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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Why is a buffer solution most effective when concentrations of salt and acid are the same?
Why does a buffer work most effectively when the concentration of salt and acid is 1:1?
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Esterification and dehydration synthesis
I know there are many more terms out there like polymerization, condensation, etc. But the important thing is whether they can be differentiated or not.
In Esterification, which I just learned, needs ...
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Inductive effect
In my teacher's power-point states that we must consider that inductive effect in $CH_{3}COOH$ exists because of the electron deficiency in $C$ (partial positive charge $\delta^{+}$) as a result of ...
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Acidity of aldehydes
Which is more acidic between methanal ($\ce{HCHO}$) and ethanal ($\ce{CH3CHO}$).
Please explain using General organic chemistry basic concepts.
My Effort:
I saw the stability of the conjugate base.
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What's the Acid Ionization Constant of the Hydrogen Proton?
What is the $\ce{K_{a}}$ value for $\ce{H^+}$. I understand that the hydrogen proton doesn't stick around in solution by itself for very long. Nonetheless, does it have a $\ce{K_{a}}$ value? Can it ...
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Balancing Redox Equations
I was taught to balance redox equations with acid/base considerations. Instead of arbitrarily adding $\ce{H^+}$ and $\ce{HO^-}$ ions and memorizing separate rules for acidic and basic solutions, I was ...
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Hydrolysis of ammonium cloride
As we all know ammonium chloride is a acid. And what explains this is its salt hydrolysis. It breaks down into ammonium and chloride ions. Ammonium react with water to produce hydronium or hydrogen ...
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Identifying Nucleophiles and Electrophiles
Are all polar molecules both nucleophilic and electrophilic, depending on which atom you are talking about? Take water for example. Oxygen bears the partial negative charge. Oxygen is nucleophilic. ...
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203 views
Strongest B/L Acid Which Can Exist (Leveling Effect)
Got a few issues with this:
Here is the Lewis Structure:
As we can see, we have five lone pairs on which a hydrogen proton can land and form the solvent's conjugate acid. Let's consider them left ...
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Properties of Polyprotic acids?
I have a graph of a titration of a weak polyprotic acid with a strong base.
I graphed $p\ce H$ versus amount of strong base added.
Now since the acid is polyprotic, how do I determine which ...
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What are the factors that affect the corrosiveness of an acid?
Acids are usually corrosive but what determines this? Is it the concentration of the acid or strength of the acid ($K_a$ value)?
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Thymolphthalein solubility
I already know that thymolphthalein is soluble in alcohols, very alkaline aqueous solutions, acetone, and propylene glycol methyl ether. My questions are what other solvents dissolve thymolphthalein, ...
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Predicting the pH of a weak acid and weak base solution
I know that it is possible to predict whether combinations of acids and bases will be acidic, basic, or neutral:
weak acid (WA) and strong base (SB) reacts basic
strong acid (SA) and and weak base (...
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Explain why the acidification of solution can lead to separation of ions such as Fe2+ and Zn2+ from aq solution
Given the $K_{sp}(\ce{ZnS})= 2.5\cdot10^{-22}$ and the $K_{sp}(\ce{FeS})= 3.7\cdot10^{-19}$, why would $\ce{Fe^{2+}}$ ions remain in the solution but not $\ce{Zn^{2+}}$ with the acidification of the ...
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Carbon dioxide in lime ground
Is storing carbon dioxide in limestone a good idea? Wouldn't that lead to a reaction like
$\mathrm{C}\mathrm{O}_2 + \mathrm{H}_2\mathrm{O}\to {\mathrm{C}\mathrm{O}_3}^{-2} + 2\mathrm{H}^+$
And then ...
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How can you tell how much actually reacted in an acid base reaction
If you facilitate a weak acid base reaction. i.e. $\ce{NaOH + H2SO4}$. All of it may not react and the solutions will not neutralize. How can you determine how much actually reacted?
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Anthocyanins as pH-indicators: stop the titration at red, purple or blue?
If you titrate some hydrogen bromide solution (0.1 M) to some sodium hydroxide in order to determine the exact concentration of hydrogen bromide (0.1 M), and you use anthocyanins as a pH indicator. ...
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How do you calculate the total heat capacity of a reaction
I need help with this one homework question:
I am combining $100\,\text{mL}$ of $0.5~\text{M}~\ce{HCl}$ and $100~\text{mL}$ of $0.5~\text{M}~\ce{NaOH}$ to obtain $200~\text{mL}$ of $0.25~\text{M}~\...
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Conjugate acids and bases
Consider the reaction
$\ce{NH3 + H2O -> NH4+ + OH-}$
Here, $\ce{NH3}$ is a weak base, and thus $\ce{H2O}$ becomes a weak acid. Thus, shouldn't its conjugate be a strong acid? However, $\ce{NH4+}$ ...
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How to determine the reaction of a strong electrolyte? [closed]
I'm told the $\ce{KMnO4}$ is a strong electrolyte.
How can I figure out how the reaction looks like?
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Is acetate a weak base due to its resonance structure?
I just read that acetic acid is an exception to the general idea that the conjugate base to a weak acid is a strong base. The example says that the conjugate base of a weak acid will only be strong ...
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The significance of the dissociation constant of an indicator
In the chapter acid-base, I learned about indicators and how they are actually weak acids.
