New answers tagged

1 vote

Henderson-Hasselbalch equation and degree of dissociation

The equilibrium constant expression for a weak acid is: $$K_\mathrm{a} = \frac{\ce{[H3O+]}_\mathrm{eq} \ce{[A-]}_\mathrm{eq}}{\ce{[AH]}_\mathrm{eq}}\tag{1}$$ for the reaction $$\ce{AH(aq) + H2O(l)<=...
  • 35.3k
2 votes
Accepted

What results from the neutralization of copper citrate with Na2CO3

Copper ion forms with citrate stable chalate, that is not disturbed even by addition of sodium carbonate, what is used in Benedict's reagent(*) for detection of reducing sacharides. Copper etching: $$\...
  • 34.1k
4 votes

Why is CrO3 an oxidising agent, but WO3 is not?

We can look at both ionization energy and coordination aspects. Both factors differentiate the relative stability of both $\ce{MoO3}$ and $\ce{WO3}$ from the strong oxidizing tendency of $\ce{CrO3}$. ...
  • 46.8k
2 votes

How to prepare iron(II) carbonate from iron(III) chloride?

This is the simplest method I can think of: $\mathrm{2FeCl_3+Fe\rightarrow3FeCl_2}$ $\mathrm{FeCl_2+Na_2CO_3\rightarrow FeCO_3+2NaCl}$ It only uses iron metal and sodium carbonate, which are readily ...
0 votes

How to synthesize lanthanum(III) chloride & Cerium(III) chloride from their oxides?

Wikipedia mentions synthesis of $\ce{LaCl3}$ from $\ce{La2O3}$: Anhydrous lanthanum(III) chloride can be produced by the ammonium chloride route. In the first step, lanthanum oxide is heated with ...
6 votes

Why doesn't oxygen form cyclic pentagonal compounds with itself?

Sulfur does form ring compounds, so why not oxygen? You're not wrong to wonder, but I think people are reacting to the implication that this species has: [no] weak bonds Consider hydrogen peroxide H-...
0 votes
Accepted

Why is solubility affected by temperature?

Firstly that is strictly not true. Most solutes that are gaseous at the temperature will be less solvated the higher the temperature of the solvent liquid, for instance. There are other relevant ...
  • 2,639
0 votes

Why Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) reaction really occurs?

Copper is attacked by molecular $\ce{HNO3}$, and neither by $\ce{H+}$ nor by $\ce{NO_3^-}$ ions. The equation is : $$\ce{3 Cu + 8 HNO3 -> 2 NO + 4 H2O + 3 Cu(NO3)2}$$ At high $\ce{HNO3}$ ...
  • 25k
0 votes

Why Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) reaction really occurs?

It is true that Copper has a negative oxidation potential hence H+ ion is unable to oxidise $\ce{Cu(s)}$ to $\ce{Cu+}$ or $\ce{Cu}^{2+}$. It is the reason why Copper does not react with strong mineral ...
6 votes

Can a sulfur atom form six single bonds with six other sulfur atoms?

Answering the question posed in the title: yes, and under relatively mild conditions. A hexacoordinated sulfur is present as μ6-sulfido group $(\ce{S^2-})$ linking two $\ce{[Mo3S(S2)3]^4+}$ cores ...
  • 36.9k
11 votes

Why are sulfites often ignored in soil studies?

I think Andrew is correct in his statement: I think it's generally assumed that sulfite has a short lifetime in soil, decomposing to $\ce{SO2}$ gas or getting oxidized to sulfate. Sulfur is found in ...
2 votes

Can a sulfur atom form six single bonds with six other sulfur atoms?

Under high pressure [a six-coordinate form of elemental sulfur is known 1. As one might expect, a higher pressure is required to achieve this phase with sulfur than with its heavier and more nearly ...
  • 46.8k
-2 votes

Does Isopropyl alcohol (isopropanol/rubbing alcohol) react with polyethylene terephthalate?

It does not. Gallon quantities of isopropyl alcohol typically ships in HDPE bottles which are less resistant to alcohols than PET. Chance of having a reaction between rubbing alcohol (which is 30% ...
  • 94
7 votes
Accepted

Why are sulfites often ignored in soil studies?

