Questions tagged [inorganic-chemistry]

Inorganic compounds generally do not have C-H bonds, while organic compounds do have such bonds. The distinction between inorganic and organic chemistry, however, is far from absolute.

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4
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2answers
518 views

Considering the d-d transition how, does tetracyanidonickelate(II) ion exist as a colored complex?

As I refer on google, the resources indicated that, the d block elements which have unpaired electrons as in their ions, when they are making complexes with ligands, they can absorb different ...
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0answers
84 views
+100

Activators for non-sulphide compounds in froth floatation

I was recently studying about Metallurgy. Concise Inorganic Chemistry by J. D. Lee claims the process of froth floatation can also be applied to non-sulfide ores such as Malachite ($\ce{CuCO3.Cu(OH)...
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1answer
4k views

Explaining the colour change in the potassium permanganate titration of iron(II) ions

In the redox titration: $$\ce{MnO4- + 8 H+ + 5 Fe^2+ -> Mn^2+ + 4 H2O + 5 Fe^3+}$$ the colour change which occurs is purple to colourless, because of the decreased concentration of permanganate ...
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1answer
485 views

Reaction of aqueous sodium carbonate with aluminum foil

Aqueous sodium hydroxide is known to react with aluminum foil in an exothermic, hydrogen-gas releasing reaction like $$\ce{2NaOH(aq) + 2Al(s) + 2H2O(\ell) → 2NaAlO2(aq) + 3H2(g)}$$ However, on ...
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0answers
16 views

IR vs Raman Activity from Character Table [on hold]

For the molecule trans-1,2-dichloroethene (point group $C_\mathrm{2h}$) determine using only the two C−Cl bond elongation vectors the symmetries of the possible C−Cl stretching modes. The $z$-axis is ...
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0answers
14 views

GSR (skin conductance) on leather [on hold]

In terms of GSR, skin conductance is used to measurfe and analyze differences in conductivity. However is it possible that leather (aka tanned and dead skin) has conductance values like living skin? I'...
3
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0answers
79 views

Why my boiling pot turned black?

Recently I ran out of dish washing detergent, so I decided to pick up one of the recipes online, to make my own "ecological" dish washing detergent alternative. The recipe was: Mix ingredients: ...
7
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1answer
465 views

Dissolution of Lithium in Methanol

Easy question to kick off my chemexchange membership! I'm learning chemistry in my spare time, and fittingly for a video art project I'm doing, decided to try a simple inorganic(?) procedure to make ...
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1answer
705 views

Is there any difference between negative electron gain enthalpy and electron affinity?

Electron affinity is the amount of energy "released" during the addition of an electron in the valence shell of an isolated gaseous atom. The sign convention is opposite to that of thermodynamics ...
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1answer
45 views

Does bicarbonation require water?

In an aqueous solution of $\ce{NaOH}$ exposed to the atmosphere one can probably expect some degree of $$\ce{NaOH(aq) + CO2(g) -> NaHCO3 (aq)}$$ But, what would happen if just a solid block of $\...
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0answers
25 views

Why is [Fe(CN)6]3- more stable then [Fe(ox)3]3- despite being a non-chelate?

I was reading up on how chelation leads to more stability of a complex, and then I came across this weird trend given by my professor in class as a contradiction, with no explanation. I'm curious what ...
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1answer
39 views

Why does $\ce{NCl3}$ have $sp^3$ hybridization and not $sp^2$ because of back bonding? [on hold]

I was asked the the hybridization of Nitrogen Chloride, and my thought process was that it should be $sp^2$ because of back bonding. The lone pair on the Nitrogen will be donated to the vacant d ...
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1answer
27 views

Synthesis of dibasic calcium phosphate dihydrate [on hold]

How to prepare dibasic calcium phosphate dihydrate $(\ce{CaHPO4·2H2O})$ from anhydrous salt $(\ce{CaHPO4})$? I'm specifically interested in a dihydrate, not mono- or trihydrate.
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0answers
25 views

Methyl Radical. Lewis Acid or Not?

Is methyl radical a lewis acid ? According to me it is a lewis acid as any species can be considered as a lewis acid if it can accept an electron in its LUMO.
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2answers
371 views

How to convert Mn2O3 to Mn3O4?

