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).
2,423
questions
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0answers
13 views
What happens to the concentration of H3O+ ions on diluting an acid? [closed]
Look above for the question. And please support with a reason.
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0answers
21 views
Does Magnesium metal react with carbonic acid?
I use rainwater in my house for my water supply. I collect the water in plastic lined tanks. Some of my piping at home is copper, and I have blue stains in my shower, because I think the copper from ...
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0answers
30 views
Is diphosphorus tetraiodide an acid? [closed]
i am working on the use of acid as a catalyst on a particular reaction condition, i am not sure whether i can also use diphosphorus tetraiodide (P2I4) as an acid catalyst.
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0answers
24 views
Concentration of HCl & H3PO4 in a solution [closed]
A solution of HCl & H3PO4 has an unknown concentration. I need to calculate the concentration of HCl & H3PO4 concentration of the solution.
To do this, I pipette 5mL of the solution into a ...
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3answers
66 views
Converting Lactic Acid to Potassium Lactate
I am looking to try an experiment incorporating potassium lactate into soap making. This seems to be new territory for soap makers in that sodium lactate is usually used. I found a bottle of "Lactic ...
0
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0answers
37 views
How can sodium chloride solution be alkalising? [closed]
I'm reading a book on dental care just now, and the author claims that rinsing one's mouth with salt (sodium chloride) in water will "alkalize" the mouth.
Isn't a salt-water solution neutral?
Why ...
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0answers
37 views
Why is acid particularly dangerous? [closed]
Why is it bad to dip my hand in a solution with many H+ ions (an acid) as opposed with many Na+ ions (like saltwater)?
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0answers
51 views
Why can't strong bases cleave ethers?
I'm imagining a strong base like NaNH2 attacking the adjacent carbon of the ether, giving the oxygen a lone pair and forming an alkoxide. NH3 has a pKa of 36 while an alcohols (conjugate acid of ...
1
vote
2answers
48 views
What is the difference between Half Equivalence point and Equivalence point?
OKay I learned in class that equivalence point is the time of neutralization, where the # of moles of acids and base present is in equivalence/same amount.
Now I was also told that Half equivalence ...
0
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4answers
95 views
If sulphuric acid barely evaporates, why we can smell it? [closed]
If sulfuric acid barely evaporates, why we can smell it? Or does it give off sulfur dioxide gas?
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0answers
47 views
Weak Acid Weak Base Neutralization Mechanism
According to the bronsted-lowry definitions of acids and bases, an acid is an H+ donor, while a base is an H+ acceptor. However, in my introductory chemistry class, my teacher did not explain this ...
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0answers
36 views
How identify acid and base for Henderson-Hasselbach equation [closed]
If I am asked to determine the pH in e.g.
60 mM Na2CO3 and 30 mM NaHCO3
or 50 mM NaHSO4 and 40 mM Na2SO4
How do I go about to identify which of these two is the base and which is the acid?
...
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2answers
86 views
What is the oxidation state of Boron in Ammonia Borane? [closed]
So I was searching about the difference between redox reactions and Lewis Acid-Base reactions and came across classical example of latter,
$$\ce{NH3 + BH3 \rightarrow NH3BH3}$$
Now in this example ...
1
vote
2answers
95 views
Strength of weak acids and bases: Is methane better base than ammonia? [closed]
$\mathrm{p}K_\mathrm{a}$ of methane is $\sim 50$ and that of ammonia is $\sim 37,$ thus ammonia is a better acid than methane, which implies methane is a better base than ammonia.
But I don't see how:...
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0answers
39 views
Why does body soaps produce more foam than Hair Shampoo? [closed]
Body Soap and Hair shampoo are both cleaning agents in our daily life.
Why does body soaps produce more foam than Hair Shampoo?
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1answer
38 views
Why does a strong base completely neutralize a weak acid? [closed]
For the longest time, weak acid-strong base titration curves completely baffled me. I understood that the equivalence point of a strong acid-strong base titration is reached when equal numbers of ...
0
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0answers
35 views
Why is H2Te the strongest acid among the following?
Among H2S, H2Se, H2Te the strongest acid is H2Te. The reason being that the bond strength in it the weakest so it dissociates easily.
But my question is that why does it looses H+ in first place ...
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0answers
32 views
How is HCl relevant in the reaction of iodomethane and ammonia? [closed]
The following reaction is conducted using $\pu{1.8 g}$ of $\ce{CH3I}$ and $\pu{250 mL}$ of a $\pu{0.2 mol L-1}$ solution of aqueous $\ce{HCl}$.
$$\ce{CH3I (l) + NH3 (aq) -> CH3NH2 (aq) + HI (aq)}$...
