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 is on the other hand a chemical species/ molecular entity having an available ...

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14 views

if we given you a compound ,how to detect it is acid or base or neutral [on hold]

if we give you a compound , how to detect it is acid or base or neutral
3
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1answer
37 views

Calculating pH for titration of weak base with strong acid

Calculate the pH at the equivalence point for the titration of 0.130 M methylamine ($\ce{CH3NH2}$) with 0.130 M $\ce{HCl}$. The Kb of methylamine is ${5.0×10^{–4}}$. So I started with the equation: ...
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0answers
20 views

Strong and weak bases? [duplicate]

I have read that a strong base fully dissociates in aqueous solution to form hydroxide ions, and therefore that strong bases are alkalis. I was wondering if you can have a strong base that is not an ...
0
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0answers
23 views

Preparing a buffer from benzoic acid and sodium benzoate

The question is: "You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.180 M sodium benzoate. How much of each solution should be mixed to prepare ...
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2answers
19 views

Confused about strong/weak dibasic and tribasic acids?

I know that sulfuric acid is considered a strong acid, and the dissociation of its first H+ ion is complete and of its second H+ ion is partial. Phosphoric acid is weak and all three of its H+ ions ...
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2answers
69 views

Why do exam questions specify “dilute acid”?

All of the exams that I've sat so far, and the homework questions I've had, always ask for the reaction between a substance and a dilute acid. Is there a difference in the reaction between a dilute ...
-1
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0answers
30 views

Organic Chemistry - strongest acid [on hold]

Hello Friends of Orgo Chemistry! I found this question in my Organic Chemistry Book. And I tried answering, but for some reason I just cannot figure it out. I even looked into the solutions and I ...
1
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1answer
40 views

Reactions of alkynes and Sodium or soda amide [on hold]

What happens when alkynes react with Sodium or soda amide? Does it liberate hydrogen so does it prove that alkynes are acidic? What happens when But-1-yne and but-2-yne react with Sodium and soda ...
2
votes
1answer
52 views

Weak base titrated with a strong acid

If you have a weak base XOH titrated with a strong monotonic acid, where do you start with that? Would you first have the base react with water and break up and determine how much of it does? Or just ...
2
votes
3answers
47 views

Can you find [SO₃²⁻] with just the two acid dissociation constants Kₐ₁ and Kₐ₂?

Sulfurous acid, $\ce{H2SO3}$, is a diprotic acid. \begin{align} K_{a1} &= 1.6 \cdot 10^{-2}\\ K_{a2} &= 6.4 \cdot 10^{-8}\\ \end{align} Is it possible to find the concentration of ...
3
votes
3answers
831 views

How concentrated can an acid be?

How concentrated can an acid be without it being supersaturated? Is there a certain limit to how concentrated an acid or base can be? When I mean concentration, I mean molarity; so how concentrated ...
0
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1answer
36 views

What happens in an acid and metal reaction where the acid is twice as concentrated and the metal twice as much in quantity?

Experiment A 3cm metal 0.5M acid 5 degrees temperature change Experiment B 6cm metal 1M acid How much would the temperature change be, and how much faster or slower would the reaction take ...
2
votes
1answer
71 views

Why is RS- more basic than RO-?

The basic strength is determined by the ability of an ion or molecule to accept a proton. How do I know whether RSH is more stable than ROH? (R is an alkyl group)
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0answers
17 views

Is propylhexedrine freebase or hcl salt more active when consumed

just wondering which form of this compound is more biologically active? Freebase or salt?
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0answers
8 views

Ph change in buffer solution [closed]

I have a 50 mM Sodium acetate buffer pH 5. How do I calculate how much NaOH that is needed to change the pH to 8?
2
votes
1answer
22 views

What's happening at the beginning of a weak acid titration?

At the beginning of a Weak Acid/Strong Base titration curve there is a sharp decrease in $[\ce{H+}]$ and a sharp increase in pH before the ratio between the weak acid and it's conjugate base becomes ...
1
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0answers
11 views

How can I determine the pH of a solution when I add more analyte after the equivalence point?

In titrating 25 mL of a 0.2 M weak acid, HA, with 0.5 M of a strong base, say NaOH, the equivalence point is reached after 10 mL of base is added. I can calculate the pH by first setting up an ICE ...
-1
votes
1answer
51 views

Why does H₂Se have a bigger Ka2 than H₂Te

Why does $\ce{H2Se}$ have a bigger $K_\text{a2}$ than both $\ce{H2S}$ and $\ce{H2Te}$?
1
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1answer
24 views

Why is only one proton transferred in the reaction between Sulfuric acid and Sodium Chloride

$$NaCl+H_2SO_4 \to NaHSO_4 + HCl$$ The above reaction happens, but why doesn't the following happen? Or does it but only when one of the reactants is in excess? $$2NaCl+H_2SO_4 \to Na_2SO_4 + 2HCl$$ ...
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0answers
23 views

