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 ...
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1answer
37 views
When using a “dilute hydrochloric acid” solution, how diluted should it be?
Quite often when reading through some instructions or documentation or an outline that I've found online (EG: acid-base extractions), theres a step that involves using a "dilute hydrochloric acid ...
-1
votes
0answers
18 views
Molarity and Concentration [on hold]
What is the molarity of the solution
produced when 85.6 g of hydrochloric acid
(HCl) is dissolved in enough water to
prepare 385 mL of solution?
In the question above do i need to find concentration ...
3
votes
2answers
47 views
Comparing acidity between groups
I tried to do this using the stability of conjugate base. I can see (2) will be most stable due to resonance however my confusion lies in (1) and (3).
While in (3), the negative charge is unstable but ...
-1
votes
1answer
55 views
Does HCl evaporate at room temperature?
So my question is...lets say that somebody pours hcl (30%) in the toilet and on bathroom floor.Does the acid evaporate after a while it is it possible that it's still present after like month?
Thank ...
-2
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0answers
16 views
General Chemistry Titration [closed]
Can anyone help me with the following question? I tried using $\mathrm{K_w/K_a = \frac{x^2}{10^{-pOH}}}$, I also tried using the pH value $11.00 = -\log(K_a) + \log(\frac{x}{[\ce{HCN}]})$, but I can't ...
-2
votes
0answers
33 views
Dissolved CO2 and buffer capacity of water: how quickly does it work? [closed]
Let's say we have a system that dissolves $\ce{CO2}$ in tap water. In my understanding, a small portion of dissolved aqueous $\ce{CO2}$ combines with water to form carbonic acid. Given some fixed ...
-1
votes
2answers
26 views
Calculate pH of a mixture of a strong base and acid. Knowing only the pH, wt/v%, and volume of both solution. [closed]
Title explains all. I have been stuck on this for an hour and for some reason cannot understand it. I have tried to do an ICE table but get stuck halfway as I do not know whether I would use the w/v ...
1
vote
0answers
33 views
Why is antimony pentafluoride a stronger Lewis acid than phosphorus pentafluoride or arsenic pentafluoride?
How can these relative reactivities as a Lewis acids be rationalized:
$$\ce{SbF5 > AsF5 > PF5}$$
One simple argument could be the size of the $\ce{Sb}$-center: Because it is bigger than for ...
0
votes
0answers
25 views
pH calculation of salt in acid
A person go to an all-you-can eat restaurant but eat a little too
much and get heartburn. He returns to his room, looking for a remedy. He takes $3$ teaspoons of milk of
magnesia, which contains $...
-1
votes
0answers
26 views
pKa Value Of Strong acids [duplicate]
Strong acids are completely disassociated into ions in water and the reaction goes to completion. Then how come they also have a pKa value too?? Isnt calculating the equilibrium constant only for ...
2
votes
0answers
44 views
Comparing the basicity of benzamide and acetamide
What if we were asked to compare the basicity of benzamide and acetamide?
Which one of them would be more basic? I read somewhere on the internet that benzamide must be more basic than acetamide due ...
2
votes
1answer
35 views
pH throughout a titration
Estimate the $\ce{pH}$ of the solution that results when $\ce{75.0 mL}$ of $\ce{0.275 M HCl}$ is added to $\ce{50.0 mL}$ of $\ce{0.275 M Na2HPO4 (aq)}$.
My book gives the successive $\ce{Ka}$ values ...
1
vote
1answer
49 views
Why doesn't pH = pKa1 in the buffer zone for this titration?
Below is an image from my textbook representing the titration curve for the titration of $5.00\ \mathrm{mL}$ of $0.010\ \mathrm M$ $\ce{H2S2O3}$ with $0.010\ \mathrm M$ $\ce{KOH}$, which has $\mathrm ...
4
votes
0answers
55 views
Comparing Acidic Strength of H3PO4 and H3AsO4
The $pKa$ values for H3AsO4 and H3PO4 are $2.30$ and $2.12$ which indicate that H3PO4 is a stronger acid compared to H3AsO4. I looked up their electronegativity values to find that they are almost the ...
-1
votes
1answer
26 views
Acid neutralization [closed]
I am working on a biogas plant,
digester volume 3000 liter,
right now pH condition is acidic at 4.00
my requirement is to maintain pH to 6.50 to 7.20
what should I do?
some suggestions are there like, ...
-2
votes
0answers
38 views
Monitoring the pH level while neutralizing a base with acid
I'm working on an experiment that entails the neutralization of a base with an acid, and I don't really have any chemistry experience other than what I was taught in high school, which was a very long ...
1
vote
0answers
21 views
Order of lewis acidity for BBr3, BCl3, BMe3, BH3, BPh3?
In case of $\ce{BCl_3}$ vs $\ce{BH3}$, which one is the controlling factor?
1) Is it p-pi p-pi interaction in $\ce{BCl_3}$ that makes it weaker than $\ce{BH3}$?