This article(ref.) gives you your answer: While techniques are available for determining the concentration of most S-oxides in soil, determination of soil sulphite has been largely neglected. This is ...
3 votes

Hydrate forms causing complications with gravimetric analysis of ferric phosphate

As Poutnik suggested, you shouldn't use unestablished methods for gravimetric analysis for analytic determination. The Ref.1 have showed one of the original published method for phosphate analysis by ...
8 votes

Why does potassium bifluoride exist whereas bichloride does not?

The bichloride ion, including isolated salts, has in fact been known since 1954 [1]; but it appears to require relatively bulky counterions whereas bifluoride has a broader range of stable salts. To ...
  • 46.8k
13 votes

Why does potassium bifluoride exist whereas bichloride does not?

The bichloride ion $\ce{HCl2^-}$ does exist, but it requires other environment than usual solutions in water. E.g. solution of $\ce{[N(CH3)4]Cl}$ salt and undissociated $\ce{HCl(solv)}$ in ...
  • 34.1k
1 vote

How to determine the cell potential of chromium(III) — permanganate cell?

You have asked two questions. Regarding "which one is being reduced" and "which one is being oxidized", you can clarify that by using the Nernst equation $$\Delta E=\Delta E^\circ-\...
0 votes

Nickel(II) acetylacetonate crystals coming out blue

You obtained the dihydrate complex of AAN. If you want to obtain green crystals, you should use azeotropic evaporation to remove crystal water. Then you will have green product - anhydrous AAN.
0 votes

Why is gunpowder urinated on in Blood Meridian?

In Literature stackexchange we have this answer which indicates firstly that urine is something that can be used and secondly that saltpeter probably can't be extracted as fast as portrayed in the ...
  • 425
3 votes

Does KMnO4 Oxidize Alpha-Beta Unsaturated Aldehydes?

As Waylander predicted, in aqueous solutions, the first reaction would have been the oxidation of aldehyde to corresponding carboxylic acid (in here, cinamaldehyde to cinnamic acid). When that happens,...
5 votes

Why are fluorine-19 NMR spectra less affected by paramagnetic centers than other common nuclei?

$\ce{^{19}F}$ has similar NMR properties to $\ce{^1H}$ except in particular for the much larger chemical shift tensor terms and resulting larger chemical shift anisotropy (CSA). As a result CSA ...
  • 20.1k
7 votes

Does high pressure reverse reaction between zinc and sulfuric acid?

Any equilibrium calculation involving ordinary compounds that gives a pressure of $10^5$ bar or more is probably not realistic. Chemical bonds can deform and rearrange under such pressures and thus ...
  • 46.8k
12 votes
Accepted

Does high pressure reverse reaction between zinc and sulfuric acid?

As a very rough estimation of pressure when the hydrogen redox potential equals zinc standard redox potential, we can use the extrapolation of the Nernst equation: \begin{align} E^\circ_\ce{Zn/Zn^2+} &...
  • 34.1k
5 votes
Accepted

Can I convert copper(II) acetate or carbonate to copper(II) sulfate?

Practical approach Arguably, the easiest way is to trade/exchange your chemicals — copper(II) salts and elemental sulfur — for copper(II) sulfate, which should be readily available for purchase online ...
  • 36.9k
6 votes
Accepted

Crystal structures exhibiting dimeric arrangement of tetrahedrally coordinated cations

Given the unit must be isolated and should not be the subunit of an ionic network, the following graph model for CCDC ConQuest's (ver. 2022.3.0) query with restraints based on connectivity $(\mathrm ...
  • 36.9k
2 votes
Accepted

What is ionic reaction equation for reaction between carbon dioxide and limewater?

$\ce{CaCO3}$ is a precipitate. It is not made of separated $\ce{Ca^{2+}}$ and $\ce{CO3^{2-}}$ ions. So the equation is : $$\ce{Ca^{2+} + 2 OH^- + CO2 -> CaCO3 + H2O}$$ This equation may be ...
  • 25k

Top 50 recent answers are included