How do you calculate the effect of adding more acid past the neutralization point? [duplicate]

In titrating a weak acid with a strong base, and given the mole values of each component at the endpoint and the pH there, how do you calculate the pH and species' concentrations after adding an ...
-3
votes
0answers
23 views

Calculation of acid and base concentrations [closed]

what are the $[\ce{OH-}]$ and $[\ce{H+}]$ in a $4.0\cdot10^{-3}\,M \ce{HCl}$ solution? What are the $[\ce{OH-}]$ and $[\ce{H+}]$ in a $0.043\,M \ce{KOH}$ solution?
1
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2answers
43 views

How do I write out a chemical reaction?

Consider: So, the reaction of nitric acid with sodium hydroxide and zinc oxide is simple because I know that acid + base = salt + water. Therefore: It makes sense. In the second part for ...
1
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1answer
84 views

Chalcogens' hydrides as acids?

I've noticed that chalcogens never form binary acids, and instead end up like water, with very little acidity. Why is this? Or am I wrong and there's a counterexample, if so please give it.
2
votes
1answer
44 views

How many moles NH₄Cl must be added to NH₃ to create buffer with pH=9?

In my textbook there is the following problem: How many moles of $\ce{NH4Cl}$ must be added to $2.0~\mathrm{L}$ of $0.10~\mathrm{M}$ $\ce{NH3}$ to form a buffer with $pH=9$? Assume the addition ...
0
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0answers
34 views

Determining concentration of phosphate buffer from pH?

I bought a phosphate buffer from Sigma/Fluka (73212-1L) containing potassium dihydrogen phosphate ($KH_2PO_4$) and disodium hydrogen phosphate ($Na_2HPO_4$). It is at pH 8.0 but they do not provide ...
1
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2answers
40 views

How to rationalise the basicity order of phenyldiamine?

Why is the basicity of para- > meta- > Aniline > ortho for Phenyldiamine? ($\mathrm{p}K_a$: ortho-9.53, meta-9.12, para-7.96) I tried deducing it using resonance and inductive effects but got stuck.
2
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0answers
23 views

How to prevent Tin ions from precipitating as Tin(II,IV) Hydroxides

Alright, so Tin ions in most of it's salts have the propensity to form Tin(II,IV) Hydroxides and then precipitating out of aqueous solutions. What can I throw in the solutions to prevent this? Using ...
0
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1answer
49 views

Finding new pH after NaOH added to buffer soln given original pH and concentrations of both components

I have a buffer containing 0.2000 M of the acid HA, and 0.1500 M of it's conjugate base A-, with a pH of 3.35. I need to find the pH after 0.0015 mol of NaOH is added to 0.5000 L of the solution. I ...
4
votes
1answer
120 views

Why is p-methoxyphenol more acidic than p-methylphenol?

Why is p-methoxyphenol more acidic than p-methylphenol? According to me, inductive effect really doesn’t matter at para positions and p-methoxyphenol should be less acidic due to the high mesomeric ...
0
votes
1answer
28 views

Why is Ma*Va=Mb*Vb still valid for weak acids/bases? [duplicate]

I asked my chemistry teacher this today and didn't get an answer. It would seem to me that the equation for determining the morality of the unknown in a titration, MaVa = MbVb, would only work if the ...
0
votes
1answer
31 views

What is the reasoning behind the increasing pKa for organic compounds? [closed]

Arrange the following according to increasing $\mathrm{p}K_a$. Cyclohexanol Phenol Cyclohexane carboxylic acid Please tell me the logic along with the solution. I am confused ...
1
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1answer
56 views

Why do carbon dioxide and sodium hydroxide not form sodium oxide and carbonic acid?

Why do carbon dioxide and sodium hydroxide not form sodium oxide and carbonic acid? $\ce{CO2 + 2NaOH -> Na2O + H2CO3}$ as opposed to: $\ce{CO2 + 2NaOH -> Na2CO3 + H2O}$ This is in the ...
-1
votes
1answer
36 views

How to calculate the pH of a sodium fluoride and hydrogen fluoride aqueous mixture? [closed]

What is the pH of a solution that is $0.20~\mathrm{M}$ in $\ce{HF}$ and $0.40~\mathrm{M}$ in $\ce{NaF}$? $K_a = 7.2\cdot10^{-4}$ I am stumped on this question. Is the concentration greater in ...
2
votes
1answer
23 views

What happens if I have an acid/base equillibrium and remove hydronium ions until there is 50/50 of acid and conjugate base?

Suppose I had an acid HA, and it reaches equilibrium in water. Then I remove the hydronium ions. I don't know how I would do this, maybe adding some hydroxide ions. My question is can I do this and ...
1
vote
1answer
32 views

Including H⁺ from the hydrolization of the acid in a titration pH calculation?