2) Or is it the -I effect of $\ce{Cl}...
-2
votes
1answer
17 views
Comparision of acidic strength of benzoic and peroxy benzoic acid [closed]
Out of the two which one is stronger acid ?
1
vote
1answer
43 views
Can an ant etch a hole in a tent with formic acid?
Given a polymer foil tent, could ant's formic acid help to etch a hole in it? I thought of a polyester or polyamid foil. If one ant's acid is not enough, they come as team.
2
votes
0answers
24 views
How to determine charge of compounds in solution with many amphoteric functional groups?
I am curating a metabolic model that has compounds such as NADH/NADPH/Etc. that have multiple ionize-able hydrogens. Normally with amino acids there are only a few hydrogen with varying pKas that ...
-2
votes
1answer
29 views
Why does Ca(CH3CH2CH2COO)2 dissolve in HCl and not in NaOH? [closed]
I do not understand why a strong base, such as NaOH would not dissolve a solid such as this. There would be a double displacement in which you form Ca(OH)2 and NaCH3CH2COO (aq).
Why would HCl ...
0
votes
0answers
15 views
What is the “coefficient of ionization” or “ionization coefficient”?
The question got bumped and I looked at it. The OP seems to use the two terms coefficient of ionization and ionization coefficient interchangeably and assigns the variable $\alpha$. The problem is in ...
-1
votes
0answers
35 views
What is the significance of water being >50% protonated/deprotonated when measuring pKa values?
In water, we can measure the $\mathrm{p}K_\mathrm{a}$ of an acid only if the acid does not completely protonate water to give $\ce{H3O+}$ or completely deprotonate it to give $\ce{OH-}$. We are ...
0
votes
1answer
40 views
How to calculate the concentrations of conjugate species present in the solution of diprotic acid?
Calculate the concentration of $[\ce{SO_3^-^2}]$ present in 0.010M solution of $\ce{H_2SO_3}$ in pure water?
($Ka_1=0.017)$, ($Ka_2=10^{-7.19}$)
I found this approach in reference text for solving ...
-1
votes
1answer
30 views
Why don't soluble gases that evolve in a reaction remain in solution?
Take for instance the following process:
$$\text{2NaCl}_{\ (s)} + \text{H}_2\text{SO}_{4 \ (aq)} \to \text{2HCL}_{\ (g)} + \text{Na}_2\text{SO}_{4 \ (aq)} $$
Why does the evolved gas leave the ...
-1
votes
0answers
34 views
How to calculate the pH of 1*10^(-8) M HCl [duplicate]
Just wondering how to calculate the pH of strong acids when the concentration is lower than 10^-7 M.
0
votes
0answers
41 views
Henderson hasselbalch derivation for conjugate acid
My understanding is that the pKa of a base is the pKa of its conjugate acid. I can derive the HH equation for an acid:
$$\ce{HA + H2O <-> H3O+ + OH-}$$
$$\ce{Ka = [H3O+] [OH-] / [HA]}$$
$$\...
0
votes
0answers
32 views
Compare acidity of acetylene and methyl fluoride
Which is more acidic - acetylene or methyl fluoride - and why?
As we know we check acidic character of acetylene on basis of %s character while $\ce{CH3F}$ on basis of -I effect, so how can we ...
3
votes
1answer
421 views
Why is ammonia less acidic than terminal alkynes?
Here's a picture from Organic Chemistry by Solomons, Fryhle & Snyder :
Why is it that ammonia is less acidic than terminal alkynes even though water, and even alcohols, are more acidic than them?...
-1
votes
1answer
14 views
% Purity Calculation [closed]
An impure sample of calcium oxalate with a mass of 0,803g, is titrated with 15,70cm3 of a 0,101 potassium permanganate
How do I calculate the % purity of the calcium carbonate in the original sample
0
votes
0answers
13 views
EQPt pH of a Monoprotic Acid-Base Titration: Product of Molarites Over Their Sum
Context
The Henderson-Hasselbalch equation is as follows. $$pH=-\log\big(K_a\big)+\log\bigg(\frac{[A^-]}{[HA]}\bigg)$$ One may follow its derivation in order to understand how it came to be, yet ...
1
vote
0answers
26 views
Acid-Base extraction - Ammonium hydroxide precipitate turns to semi-solid substance
I'm attempting to extract some alkaloids from plant matter using the acid-base extraction technique. I'm using 28% concentrated HCl as the acid, Ether as the organic solvent, and Ammonium Hydroxide as ...
3
votes
1answer
174 views
Which formula can be used to calculate the exact hydronium concentration present in sodium hydrogen carbonate solution?
Which formula can be used to calculate the exact hydronium concentration present in sodium hydrogen carbonate solution ?
$$\ce{[H3O+]}=\sqrt{K_\mathrm{a1}K_\mathrm{a2}}$$
$$[\ce{H3O+}]=\sqrt{\frac{...
