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# Tag Info

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If the $n$-factor is what I assume it is (the basicity, or ‘how many moles of sodium hydroxide can one mole of acid neutralise?’) then … It is really hard to explain this without molecular structures. Sum formula are of little help to chemists once you reach more than four or five atoms or if there are two types of non-hydrogen atoms. Two compounds may have ...

0

I am afraid the answer if your teacher or textbook has told that the n-factor of phosphoric acid is 2, they are teaching it the wrong way. The concept of equivalent weight is totally dependent on how the reaction equation is written, therefore there is no fixed equivalent weight. Think of the permanganate ion- how many equivalent weights does it have! I ...

1

$n$-Factor is basically a method to find out a relationship between the compound and what it is equivalent to in terms of acidic nature or basic nature. Note that the two hydrogen atoms in $\ce{H2SO4}$ are both attached to oxygen. But in $\ce{H3PO3}$ two of the three hydrogens are attached to oxygen and the other hydrogen is directly attached to phosphorous. ...

2

It reacted with the baking soda and is no longer sulfuric acid, but much safer sodium sulfate. If you're unsure, add more baking soda until it no longer fizzes. The remaining white powder is a mix of baking soda or $\ce{NaHCO3}$, and sodium sulfate, $\ce{Na2SO4}$. It safe to wipe up with a damp rag and fairly harmless to touch. Just avoid getting the ...

0

The indicator may slowly disappear after the titration because it is reacting with the air. As it reacts with chemicals in the air (CO 2 for example) which causes the indicator to be slowly disappear from the solution.

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$\ce{HSO4-}$ is acidic ($\mathrm pK_\mathrm a = 1.99$) yet also reacts as a nucleophile e.g. in the acid-catalysed hydration of olefins, which according to my mechanism lecture procedes via a sulphate diester intermediate. If I thought for long enough, I probably could come up with a basic compound that acts as an electrophile in a given situation. However,...

3

More resonance structures does not necessarily mean more stabilization. Phenolate has a negative charge at an oxygen atom which cannot be shared without "disturbing" the aromaticity of the ring. This is in part because in the resonance structures drawn, there are negative charged carbons within the aromatic ring, which either implies that: The ring is ...

1

Using the definition of $\mathrm{pH}$ (which is a log value) i.e. the difference of $\mathrm{pH}~1$ value is 10 folds difference in real terms. You have $\pu{100 ml}$ of $\ce{NaOH}$ @ $\mathrm{pH}~13.$ If you dilute by $10$ times, then the new $\mathrm{pH}$ will be $12,$ so you'll need to dilute it another $10$ times to reach $\mathrm{pH}~11.$ If you start ...

1

$$\ce{Mn^{2+} + Cr2O7^{2-} -> Mn^{3+} + Cr^{3+}}$$ If you were to balance this reaction, using the appropriate molecules of water and protons, you'd get: $$\ce{ Mn^{2+} + Cr2O7^{2-} + 14H+ + 5e- -> Mn^{3+} + 2Cr^{3+} + 7H2O }$$ The presence of protons the left side of equation suggests that this reaction has a higher rate when the concentration of ...

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In this solution, there are two sorts of H+ ions, those coming from added HCl, whose concentration is 10-9 M, and those coming from the water which are unknown, ans so described by x. But the concentration of OH- is also x. So Kw may be written : Kw = (x + 10-9)x = 10-14. If you solve this equation, you find : x = 0.999·10-7 The total concentration of H+ ...

1

Most of $\mathrm{pH}$ calculations make simplifying assumptions and one must determine if they are justified for the particular case. Simplification for strong acids $$\mathrm{pH}=-\log{[\mathrm{acid}]}$$ implies $\pu{[\mathrm{acid}] >> 10^{-7} mol/L}$. Because water dissociation constant $K_\mathrm{w}=\ce{[H+][OH-]}=\pu{10^{-14} mol^2/L^2}$, ...

1

The article text itself does go into details. The first thing to note: while aromaticity on the larger scale is retained in your structures 3 and 4, this is only true for the 10-π-electron system as a whole. In many of these types of 10 π systems made up of a six-membered and a five-membered ring, the two rings are not equal with the double bond ...

1

Chromic acid can well be stored in glass bottles with stopper/lid but should be kept away from any organic compounds. Chromic acid is a dangerous oxidising agent and incompatible with various organic compounds. Also, it should be well marked with proper label and hazard symbol to distinguish it from other mineral acids. It has a decent shelf life and can be ...

2

There are a so-called acid error and an alkaline error with glass electrodes. Which means that the pH electrode shows a systematic bias when your solution is too acidic or too basic and if it contains lot of sodium ions. The value which you quote for +13 are unreliable. So if you are bubbling carbon dioxide into NaOH solution, you are indeed consuming NaOH ...

