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0 votes

How to find out pH of aquarium and apply it when adding HCl?

You are seriously over-thinking it. Get some liquid indicator ( methyl blue ?). Measure the pH. Likely no correction will be needed. Natural waters generally have buffering. When I was a boy in ...
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0 votes

What's the pH of a solution knowing only pKa, mass and volume? (no molecular mass known)

Unfortunately knowing only the pKa, the mass of the acid in the solution and the volume of the entire aqueous mixture it's not enough, one will always end up with an equation with two variables, which ...
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How to find out pH of aquarium and apply it when adding HCl?

If you need to check the pH of your aquarium, you can use pH test paper. Its results can be seen immediately, which is convenient for you to carry out the next step. Sincerely recommend this pH test ...
0 votes

What determines strength of nucleophile--Polarisability or Electron density

Nucleophilicity is a kinetic concept, and differs from basicity which is a thermodynamic concept. There are some molecules which are both strong bases, like the ethoxide anion, and hence some factors, ...
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1 vote

Could neutralisation of safe chemicals produce dangerous ones?

If you're using oxidizing acids (mainly nitric, perchloric, chloric, perbromic, bromic, periodic, iodic, also potentially selenic and arsenic acids and obviously chromic or permanganic acids and ...
0 votes

What determines strength of nucleophile--Polarisability or Electron density

The most correct answer would be that the bromide ion is both a strong nucleophile (since the electrophiles in reactions involving bromide are usually soft) and both a weak base in aqueous solution(...
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Which one is more Bronsted basic?

Yours thoughts seem to be correct. Imidazole pKa is 14.5 and 6.8. Pyrrole pKa is 16.5. You do have a resonance form for the imidazole ring. Additionally, nitrogen is electron withdrawing. The ...
2 votes

Calculating rate constant for reaction between potassium permanganate and oxalic acid

If a reaction is second order in $\ce{A}$ and $\ce{B}$, with $\ce{[A]_0 ≠ [B]_0}$, and with a rate law given by $\pu{d[A]/dt = d[B]/dt = k[A][B]}$, the integrated law is : $$\ce{\frac{1}{[B]_0 - [A]_0}...
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2 votes

Protonation in acid-catalyzed nucleophilic attack of alcohol on carbonyl

I assume OP is wondering why always showing carbonyl carbon protonation instead hydroxyl carbon protonation in the mechanism of Fischer esterification. As I have mentioned this in another answer, ...
4 votes

Safe disposal of hydrochloric acid

You are so lucky as to have found 2 liters of toilet bowl cleaner (concentrated). There used to be a variety in my grocery store that was 20% HCl, but now it is only 10%, so now I have to use twice as ...
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3 votes

Safe disposal of hydrochloric acid

Some of the answers above go into a lot of good detail as to the chemistry behind the answer, but I want to get to the point and avoid extraneous detail. Gradually pour chalk or baking soda into it, ...
0 votes

Protonation in acid-catalyzed nucleophilic attack of alcohol on carbonyl

Your mentioned points are somewhat correct. Look in acidic medium electrophilicity of carbonyl increase, secondly nucleophile(like alcohol) get consume due to protonation. For the reaction to happen ...
11 votes

Safe disposal of hydrochloric acid

Thankfully, 2 liters is not alot. Muriatic acid is used to clean bricks and concrete. A local mason or contractor might happily take it for free. But, if you love a good science experiment, start by ...
7 votes
Accepted

Safe disposal of hydrochloric acid

$1$ liter $\ce{HCl}$ $20$% weighs $1.101$ kg, and contains $0.20 · 1101$ g/($36.45$ g/mol) = $6.041$ mol $\ce{HCl}$. $2$ liters $\ce{HCl}$ $20$%, contain $12.082$ mol $\ce{HCl}$. To neutralize this ...
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8 votes

When NaOH ionizes in water, does the OH– react with the water molecules or with the hydronium ions from the dissociation of water?

Even pure water contains $\ce{H2O, OH- and H3O+}$. The two ions can either react with water, or with each other: $$\ce{OH-(aq) + H2O(l) <=> H2O(l) + OH-(aq)}\tag{1}$$ $$\ce{H3O+(aq) + H2O(l) <...
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1 vote
Accepted

Why is phosphine more acidic than ethylene?

Phosphorus, a third-period element, forms a weaker bond to hydrogen than carbon; see for instance https://chem.libretexts.org/Courses/Valley_City_State_University/Chem_121/Chapter_8%...
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-1 votes
Accepted

Why do stable covalent compounds react with water

What you meant by "stable" is relative. It is not some absolute. First we need to define "stability". From what you wrote, I assume by "stable" you mean compounds that ...
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2 votes
Accepted

Is ethylene more acidic than phosphine?

It seems to be extraordinarily difficult to find a figure for the pKa of a phosphine proton (P-H). However the preparation of alkylsilylphosphines has been reported by nBuLi deprotonation of phosphine ...
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2 votes

Why can't the product of an acid reacting with water react with water itself and produce OH-?

I really like this question because it digs at wanting to understand what's going on beneath the equations you've been given to know why that equation works. Orthocresl answered it really well, but I ...
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8 votes
Accepted

Why can't the product of an acid reacting with water react with water itself and produce OH-?

It definitely does. Let's simplify it to a monoprotic acid (like acetic acid, $\ce{CH3COOH}$), which I'll just represent as $\ce{HA}$ for simplicity. In a solution of the acid, you will have all of ...
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10 votes
Accepted

Predict who is the acid and who is the base in an acid-base reaction using pKa

But this reasoning, in my opinion, does not make much sense, as the $\mathrm{p}K_\mathrm{a}$ of two different reactions are compared: the acid hydrolysis reaction of ammonia, which generates $\ce{NH2-}...
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4 votes

Why is the inductive effect possible?

That's an interesting reasoning you give here. The point is, the inductive effect is not the major factor explaining the acidity of a compound. Electronegativity will give insights on the position of ...
1 vote

What is the pKa Range for weak acids and bases?

What is the pKa Range for weak acids and bases? Bases don't have a $\mathrm{p}K_\mathrm{a}$. To discuss the strength of a base, you can look at the $\mathrm{p}K_\mathrm{a}$ of the conjugate acid, ...
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5 votes
Accepted

Should nitric acid be classified as a strong acid? Does it completely dissociate in water?

We are really splitting hairs here. As described in this answer with respect to bases, whether an acid or base is "strong" or "weak" is not cut and dried because the dissociation ...
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