons via ionic bonds or polar covalent bonds, while Lewis acids form dative bonds with ...
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Does the solvent used affect basic strength?
In this question, it is explained how basicity and nucleophilicity are different and how the solvent used affects nuclephilicity.
What I wondered was whether there would be a difference in the basic ...
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Titration using OTC washing soda (sodium carbonate.) should I use 105.9888 g/mol (anhydrous) or 286.1416 g/mol (decahydrate)?
Looking to make up a little toy/non serious titration to approximately measure the concentration of household acids using sodium carbonate as my standard solution. Doing a quick internet search ...
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How does CO2 'dissolve' in water (or blood)?
I'm trying to understand CO2 dissolved in blood, carbonic acid and the bicarbonate ion. I think of 'dissolving' as in NaCl dissociating into Na+ and Cl- ions sloshing around in water. CO2 isn't ...
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How much Calcium Hydroxide to manufacture calcium formate?
First, I have no experience with stoichiometry.
I currently manufacture calcium formate for a specific use because here in my country, it is very difficult to get calcium formate in small quantities. ...
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What is the pKa of the O-17 hydronium ion?
At low concentrations of a conjugate acid/base pair in aqueous solutions, the Henderson-Hasselbalch equation gives a good approximation of the ratio of acid and base:
$$ \frac{[\ce{A-}]}{[\ce{AH}]} = ...
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Why Aren't Alcohols Weak Bases?
I was reading about alcohols being weak acids because they are deprotonated in water, presumably because the $O-H$ bond is being overcome by hydrogen bonding between $H$ in the hydroxyl group and $O$ ...
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Can I use baking soda to precipitate soluble copper out of a citric acid bath into a non-soluble form for disposal
I may be at the wrong forum with such a basic question but trying to ferret out the answer on Google has not been productive. Apologies in advance. I do art metal, working almost exclusively in ...
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Can chloride donate an electron pair to silver(I)?
According to the Lewis dot structure of $\ce{Cl-}$, $\ce{Cl-}$ has octet fulfilled and should be able to donate a pair of electrons as it is a Lewis base. The Lewis dot structure of $\ce{Ag+}$ seems ...
user123510
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How to make a paste out of vinegar?
I am trying to make a smooth vinegar cream for short term use of up to about 3 months (i.e. no preservatives are needed if stored in a cool place).
Vinegars such as apple cider vinegar or pure acetic ...
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pH of 30 mM sodium lactate in water at room temperature
At https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-lactate#section=pH&fullscreen=true it is stated that a 20% sodium lactate has pH 6.5 to 7.5. With a MW stated to be 112.06 this should be ...
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Why did anyone invent the concepts of acids and bases? [closed]
I am home-schooling my son in first-year Chemistry, and I am struggling to teach Acids and Bases in a rewarding way.
I am not new to Chemistry. I went to grad school in Physics and I even taught High ...
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Why is there H^+ ions in Hcl? [closed]
I am new to chemistry, just learning the basics. So, my question is: Hydrogen and chlorine form a covalent bond, so shouldn't they both be negative as they both got an electron by sharing? Why is H ...
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pKa of methylene protons in cycloheptatriene vs cyclopropene
The $\mathrm{p}K_\mathrm{a}$ values of methylene protons in cycloheptatriene vs cyclopropene are found to be 60 and 36, respectively.
From what I understand - both conjugate bases are non-aromatic (...
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How to make a thin layer of crystalline barium titanate on copper substrate?
Is it possible to create a thin $\ce{BaTiO3}$ crystal layer on a copper plate by putting the plate in a beaker, pouring in heated hydrofluoric acid that has been saturated with $\ce{BaTiO3}$ powder ...
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Can ammonium salts react with insoluble bases, such as copper(II) oxide?
Can ammonium salts react with insoluble bases, such as copper(II) oxide? Textbooks and preliminary searches on Google all yield answers that give reaction of ammonium salts with strong alkalis instead....
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What is the chemical equation of lemon titrated with sodium hydroxide? [closed]
What is the chemical equation of citric acid titrated with sodium hydroxide (titrant), given that the molecular formula of citric acid is
$$ \ce{C3H6O(COOH)3} $$
and the molecular formula of sodium ...
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Why is carbon monoxide non-Brönsted-basic in aqueous solution when it has a lone pair on carbon?
Carbon monoxide is not protonatable in aqueous solution; a quick Google search even leads to a paper that talks about using carborane acids, i.e. extreme superacids, to protonate the molecule.
However,...
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My particles won’t separate without neutralizing the solution. I want to understand why?
I etched active carbon with a concentrated KOH solution and added HCl to neutralize the KOH. Separeted the particles with centrifuge at 4000 rpm. They should be micron sized.
My boss asked me to stop ...
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Acidity and Basicity of titrate and titrant in Acid-Base titration
I want to know that do we always use monoprotic acid and bases in the Acid-Base Titration. And, if the answer is No. Then, I am confused in the definition of Equivalence Point, because I had seen on ...