1

It seems the most used way is reaction of sulphuric acid with salts of volatile mineral acids : $$\ce{H2SO4 + NaCl -> NaHSO4 + HCl ^}$$ Reaction with excess of the acid $$\ce{H2SO4 + NaOH ->[H2SO4] NaHSO4 +H2O}$$ has several drawbacks: It is much more exothermic than the former one It releases extra water It needs somewhat diluted solution not to ...

2

This is not the answer OP would expect because I couldn't find metal complexes of type $\ce{[M(H3O)_x]^{y+}}$ (the reason for non-existence(?) is mentioned in the comments) but I did find a complex of an organic compound where hydronium ion act as a ligand i.e a complex of 18-crown-6 and hydronium ion(emphasis mine): The observation that cyclic crown ...

3

In strongly basic solutions, phenolphthalein is converted to its $\ce{In(OH)^3-}$ form, and its pink color undergoes a rather slow fading reaction and becomes completely colorless above $\mathrm{pH}= 13$. wikipedia So the strong alkali is very probable reason, but bleachers or other compounds reacting with phph cannot be eliminated.

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To answer this question, we have to assume that the given buffer solution is an ideal solution of which the total volume of it always equals to the summed volumes of sodium ethanoate ($\ce{NaOAc}$) and $\ce{HCl}$ solutions when they are added together. It should also be assumed that $\mathrm{p}K_\mathrm{a}$ of ethanoic acid (acetic acid; $\ce{HOAc}$) is ...

1

TLDR: Sulfuric acid act as catalyst in the isomerization reaction of parafin hydrocarbons and sometimes it produce undesired sideproducts like sulfonate salts, napthenic acid, bisulfite ions etc. from incomplete oxidation. It follows "hydrogen exchange mechanism. Long answer: @andselisk cited some papers that shows that sulfuric acid can act as a catalyst ...

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Salts do not have any idea they are in a buffer solution. They interact with $\ce{H2O, H+, OH- }$ according to their respective equilibrium constants and $\mathrm{pH}$ of solution, that determine the concentration ratio of the respective conjugated acid/base pairs.

1

Water autohydrolyzes, or autodissociates, or autoionizes, to produce a very small amount of H+ and OH- ions. The product of their concentrations is 10e-14. Most salts that dissolve in water dissociate into ions. Often, one of these ions will have a strong attraction for H+ or OH- and tends to reduce the concentration of that ion in the solution. But since ...

1

At $\mathrm{pH}=\mathrm{p}K_\mathrm{a}=3.75$ , there will be 50% of non-dissociated formic acid and 50% of formiate. You need 50 % of stoichiometric amount of hydrochloric acid to convert 50% of the formiate to the acid. If we consider the percentage as (w/w) %, then $\pu{1 kg}$ of 75% formic acid ($M=\pu{46 g/mol}$) contains $\pu{16.3 mol}$ of formic ...

5

As the significance of the two contrasting factors cannot be easily evaluated, let us first look at some evidence. Wan, Modro & Yates (1980) reported the $\ce {pK_a}$ values of the conjugate acids of the various lactams, as shown in the table below: \begin{array}{|c|c|c|c|} \hline \text{Lactam} & pK_a\\ \hline \ce{$\beta$, 4} & -0.96\\ \hline \...

2

In simplistic terms, Arrhenius acids are molecules while Arrhenius bases are ionic compounds. Much like $\ce{BaCl2}$ – another ionic compound – it is a good first rule of thumb to assume it completely dissociates into its respective ions: one $\ce{Ba^2+}$ and two single-charge anions. You could say that barium were never really connected to either hydroxide; ...

-1

In3,5 dimethyl 4 nitro phenol , the nitro group is between two ortho methyl groups . Therefore due to this steric inhibition of resonance occurs and this nitro group is pushed out of plane by two methyl groups. Such that nitro group does not take part in the resonance. And there have no extra stable structure. That is why it is less acidic than2,6 dimethyl 4 ...

2

I think OP is confused with the colorimetric method of detection of piperine, which uses the concentrated sulfuric acid as one of reactant with chromotropic acid, 1,8-dihydroxynaphthalene-3,6-disulfonic acid (Chromotropic Acid Test; Ref.1 & 2). Accordingly, this colorimetric method, developed in 1965, relied on hydrolyzing the methylenedioxy group of ...

1

The explanation given to you is rather incorrect. Dilute sulfuric acid is added to iron(II) or even iron(III) salts is added to prevent hydrolysis of the salts. What happens when you don't add an acid to iron(II) solution in water. With time, you will see that a brown precipitate is forming and settling to the bottom. Iron forms hydroxides which are very ...

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Resonance structures can only be drawn for single compounds. Rephrased: if a set of resonance structures are to be valid, then all atoms (nuclei) must be at exactly the same positions. Thus, when asked to draw resonance structures of e.g. phenol or nitric acid, you cannot deprotonate or transfer protons. All protons must be exactly at the same spot in all ...

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