This is the equation given in our book:
$\ce{HIn + H_2O <=> H_3O^+ + In^-}$
$K_{in}= \left(\frac{[\...
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Figuring out the concentration of weak polyprotic acids in presence of strong acid
We have a $\rm{0.1 \ M}$ solution of $\rm{H_2S}$ with a $\rm{0.1 \ M}$ solution of $\rm{HCl}$. We need to figure out the concentration of $\rm{S^{2-}}$ ions at equilibrium.
$$\rm{H_2S \...
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Calculating approximate pH of polyprotic acids
When I took up ionic equilibria and titrations after a long break, I found it hard to solve the questions regarding pH calculations of polyprotic acds. Consider these two questions as examples:-
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How does iron rust in basic conditions?
I performed an experiment about the corrosion of iron. I used acid and base in the experiment.
I understand that the acid speeds up the corrosion of iron. But I don't understand why the base also ...
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Buffers calculating amounts of acid & base
Quick run down, I was given pH of buffer 4.5 and then pKa of acid 4.79
I then had to work out volume of acid and volume of base using $\text{pH=pKa}+\log_{10}{\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)}...
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Corrosion of Aluminum by Baking soda
An aqueous solution of sodium hydrogen carbonate corrodes aluminum foil quite readily. How do you explain this?
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What are the properties of various solutions at pH <2 that may cause injuries?
For example, why do some solutions not cause any injuries at pH 2 while HCl does?
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Perfluorobutanesulfonic acid (PFBS) Safety and Toxicity
I was wondering if anyone had any experience with PFBS or PFOS (perflurooctane sulfonic acid)?
I am thinking about trying to purchase some of these fluorosurfactants in bulk in order to (hopefully) ...
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Calculating the pH of a solution of Ca(OH)2
A solution prepared by dissolving $2.8 g$ of lime, $\ce{CaO}$ in enough water to make $1.00 l$ of lime water ($\ce{Ca(OH)_{2(aq)}}$). If solubility of $\ce{Ca(OH)2}$ in water is $1.48 g$. The $p\ce H$ ...
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How to Understand Concentrations Measurement
I was helping out in my beginner's chemistry class today, as I'm a "lab assistant" of sorts, and was reading on a bottle of HCl: 1M. I'm assuming that is the concentration of how much hydrocloric acid ...
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How to estimate pH?
How you you calculate/estimate the pH of a solution with 3 components all of different pHs?
Is there a paper describing this?
For example:
0.1M Buffer PCTP at pH 9.5
1.6M Sodium Dihydrogen Phosphate ...
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1answer
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Food safe basic polyelectrolytes?
Pectin is an example of a food safe polyelectrolyte. It acts as an acid because it is a proton donor and develops negative charges along the polymer.
Can you think of any examples of food safe ...
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Acetic acid freezing distilation
How can acetic acid be distilled by freezing when its freezing point is above the freezing point of water.
Examples on the web show the water portion of the vinegar as ice and the acid as a liquid ...
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What's the technical term for supercharging an acid with an oxidizer? And does it always work?
In a recent Mythbusters episode, where they tested some Breaking Bad chemistry assertions, they debunked the hydrofluoric acid body-dissolving myth referenced elsewhere in Chemistry.SE in the question ...
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Impact of detergent on internal living tissue?
There was some spirited debate between the members of my chemistry lab today about the theoretical consequences of ingesting a large amount of the detergent Triton X-100 at a 100% concentration. The ...
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Why is methyl group more electron-donating than tert-butyl group?
As title says, why is methyl group more electron-donating than tert-butyl group? The context behind this is stabilization of conjugate base. (http://www.khanacademy.org/science/organic-chemistry/...
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Effect of dillution on titration
When we are titrating acid/base using ph meter we add distilled water to immerse the ph electrode.
Won't this affect the concentration of the acid/base: I mean isn't this dillution.
Won't this ...
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On the scale of stuff with a pH
I am a confused (and somewhat anal retentive) non-chemist who is trying to understand what pH is. I have come to understand it is a measure of acidity, but I have not yet figured out what that means ...
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Chemical reasons for choosing Salt Water or Chlorinated pool?
I am currently researching as too which is better for maintaining the chemical balance in a swimming pool. I have obviously tried the standard Google search for ...
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Why are the majority of cleaning solutions basic?
When testing for pH for common household cleaning products, such as dishwasher fluid, I noticed that majority of them tend to be basic? Why is that? Do acid make good cleaning solutions as well?
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How can one find products when one knows the reagents?
I'm going to use an example (I could have used a different one);
On the document it is about the study of the chemical balance of an acid-basic solution.
The chemists have written the chemical ...
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How can I find pKa from a titration curve?
I am fully aware that the pKa is the pH at half the equivalence point, but are there some programs or methods I could use to accurately estimate the pKa without manually drawing lines on the graph?
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How would I neutralize a PEP (Phosphoenolpyruvic) acid?
PEP (Phosphoenolpyruvic acid) is acidic but I need to make it neutral. I need a solution (pH 6-8) of PEP in a final 1 mL volume with a concentration of 100 mM.
How would I make this?
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Understanding the rate of change in titration curves
As I am looking at titration curves, a few things stand out. For now, I have a two part question:
When titrating an acid with a base, for instance, the pH rises more or less abruptly around the ...
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Pipetting strong acid with plastic material
Can I pipette concentrated sulfuric acid using a plastic pipette tip? Will either the plastic or the acid be affected?
