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).
2,868
questions
2
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Why do diluted sulfuric acid and hydrogen peroxide etch copper only when chloride ions are present?
I've mixed 30ml 10% sulfuric acid with 20ml 3% hydrogen peroxide and put a drop of this solution onto copper foil. The solution quickly removed the oxide layer from the copper but did not dissolve it ...
1
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0answers
30 views
Pcb etching safety questions (HCl, H2O2, H3PO3)
I am about to embark on a pcb etching journey, however, I am not sure what safety precautions I should take when handling the products. I know that the reagents should be stored in their original, ...
0
votes
0answers
23 views
When base is added to water it produce OH- ions but why does it not react with H2O as when acid is added to water H+ ions forms H3O+ ions? [duplicate]
Why bases produce OH- ions and why this ions Doesn't react with H2O ? Is these ions are stable ? In the case when acid is added it releases H+ ions which then reacts with water to form hydronium ion ...
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1answer
67 views
Can 5% sulfuric acid and 3% hydrogen peroxide form piranha solution?
I'd like to use 5% sulfuric acid and 3% hydrogen peroxide as an etching solution for copper. (In the past I've used dilute hydrochloric acid and hydrogen peroxide but the generation of chlorine gas ...
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0answers
19 views
Do acid/bases leave liquid traces and/or transfer between objects? [closed]
I’m wondering if say someone touches a acid for example HCL and then goes to touch a doorknob or something will the acid be on the doorknob? I am asking his because let’s say someone else opens the ...
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votes
2answers
84 views
How baking soda help in indigestion of stomach? [closed]
We have learnt that baking soda can be used for neutralizing excessive acid in stomach formed during indigestion.
And after some time we get a burp(CO2) after drinking baking soda solution.
So why we ...
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0answers
18 views
Weak Acid/Base Equilibria Forward and Reverse Hydrolysis
Given a weak acid or base equilibria, like $$\ce{NH3 + H2O <=> NH4+ + OH-}$$
Wouldn't it also be possible for the hydrolysis reaction of the conjugate to occur ? $$\ce{NH4+ + H2O <=> NH3 + ...
-1
votes
0answers
27 views
Reaction of CO2 with NaOH and H2O [duplicate]
Sir, I want to know the conditions in which the following reactions takes place.
CO2 + NaOH ---> H2CO3 ---> Na2CO3 (salt of Oxo-acid)
CO2 + H2O ---> H2CO3 (oxo-acid)
So, Both the ...
0
votes
1answer
46 views
Problem understanding the rate of reaction of reversible reactions
Case 1:
$$\ce{CH_3COOH + NaOH<=>CH_3COONa + H_2O}$$
At equilibrium, there remain extremely small concentrations of the reactants (acetic acid and sodium hydroxide), and comparatively large ...
1
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1answer
48 views
Limescale passivation by citric acid?
Cleaning products producers advise against using "home remedies" instead of their products. This advice against using citric acid to remove limescale was especially surprising for me:
...
3
votes
1answer
80 views
Reaction between hydrobromic acid and sodium borate
Write the reaction for a a sodium borate solution being titrated by hydrobromic acid, assuming sodium borate is represented by $\ce{Na3BO3(aq)}$.
I think this is a simple double replacement reaction:
...
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votes
1answer
38 views
Is my understanding of conjugate acid-base pairs correct? [closed]
$$\ce{HCl_{(aq)} + H_2O_{(l)}<=>H_3O^{+}_{(aq)} +Cl^{-}_{(aq)}}$$
Cl- is the conjugate base of HCl. Now, can I say that HCl is the conjugate acid of Cl-?
0
votes
1answer
38 views
Does changes in pH affects cyclic form of glucose in water solution?
Glucose in water solution is mainly in cyclic form. Both base and acid can catalize formation of hemiacetal, but in distinct mechanisms. I found information that monosacharides eg. glucose exist ...
0
votes
1answer
57 views
What are the resulting conjugate acid and base of phenol and 4-nitrophenol
I have to complete the equation
4-nitrophenol + phenol --->
and then label the acid, the base, the conjugate acid and the conjugate base.
I think the answer ...
1
vote
1answer
67 views
Does fluoroantimonic acid dissolve noble metals?
Hello,Does fluoroantimonic acid dissolve noble metals? Nernst equation suggests that platinum would require pH ≈ −20.1 to be dissolved, using Hammett acidity function as an extension of pH ...
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votes
0answers
48 views
How can one measure instantaneous ionisation ratio of a weak electrolyte? [closed]
Trying to get information about ionization ratio of weak electrolyte, led me to a few page with information about how to calculate it, but this will give me a static equilibrium answer. I'd like to ...
-1
votes
0answers
23 views
Why does nitric acid react with less reactive metals [duplicate]
So we are studying the acid base chapter and I came across these reaction:
$$\ce{3Ag + 4HNO3 -> 3AgNO3 + NO + 2H2O}$$
My question is, how can $\ce{Ag}$ react with $\ce{HNO3}$ as it is lower than ...