1
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1answer
30 views
How to determine the pH of citrate buffer system
I used this table (http://microscopy.berkeley.edu/Resources/instruction/buffers.html) to make a citrate buffer system. The Pka value is 6.4, and I multiplied the solution by ten to make a larger batch....
5
votes
3answers
409 views
Am I understanding buffering capacity against strong acid/base correctly?
I just want to make sure I'm understanding buffering capacity correctly.
I've been working on this problem:
Suppose you have an acetic acid buffer, $\mathrm{p}K_\mathrm{a} = 4.74$, at the ...
0
votes
2answers
51 views
Acidic strength comparison between sulphuric acid and nitric acid
Why is $\ce{H_2SO_4}$ more acidic than $\ce{HNO_3}$. Shouldn't it be the other way around because $\ce{N}$ is more electronegative than $\ce{S}$?
My reason: $\ce{O}$ can take electrons more easily ...
0
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0answers
21 views
How do you find the ph of lime juice through titration?
I am doing an experiment on the effect of time on the pH of Lime juice.
I was wondering how you would calculate the pH through titrations using 1 Molar NaOH. I have been racking my brain on this for a ...
0
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0answers
31 views
Trends in the acid strength of oxoacids
I was working on a problem regarding the relative acidity of oxoacids in the form $\ce{HYO3}$ where $\ce{Y}$ represents a group 17 element.
The question (which is from a worksheet created by a ...
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votes
2answers
52 views
How are CH3COOH molecules ionisied into H+ and CH3OO- [closed]
It's written in my chemistry book ,under weak acids, that the molecules of organic acids are partially ionised in water into ions. But I don't understand how molecules are ionised.
I'm an ol ...
1
vote
2answers
83 views
Why is H⁺ ion considered the source of acidity, and OH⁻ considered the source of basicity? [closed]
As the title implies, what caused the association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and basicity?
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votes
2answers
103 views
Gold refining using HCl
I am trying to dissolve base metals off of gold plated electronic scrap, and I am using HCl to dissolve some of the base metals.
I pored in the HCl into a flask containing the scrap ( the contents of ...
0
votes
2answers
39 views
How can I eliminate the harmful gas produced from the heating/manipulation of galvanized steel? [closed]
When welding on steel with a galvanized coating, hexavalent chromium is yielded from the chemical reaction. This gas is something that I would like to eliminate before I begin welding, possibly with ...
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votes
1answer
44 views
How to tell if an acid disassociate completely or partially? [closed]
what is the difference between
and
how can I tell which one is the stronger acid, base on the 2 equations?
0
votes
1answer
30 views
Why does Calcium (specifically Calcium Carbonate) inhibit the Citrate buffer system?
Is it because citrate chelates calcium and then is unable to react with other chemicals being added? If so can someone explain this reaction to me, or if not provide what the reason is? If anyone has ...
0
votes
1answer
31 views
What happens to concrete if you add lye to the mix?
What happens if you’re mixing concrete and you add some lye to it? Does it make it weaker, stronger or does nothing at all? I’m guessing concrete is basic so adding lye to it might expedite the ...
3
votes
1answer
55 views
Accurate method to calculate the pH of a salt from a weak acid and weak base
Can someone help me with this?
The problem is as follows:
Find the $\mathrm{pH}$ of $\pu{1M}$ solution of $\ce{NH4CN}$. Their respective
hydrolysis constants are:
$K_h = 5.6\times 10^{-10}$
...
1
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0answers
39 views
Why H3PO2 does not form acid salt? [closed]
Why $\ce{H3PO2}$ does not form an acid salt? I didn't understand the language.
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votes
1answer
38 views
Which is more basic among N-ethylpiperidin and 1-azabicyclooctane?
Shouldn't A be more basic than A because in B the conjugate base formed in B is more unstable as compared to A and because a bridge head nitrogen is formed In B which is comparatively unstable than ...
0
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0answers
29 views
Reference for Hammett acidities of dilute H2SO4?
When $\ce{H2SO4}$ is dissolved in water in little amounts ($<\pu{1M}$), the $\mathrm{pH}$ scale can be used to measure the acidity of the solution. However, in larger concentrations, this breaks ...