1
vote
0answers
31 views
Why is perchloric acid stronger than perbromic acid? [duplicate]
Since chlorine has a larger electronegativity than bromine, why is perchloric acid a strong acid, while perbromic acid is not? We clearly see that electronegativity affects an acid's strength with ...
-1
votes
1answer
33 views
Ionproduct of Water [duplicate]
The ionproduct of pure water is well known to be
$$
K_{\rm W} = \left[ {\rm OH^-} \right] \left[ {\rm H_3O^+} \right] = 10^{-14}
$$
at some standard conditions (I think 25°C).
However having some ...
2
votes
3answers
86 views
Why do electron donating groups decrease the acidity of aromatic carboxylic acids?
If we look at the resonance structures of benzoate anion, we would see that some amount of positive charge is present on the ring and this charge can get delocalised on the ring, like this:
Now, if ...
0
votes
0answers
32 views
Equation of state (EoS) for liquid density, in terms of pressure, temperature and concentration
I'm currently in need of an equation to calculate density of aqueous solutions such as acids, bases, and salts. The equations to calculate liquid density that I have found so far do not account for ...
2
votes
1answer
46 views
Is it correct to say H2SO4 behaves like an acid in this reaction? [closed]
I came across this equation :
$$\ce{ZnCO3 + H2SO4 → ZnSO4 + CO2 + H2O}$$
I wanted to know if $\ce{H2SO4}$ behaves like an acid in this reaction?
How do we generally determine if a compound acts as an ...
0
votes
1answer
33 views
How much muriatic acid to dissolve cinder block? [closed]
Can a cinder block be dissolved in hydrochloric (muriatic acid) ?
Also if it can then how much hydrochloric acid will be needed ?
-1
votes
1answer
33 views
Confusion About Acid/Bases That Don’t Follow the Arrhenius Definition [closed]
I understand that acidity is merely a reflection of how many free hydrogen ions are in water, and basisicity is just a reflection of the number of hydroxide ions, but I don’t understand how this ...
1
vote
0answers
111 views
Citric acid rust removal and neutralization
I'm currently removing rust from steel with citric acid dissolved in water. I generally use a wire brush as the final treatment to remove any surface rust that the acid loosened up. The pieces under ...
-1
votes
1answer
56 views
How to calculate pH of the Na2Co3 solution given ambiguous Ka values
This is the exact question i faced on exam.
Calculate the pH of $\pu{0.05 M}\ \ce{Na2CO3}\ (\ce{H2CO3}: K_\mathrm{a,1}= 4\times 10^{-7},\ K_\mathrm{a,2}= 4.7\times 10^{-11})$
Solution
$\ce{Na2CO3 -&...
3
votes
1answer
59 views
Phenol and Deuterated Sulphuric Acid
What happens when phenol reacts with $\ce{D2SO4}$ in presence of $\ce{D2O}$?
How many hydrogens in total are replaced by deuterium?
Is the hydrogen of the hydroxyl group and three hydrogens ortho ...
1
vote
1answer
98 views
Group 15… Lewis Acid, Lewis Base or Not At All?
I am a long-time reader of this forum, but this is my first time post. I am a chemistry undergrad with a question about Lewis acidity or basicity of Group 15 compounds.
I know Lewis acids act as an ...
3
votes
1answer
31 views
About nitrogen acidity in function groups
I have a compound and it has several nitrogen atoms. I wish to know how do we differentiate between the basic and acidic nitrogens?
This is an example compound:
1
vote
0answers
26 views
Is there a thermodynamic explanation for how a substance behaves based on its pKa and the solution’s pH?
If the pH of the solution is lower than the pKa of the compound, then the compound will be protonated, because pH is a measure of the concentration of protons, and low pH means a high proton ...
3
votes
0answers
45 views
Why AlCl3 more acidic than FeBr3?
In compounds with lone pairs or with charge it is easy to predict acidity of compounds but how to describe acidic nature of such ($\ce{FeBr3}$, $\ce{AlCl3}$) transition element compounds ?
-1
votes
1answer
65 views
Is an acid strong when its conjugate base is strong or weak? [duplicate]
It is often said that stronger acids have weak conjugate bases and vice versa. Yet also in organic chemistry if an acid is proven to have a stable conjugate base it is said to dissociate more, which ...
5
votes
2answers
137 views
Calculate pH of a weak acid and weak base neutralization reaction
I'm an industrial pharmacist needing some help with some chemistry basics.
I'm trying to calculate the theoretical pH of an effervescent preparation containing 2 mmol citric acid ($\ce{H3C6H5O7}$), 4 ...
1
vote
1answer
27 views
Why is there only a slight change in pH when soda loses its fizz?
I did an experiment for my chemistry class and did a control with sparkling water and the pH increased by a significant amount, but when done with sodas like cream soda, coke, or 7 Up, the pH change ...
