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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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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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 ...
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Is it possible to calculate the theoretical rate of reaction?
I am conducting an experiment where I will be changing concentration (0.2 mol/dm3, 0.4 mol/dm3, 0.6 mol/dm3, 0.8 mol/dm3, 1.0 mol/dm3) and seeing how that affects the rate of reaction for a reaction ...
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Why are bases corrosive?
If I understand correctly, an acid corrodes things because the hydronium ion attracts electrons away from whatever it is reacting with. Do bases corrode things in a similar manner? with the metal ...
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Is HCl in salt form reactive with metallized aluminium plastic film? [closed]
I’m in the process of packaging an amino acid that contains HCl in salt form. The mixture is 60% base and 40% HCl salt.
Will this react to metallized aluminium plastic?
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Why are alcohols considered slightly basic (based on pKa values)?
I understand why it makes sense for an alcohol to be slightly basic given the hydroxyl group and the electron-donating properties of the alkyl chain. But I'm a bit confused as to why it's the case ...
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Hydrolysis of $A_3B$ type weak acid-weak base salt
I know the formulae for weak acid-weak base salt of AB type. A peculiar question made me ask this. Do the formula for derived for AB type also hold for A3B type sal.
For example:
This is the question, ...
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Could ammonium azanide exist?
In my first high school chemistry class, I misremembered nitrate as being $\ce{NH2-}$, rather than $\ce{NO3-}$, and wrote down a formula for "ammonium nitrate" that was $\ce{NH4NH2}$ (rather ...
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How to identify an organic base?
According to the answer key, trimethylamine (iii) and ethanolamine (iv) are considered organic bases, whereas ammonium (i) and acrylamide (ii) are not:
From my understanding, an organic base has an ...
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Change in pH/acidity of vinegar after adding aqueous NaCl
There's a question in my (grade 10) textbook asking to determine what will happen to the pH/acidity of vinegar if a solution of sodium chloride in distilled water is added to it drop by drop. The ...
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Find the pH of a solution obtained by mixing 100 ml 0.1m Na3PO4 and 100 ml 0.1 M NaH2PO4. Given that H3PO4: [Κα₁ = 10^-4, Κα₂ = 10^-7, Каз = 10^-11] [closed]
So, my query is that since NaH2PO4 is a weak acid, and Na3PO4 is a basic salt, wouldn't they react? Another theory was that since NaH2PO4 is a weak acid and Na3PO4 is a salt of strong acid and NaH2PO4,...
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Can phosphorous penta hydroxide [P(OH)5] exist? [closed]
I was looking at the oxyacids of Phosphorous and it is given that (in Wikipedia article of "Phosphorous acid"), some of these acids (Eg: $H_3PO_2$ and $H_3PO_3$) exist in a dynamic ...
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What is happenning with that single hydrogen in Phosphorous acid?
As an oxyacid, Phosphorous acid intuitively should have the structure
since the hydrogens should be on the oxygens.
However, the major form of this acid is actually
with the hydrogen attached to the ...
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Aquatic chemistry, pH and alkalinity
Hope you can help me with an aquatic chemistry question.
I have different types of water of different pH and alkalinity.
pH, alkalinity, HCO3 and CO2 concentrations are known.
I need to calculate the ...
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Why doesn't acid dissociation always have K>1?
Acid dissociation is usually exothermic, and it has an increase in entropy, so the change in Gibbs free energy should be negative. So why isn't always $K_\mathrm{a}>1$ in accordance with $\Delta G^...
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What is the pKa of choline chloride?
I am looking for the pKa of choline chloride, which should be higher than 7 (around 10?), but I cannot find any reference value.
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How does increased polarity of O-H increase acidity? Shouldn't it reduce it as bond strength increases?
A polar bond will be stronger than a relatively less polar bond. So how does increasing polarity of O-H bond ever increase acidity. Shoudn't it make it harder to release H+ and become less acidic.
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Question about the differences of white and grey NaH properties
We are having some problems with the next reaction in our lab. As you can see, is the sulfonylation of an indole in which we use NaH (60% dispersion in mineral oil) as a base. This reaction goes with ...
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Acid base titration molar ratio [closed]
Consider the following neutralisation reaction:
$$ \ce{2HNO3 + Ba(OH)2 -> Ba(NO3)2 + 2H2O} \tag{1} $$
I would be glad for help in how to solve this problem with $c_1V_1 = c_2 V_2$, because the ...
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Common Ion effect with sulphuric acid
Sulphuric acid dissociates completely (H2SO4 -> HSO4⁻ + H⁺).
Its product HSO4⁻ has a pKa of 1.92 which should then dissociate partially into SO4²⁻ and H⁺.
I was trying to find out the pH of a 0.05M ...
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Question on electron density
I was working with ammonia ($\ce{NH3}$) and phosphine($\ce{PH3}$). Both have lone pair electron. But $\ce{NH3}$ is stronger base (Lewis base) than $\ce{PH3}$.
I was told by my instructor that it is ...
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Why is the ionic product of water also the equilibrium constant of dissociation of water?
This answer presents a derivation of the value of ionic product of water at $25^{\circ}\text{C}$.
The relation $K_\text{eq} = \operatorname{e}^{-\frac{\Delta_\text{r}G^{\circ}}{RT}}$ is used for the ...
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Is boric acid aqueous solution corrosive to stainless steel? [closed]
I'm thinking of trying an aqueous boric acid solution in a nebulizer for a sinus infection, in a similar strength as for eyewash (anywhere from 1 tsp. in 4 oz. to 1 tsp. in 32 oz.). My nebulizer has a ...
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Making Sodium Citrate
I've been trying to make Sodium Citrate and I've seen online people saying just react sodium bicarbonate with citric acid in water (with correct ratios) and boil off/remove water once the reaction has ...
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How long would it take fluoroantimonic acid to melt through a tiger's body? [closed]
I'm writing a story in which a character throws a knife containing fluoroantimonic acid contained within hydrofluoric acid, which is itself contained within fluorinated plastic, into a tiger's mouth. ...
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Why is the lysine side chain more basic?
As per PubChem: $pK_1 = 2.18$; $pK_2 = 8.95$; $pK_3 = 10.53$ at 38 °C, indicating that the side chain amino group is deprotonated at a higher pH, indicating it is more basic. I tried to justify this ...
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Why are buffer solutions not neutral
I am very confused about buffer solutions and I have lots of ideas about them which don’t integrate together so I really can’t tell which are correct and which are wrong. That being the case it’s ...