-1
votes
1answer
20 views
Will concentration of sodium hydroxide affect the result of chicken feather hydrolyzate if i don't standardized it?
The title of the paper:
Isolation and characterization of keratin from chicken feathers https://doi.org/10.1063/5.0002792
Here is the method:
Keratin was isolated by dissolving 5g of chicken feather ...
3
votes
0answers
100 views
Why do we assume that the successive deprotonation of a polyprotic acid happens when only the previous deprotonation has reached equilibrium?
The steps for finding the concentration of the species at the equilibrium of polyprotic acid are as given in this book in section $10.16$ and illustrated on the next page. I have three questions, but ...
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votes
0answers
36 views
Can PTFE (polytetrafluoroethylene) or Teflon™ withstand Sodium Hydroxide and other Super-bases (the opposite of acid)? [duplicate]
I know Teflon can resist strong acids but I'm not so sure about strong bases... Can someone enlight me up?
1
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1answer
65 views
Order of basicity for arylamines and ammonia in gas phase
In aqueous solution, the basicity order is: $\ce{NH3 > Ph-NH2 > Ph-NH-Ph > (Ph)3N}$
What will be the order in gas phase?
Following are some considerations:
1- In $\ce{NH3}$, $\ce{N}$ is $\ce{...
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votes
1answer
55 views
How high does the base dissociation constant, Kb, have to be for a base to be considered "strong"?
I'm just confused as to how high the Kb constant / how low the Ka constant needs to be for a base to be considered a "strong base." The conjugate base of hydrogen phosphate ion, phosphate ...
18
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2answers
2k views
Why is carbonic acid often ignored?
Water (distilled or not) picks up CO2 from the atmosphere, some of which dissolves to form carbonic acid (H2CO3), lowering the pH by a point or two.
From that it seems like carbonic acid would be the ...
0
votes
0answers
32 views
Acidity and structure of EDTA at different pH
I was conducting complexometric titrations to measure the concentration of magnesium ions in my solution.
But of course, as EDTA is a chelating agent, knowing it’s structure and ionization form at ...
0
votes
2answers
62 views
How can one determine the acidic and basic strengths of various substances? [closed]
(a) household ammonia (b) tomatoes (c) Blood (d) Water
For each of the substances (a) through (d) indicate if it is a strong or
weak acid or base, or neutral.
My solution
a): Household ammonia can be ...
0
votes
0answers
29 views
How is MgSO4 a neutral salt? [duplicate]
So the reaction for forming MgSO4 involves two reactants: H2SO4 and Mg(OH)2,
However, the salt formed is netural. Even though H2SO4 is a strong acid and Mg(OH)2 is not a strong base. Shouldn't the ...
1
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0answers
38 views
Is the azo group basic?
I know that amino groups (nitrogen with single bonds with hydrogen and/or carbon) are basic.
I wanted to know if azo groups ($\ce{R-N=N-R}$) are similarly basic.
I searched online but couldn't find ...
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0answers
50 views
How do I know if a compound is an acid, base or salt? [duplicate]
I have been trying to learn how to tell if a compound is an acid, base or salt. Can anyone help me please? Also, is sugar an acid, base or salt?
1
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1answer
128 views
Can ferrous ions exist in an acidic solution?
Can Fe2+ ions exist in an acidic solution or will they always pick up available protons and become Fe3+? My hunch is they can't exist but I'm not really sure.
If the latter, does that mean that ...
1
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0answers
22 views
BTX nitration work-up
I'm trying to understand washing step in a btx nitration process. In all these processes the work-up streams are very similar. The reaction mixture passes from the nitrator to a separator or ...
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0answers
27 views
Best method of electroplating copper onto brass
I need to electroplate a layer of copper onto an irregular brass object (its like a cube). The wikipedia page on copper electroplating states that in order to get a smooth plating I need to add ...
0
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1answer
53 views
How would a low concentrated acetic acid react with highly concentrated KOH solution of equal volume?
If there are two solutions of 25mL volume and one contains 0.5M acetic acid and the other 1M KOH, then will every molecule of acetic acid convert into potassium acetate?
I know acetic acid is a weak ...
-3
votes
1answer
50 views
Why do we need Equilibrium Constant as well as Acid Disocciation Constant? [closed]
I did the experiment to find out the dissociation constant of a weak acid using Henderson equation. However, after going through the theoretical part of the experiment, I am wondering why we need two ...
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0answers
29 views
Acid-Base Reaction with Sunitinib
In a recent lecture discussing the acidity of pharmaceuticals, the acid-base reaction with Sunitinib and NaOH was mentioned. I tried to imagine how this reaction would take place because there are ...