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Could you explain why the iron (ii) carbonate re-dissolves and how this can be described as an acid/base reaction , by mixing FeSO4 and Fe2+ salts
Iron(II) carbonate is insoluble but in class you might not have seen any solid. The precipitate often redissolves because the iron(II) sulphate has acid added to it. Can you explain why the carbonate ...
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Discrepancies in using pOH vs pH to solve H+/OH- concentration change problem
I found an extremely confusing problem in one of the problems we did in class for general chemistry. This was the question:
How many moles of $\ce{H3O+}$ or $\ce{OH-}$ must you add per liter of $\ce{...
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1
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Is it possible for a long carbon chain to have both acidic and basic groups?
I was reading about a zwitter ion and I had a thought that is the same possible for an acidic and basic groups. Like a very long carbon chain with a basic group and an acidic group on either sides, I ...
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Reaction between sodium hydroxide and phosphorus trioxide
My chemistry textbook [1], chapter Periodic Properties of Elements, section p-Block elements — formation of oxides suggests that the reaction is
$$\ce{P2O3 + 2 NaOH -> 2 NaHPO3},\tag{R1}$$
but ...
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1
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Calculate the volume of acid needed to change the pH of an unbuffered or buffered solution using a strong acid, weak acid, and diprotic acid
It's been a while since I've been in a chemistry class and I'm having a hard time figuring this out. I need to reduce the pH of a solution from 5 to 4. There are 3 acids I can use to do this: 20% v/v ...
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Do I need to 'neutralise' iron/steel/metal with a base after removing rust with acid?
I've never asked a question here before but these forums seem to have some extremely knowledgeable people so I thought I'd give it a try. I know it's a 1st grade question but I honestly don't have the ...
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What is the product of the following reaction(different sources give different answers) [closed]
$$\ce{FeS +dil HNO3}$$
$$\ce{FeS +conc HNO3}$$
I got different answers to these reactions in different sources
Source1 Jd lee:
Source 2 Op Tandon:
Can anyone please explain which is the correct one ...
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Between compounds having same functional groups, why does the one with greater -I effect have higher acidic strength
Consider the two compounds $\ce{FCH2COOH}$ and $\ce{ClCH2COOH}$.
Since fluorine is more electronegative than $\ce{Cl}$ it will show a greater –I effect.
It will pull the the electrons closer towards ...
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How much calcium hydroxide is needed to raise the pH of an aqueous sulphuric acid solution?
Lets say dissociation constants $K_{\mathrm{a}1}$ & $K_{\mathrm{a}2}$ of $\ce{H_2SO_4}$ in water are $1000$ and $0.012$ respectively. So the first dissociation step happens completely:
$$\ce{ ...
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Using bond energies to calculate the released energy of a neutralization reaction
I am trying to make a simulation of a neutralization reaction that simulates the change in enthalpy as the reaction progresses. The strategy I have decided to go with is using the energy of the ...
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1
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Finding Ka of an Acid from incomplete titration data
I'm studying for chem olympiad and have a question about a problem from a past year's test:
A pure sample of a monoprotic acid is dissolved in water.
The sample is titrated with sodium hydroxide ...
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Creating sodium tetraborate decahydrate from boric acid
I would like to obtain sodium tetraborate decahydrate (borax) from boric acid
(note not the other way around that is answered here: Creating Boric Acid from Borax and Hydrochloric Acid)
Perhaps use ...
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Would the addition of Citric and Phosphoric Acid or Potassium Carbonate to agricultural water supply result in health/safety concerns?
I am doing a small greenhouse project for fun. As a side benefit of this project, I was hoping to consume the food that I will be producing. I have been checking all of the products that I will be ...
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How does pH affect an extraction problem
I am not sure how to understand when pH will affect a given problem regarding extraction. For example, in a problem given that K$_D$ of the reaction is $1.86$ I am asked to calculate:
(a) How much ...
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Reaction between concentrated sulfuric acid and sodium bromide
What are the products of the reaction between sodium bromide and concentrated sulfuric acid?
I did the question like this:
$$
\begin{align}
\ce{2Br- &-> Br2 + 2e-} \tag{R1.1} \\
\ce{SO4^2- 4H+ ...
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1
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Possible Plumbing Acid through Leaky Pipe in Floating Ceiling, How to Test/Clean?
So I had a plumber in the other day, and I don't know if he used acid drain cleaner or not. The pipe where the possible leak is, is over some drop ceiling (vinyl or expanded polystyrene).
Before I go ...
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1
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Old sodium hydroxide based drain cleaner become stony and brown, not hydrosoluble anymore
My drain was clogged and I used an old sodium hydroxide based drain cleaner to free it. The cleaner was quite old and inside it was brownish and monolithic, not a bunch of small white spheres anymore.
...
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1
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What will be the structure of cysteine at pH=4? [closed]
As per my understanding since pKa of RSH and the amino group is >4 hence they would be in cationic form while the acid should be in anionic form. So charge on cysteine would be +1. But while ...
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1
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Why is sodium bisulfate acidic? [closed]
So, as I know, the rule says that if you get a salt from strong acid and strong base it should be neutral. In this situation with sodium bisulfate and also trisodium phosphate we get an acid salt, ...
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