0
votes
1answer
38 views
Contradictions in acidity and solubility of phenol derivatives
o-Nitrophenol is less acidic in comparison to p-nitrophenol due to intramolecular hydrogen bonding. This effect also is the reason for o-nitrophenol being less soluble in water.
At the same time, ...
1
vote
2answers
119 views
Deprotonated form of phenolphthalein
The wikipedia page states clearly that the coloured form of phenolphthalein is the one with two protons removed. What is the evidence that phenolphthalein loses both protons in basic solution? And ...
1
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0answers
19 views
How are the pKa's of very strong acids derived mathematically?
It is often said that "for very strong acids (HCl, H2SO4, etc.), the pKa value cannot be experimentally derived from standard titration and instead needs to be theoretically computed". However, I ...
0
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1answer
48 views
Estimation of Sodium Hydroxide
Why is estimation of sodium hydroxide more accurate with oxalic acid rather than with sulfuric acid or any other strong acid?
0
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0answers
22 views
How ion size/electronegativity influences strength of an acid
My prof was explaining how we can use the structure of acids and bases to rationalize relative strengths (ie: acid X is stronger than acid Y because ...). He then went on to explain how when ...
4
votes
1answer
49 views
Understanding sodium hydroxide drain cleaner's exothermic dissolution of aluminum; does the aluminum need to be oxidized before it dissolves?
I'm not a chemist but I remember that the standard HF/nitric silicon etch used in micro-fabrication supposedly worked in two steps; the HF would dissolve the thin SiO2 oxide layer on the silicon ...
0
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1answer
67 views
Validity of the leveling effect of water in nitration reactions
Wikipedia gives this as the levelling effect of water
Any acid that is stronger than $\ce{H3O+}$ reacts with $\ce{H2O}$ to form $\ce{H3O+}$. Therefore, no acid stronger than $\ce{H3O+}$ exists in $\...
1
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1answer
153 views
Do amphoteric cations exist?
I know that anions such as $\ce{CH3COO-}, \ce{OH-}, \ce{CN-}$ are basic in nature, since they are conjugate bases of weak acids. Similarly, cations such as $\ce{NH4+}, \ce{H3O+}$ are acidic in nature ,...
0
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2answers
241 views
Which one is the strongest base among the following compounds?
I am confused between option (2) and (4). Both lone pairs of nitrogen are localized, so next, I looked at the hybridization of $\ce{N}$ in each compound. As in (2), the $\ce{N}$ is $\mathrm{sp^2}$ ...
16
votes
1answer
3k views
Neutralizing a sulfuric acid spill
From my AP Chem Prep Book:
What should you do if you spill sulfuric acid on the countertop?
A) Neutralize the acid with vinegar.
B) Sprinkle solid NaOH on the spill.
C) Neutralize the acid ...
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votes
1answer
103 views
Lewis acidity comparison of boron and aluminium trichlorides
Lewis acidity is a function of electron deficiency on the acceptor atom, which in this case is $\ce{B}$ and $\ce{Al}$ respectively.
Back donation is better as is the case of $\ce{B}$, due to better ...
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votes
3answers
36 views
Is acidic character related to reducing power?
My book says that the acidic character of halogen acids increases on going down the group because the bond strength decreases, making it easier to release the $\ce{H+}$.
But I also know that $\ce{HI}$...
3
votes
1answer
56 views
Why is high molar molar mass a requirement of good primary standards for volumetric analysis? [closed]
I have been taught that using primary standards with a relatively high molar mass will reduce the error between the equivalence point and the end point during titration. However, I am unsure as to why ...
0
votes
0answers
15 views
measuring the pKa of acetic acid in mixtures of water and methanol(changing percentage)
My goal is to measure the pKa of acetic acid in different mixtures of water and methanol, in which the proportion by weight of methanol will be changed. How can I measure the pH of this solution? Is ...
0
votes
1answer
46 views
Finding Ka of a monoprotic weak acid from pH and concentration of added sodium salt
A solution of $\pu{0.36 M}$ of the sodium salt of a generic monoprotic weak acid $\ce{HA}$ has a $\mathrm{pH}$ value of $8.782.$ $K_\mathrm{a} = ?$
Why doesn't the following formula work in this ...
7
votes
2answers
398 views
How does ammonium chloride increase the solubility of magnesium hydroxide in water?
In my textbook it is written that $\ce{Mg(OH)2}$ is slightly soluble in water, and it forms a milky solution which is called "milk of magnesia".
Its solubility can be increased by the addition of $\...