0
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0answers
21 views
Regarding the behaviour and ka kb values of amphiprotic species
Consider the amphiprotic species ${\text{HCO}_3}^{2-}$, and it's predominately a base with K$_b$ of about $2.4 \times 10^{-8}$. Now my question is, can we find the K$_b$ based solely off the K$_a$ ...
0
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2answers
60 views
What might cause overestimated measured pH value of sodium hydroxide solution pumped with carbon dioxide?
I tried an experiment at home where I had a $\ce{CO2}$ tank pumping $\ce{CO2}$ into a solution of $\pu{28 g}$ sodium hydroxide in $\pu{200 ml}$ water. The initial $\mathrm{pH}$ was $11.24.$
I expected ...
1
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2answers
108 views
Effect of H+ concentration on equilibria
Considering the two equilibriums below, when the $[\ce{H+}]$ decreases, my book says that equilibrium \eqref{rxn:2} will shift to the left by a greater extent compared to equilibrium \eqref{rxn:1} ...
12
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1answer
1k views
Why measure both alkalinity and pH in pools if pH alone tells us how acidic or basic something is?
I am trying to better understand the chemistry of maintaining my pool so that I can use the least amount of chemicals to control algae growth and I'm confused by the need to measure both total ...
0
votes
1answer
33 views
Why is sodium carbonate a diacidic base? [closed]
We know,the acidity of bases is defined by the number of replaceable $\ce{OH-}$ ions,or in case of oxides,it is the number of moles of $\ce{HCl}$ it reacts completely. But we know $\ce{Na2CO3}$ is ...
1
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1answer
44 views
Understanding weak acid-strong base titration
Today I stumbled across a website which defined the titration of weak acid and strong base as the following:
"The titration of a weak acid with a strong base involves the direct transfer of ...
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votes
1answer
40 views
Why Na2CO3 is conjugate base [closed]
The defintion of conjugate base is the base formed by removing 1 proton from acid. For example if $\ce{H2SO4}$ is acid then it dissociates as $\ce{H+ + HSO4-}$.
Now we consider $\ce{NaHCO3}$. If we ...
2
votes
2answers
120 views
Efficacy of Intramolecular Friedel-Crafts reaction on =o, c=o bonds of ring structures?
Updated Q:
Inquiring to understand the efficacy of intramolecular Friedel-Craft like reaction on stability on the ring structures with =o, c=o bonds.
Keen to know if ring structures are challenged
...
3
votes
2answers
69 views
Acidic strength comparison of squaric acid and rhodizonic acid
These two are dibasic acids with the following structures (squaric acid and rhodizonic acid in order).
Empirical evidence proves that squaric acid is more acidic than rhodizonic acid.
It is a ...
1
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0answers
27 views
How strongly affected is the buffering capacity of sodium carbonate - sodium bicarbonate by temperature changes?
I would like to do a lab regarding the affects of temperature on the buffering capacity of sodium carbonate - sodium bicarbonate in particular for sulfuric acid. Currently I have two competing ...
4
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0answers
16 views
The role of 2-nitrophenol in tin etchant (aqueous mixture of 2-nitrophenol and NaOH)
Aqueous mixture of 2-nitrophenol and NaOH is a time-honored etchant that dissolves tin-rich alloy and retain the intermetallic compounds from the tin. I wonder the role of 2-nitrophenol in the etching ...
0
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0answers
36 views
Which reaction is happening in the preparation of sulfuric acid through contact process?
I've read that in the preparation of $\ce{H2SO4}$ through the Contact process, on the absortion tower, the gas $\ce{SO3}$ is getting in contact with $\ce{H2SO4} (l)$ , because adding $\ce{SO3}$ to $\...
0
votes
1answer
27 views
Approximation for pH calculation with diluted acids in weak-strong titration curve
I was wondering how one could calculate small pH changes in titrations with dilute acids.
As we know, usually we approximate the pH by saying that the conversion is quantitative. For example, when we ...
-1
votes
1answer
45 views
Why do a stronger acid lose a proton easily when the electromagnetic force in a polar compound should keep it together?
In acid-base theory I've just learned that the stronger the electronegativity, the stronger the acid will be at least it will have an impact on the strength of the acid.
If that so, then the acid ...
1
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0answers
36 views
Function describing pH vs. volume of base used in titration [duplicate]
Sketch a graph of $\mathrm{pH}$ vs. volume when $\pu{50.0 cm^3}$ of $\pu{1 M}$ $\ce{HCl}$ is titrated with $\pu{1 M}$ $x\,\pu{cm^3}$ $(x \in (0,50))$ of $\ce{NH3}.$
As $\ce{HCl}$ fully dissociates, I ...
-1
votes
1answer
53 views
Fundamentally, what is the difference between redox and acid-base reactions?
For example, consider:
$$\ce{NH3 + H2O -> NH4+ + OH-}$$
Here, the $\ce{NH3}$ is acting as a base (By Lewis theory, it is an electron pair donor).
Why don't we consider this to be a redox (there is ...