Let's say you are doing a standard titration problem, for example: Find the pH after adding $10~\mathrm{mL}$ of $0.3~\mathrm{M}$ $\ce{NaOH}$ in the titration of $25~\mathrm{mL}$ of ...
1
vote
0answers
42 views

Why is the vertical part of a titration curve longer for a strong acid by a strong base than for a weak?

As the title says, I would like to understand chemically why this occurs. My theory behind it is that in the former case both are completely dissociated, and so at the equivalence point (and ...
0
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0answers
20 views

Methylene Blue Photo-initiation PH

I am working on a project using methylene blue as photo-initiator for a polymerization reaction. In this classic reaction methylene blue will get reduced into leuco-methylene blue in presence of some ...
1
vote
1answer
59 views

Product of Reaction between aluminium chloride and N(CH₃)₃

Does anyone know the product of the reaction between $\ce{AlCl3}$ (aluminium chloride) and $\ce{N(CH3)3}$ (trimethylamine)? Thanks!
2
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0answers
35 views

Separating metals out of a magnet

I have acquired the crushed magnet out of a motor I was given. If I'm correct that the magnet is NdFeB magnet, how could I separate out all the metals into a pure or oxide form? And for hard drive ...
3
votes
1answer
32 views

How to predict the colour of a pH indicator using Le Chatelier's principle

Hi, The question I have is above. Could someone explain why the answer is A? Thankyou, this is greatly appreciated (this is in preparation for an exam, it is not cheating) What I think so far: -Does ...
0
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0answers
31 views

pH Activity much lower than pH Experimental and pH Calculated

Why is the $pH$ using Activity Coefficients significantly lower than calculated and measured $pH$? Here is my work: $\ce{H2PO4- + NaOH <=> HPO4^{2-} + H2O + Na+}$ $pK_{a_2}= 7.2 $ $$\mu ...
3
votes
1answer
43 views

Why does phosphorus tribromide act as a Lewis acid (electron acceptor)?

This question is purely out of curiosity and to help me remember the "why" of a mechanism to help me remember the "what/how". In organic chemistry we recently studied the Sn2 Substitution of Primary ...
3
votes
1answer
25 views

Impossible pH For Aqueous Weak Acid Solution

An aqueous solution of $\ce{HCl}$ has a $\mathrm{pH}$ of $0.00$ if $[\ce{H+}] = 1.00 \; \mathrm{M}$. I tried to see if an aqueous solution of acetic acid could have a $\mathrm{pH}$ of $0.00$, given ...
0
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0answers
67 views

Purity of precipitate in selective precipitation

An aqueous effluent contains 12 M Cd2+ and 10 M Mg2+ as solution of nitrates. Current practice is use NaOH to selectively precipitate the metals. (a) Is it feasible to get 0 Cd impurities in Mg ppt ...
3
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1answer
32 views

Carbonic acid-hydrogencarbonate buffer system pH calculation?

I am learning about the pH of buffer solutions, and am slightly confused by my text book's calculation. For the blood's buffer system of carbonic acid and hydrogencarbonate ions as the conjugate case, ...
0
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1answer
22 views

Acid-base related chemistry [closed]

What is the function of silica, $\ce{SiO2}$ in the equation $$\ce{CaO + SiO2 -> CaSiO3}$$ a) A basic oxide b) A acidic oxide c) A reducing agent d) An oxidising agent Please explain.
3
votes
1answer
49 views

What is the reaction equation for a mixture of trichloroethanoic acid and dimethylpropanoic acid?

Write an equation for the reaction you might expect to take place if trichloroethanoic acid, $\ce{Cl3CCO2H}$, $\mathrm{p}K_a=0.65$, were added to dimethylpropanoic acid, $\ce{(CH3)3CCO2H}$, ...
1
vote
1answer
64 views

How to calculate the volume of a sodium hydroxide solution necessary to add to water, to raise the pH to a certain value?

What volume of 0.300N $\ce{NaOH}$ would be needed to bring $16.0~\mathrm{mL}$ of distilled water that has a pH of 7.00 to a new pH of 12.42? This is my attempt at a solution: $$\ce{NaOH + ...
2
votes
1answer
45 views

Which is More Stable with Boranes: Amines or Phosphines?

Given borane's ($\ce{BH3}$) LUMO, which of these Lewis bases would have a more stabilizing interaction? In acid bases that means the higher HOMO and lower LUMO equals a stronger dative bond I ...
0
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0answers
24 views

Working out the number of Moles adsorbed of Ethanoic acid

I'm currently trying to work out the Freundlich isotherm constants of Ethanoic Acid or Acetic acid. The equation is $$\frac{X}{M}=AC^{(1/n)}$$ with X being number of moles of acid that are adsorbed, ...