I was preparing $\ce{Mn3O4}$ but it was when characterized by XRD, a $\ce{Mn2O3}$ phase existed. Now how can I convert $\ce{Mn2O3}$ to $\ce{Mn3O4}$?
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1answer
35 views

Cupric and cuprous copper [duplicate]

Copper has two chlorides: $\ce{CuCl2}$ and $\ce{CuCl}.$ Copper reacts directly with chlorine to form a copper(II) chloride. Why doesn't it form copper(I) chloride? Is it because $\ce{CuCl2}$ is more ...
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0answers
16 views

What are the factors on which the activity constant mainly depend? [on hold]

Particularly the problem arises when we have to take ratios of activities to think about whether we can cancel the activity constant.Please answer this with close reference to things like solute,...
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0answers
40 views

I conducted a neutralisation reaction at school and there was fizzing. How is this possible? [closed]

The reaction was $$\ce{HCl(aq) + NaOH(aq) -> NaCl(aq) + H2O(l) + Energy}$$
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0answers
21 views

Comparing the order of intermolecular forces [on hold]

Order of intermolecular forces: $$\ce{CO2} > \ce{CH4} > \ce{N2}$$ Here, van der Walls force increases with molecular size. Thought $\ce{CH4}$ is $16 \,\rm g$, it has stronger molecular force ...
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0answers
34 views

Finding the maximum mass of copper(II) nitrate that can be produced from a given mass of copper [on hold]

I have the following chemical equation: $$\ce{Cu(s) + 4 HNO3(aq) -> Cu(NO3)2(aq) + 2 H2O(l) + 2 NO2(g)}$$ The mass of copper in the equation is 0.6355 g. I am trying to find the maximum mass of ...
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1answer
20 views

Using a weak acid to prevent the precipitation of Mg(OH)2

I have this exercise in my chemistry book, and I have been staring at it for so long but unfortunately I have no single idea what to do and where to start. I will be so thankful for any help. $0.05$ ...
8
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1answer
423 views

Ag-Sn-Cu Phase diagram to formulate homogenization temperature / duration

I am working on Ag-Sn-Cu alloy phase diagram to figure out the best temperature / duration to homogenize the alloy (annealing). The %age of elements in the alloy are Ag - 40 % Cu - 27.8 % Sn - 32.2 % ...
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1answer
74 views

Terminology for describing nuclei participating in metallic bonds

I've read many times that in metals (for example sodium metal), what constitutes the crystal lattice is an arrange of atoms, since no electron is given or lost, they are just shared between all the ...
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0answers
24 views

How can I obtain CaCO3 from CaO? [closed]

How can I obtain CaCO3 from CaO? I feel the backward rxn of decomposition of CaCO3 won't really be feasible. Is there any other way?
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35 views

Method for making graphene by reducing carbon dioxide on gallium surface [closed]

I had an idea where you take gallium in a vacuum and while it’s under a vacuum you spread it out across a flat surface such as a glass slide. You would want to spread it while under a vacuum to ...
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1answer
66 views

Making hard water

Does anyone know how to make hard water with a hardness of 200+ ppm in terms of $\ce{CaCO3}$? I live in Seattle and we have very soft water and we need hard water for testing purposes. Obviously you ...
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0answers
30 views

How do elemental halogens get their colour?

I learnt that in halogens the colour is due to transfer of electrons from HOMO to LUMO during excitation but I have trouble understanding what that means. Also I don't understand how iodine is ...
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0answers
21 views

Why is BF3 hard while BBr3 is borderline(HSAB concept)?

This is a table given in a text book regarding hard acids How come BF3 is a harder acid than BBr3? My reasoning: To check which is harder: 1.Both difficult to polarize 2.Both similar in size It ...
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1answer
42 views

Converting AlCl3 to Al2O3

Since oxygen is more electronegative than chlorine, if I introduce $\ce{O2}$ gas to $\ce{AlCl3}$ and apply some heat, will the chlorine be replaced by oxygen, resulting in $\ce{Al2O3}$ or $\ce{Al(ClO2)...
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1answer
47 views

Why are the phase diagrams showing $G_s$ and $G_l$ situated so close on one end and then widens up at the other extremes? [closed]

With reference to the phase diagrams drawn in b and d why are the Gibbs phase lines coming closer from being so further apart?
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1answer
84 views

Why can't O form OF6?

At first I thought that the reason is what I was taught, the absence of vacant d-orbitals but then I did some research. Most of the answers stated what I initially thought but one particular answer ...
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2answers
40 views

Why is the product of the reaction “Bi + O2” Bi2O3 instead of Bi2O5?

I am stuck on a homework question that states: A piece of solid bismuth is heated strongly in oxygen. The answer key states the answer as $\ce{Bi + O2 → Bi2O3}$. However, it is to my understanding ...
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1answer
38 views

Mass percentage of water in hydrate? [closed]

1.034 g of a metal sulfate hydrate was heated to a high enough temperature to remove all the water of hydration. The mass of the anhydrous salt left behind was found to be 0.956 g. What is the mass ...
2
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0answers
45 views

How to charge titanium dioxide particles for a DIY e-paper capsule? [on hold]

I'm trying to make a single e-paper capsule (1 cm × 1 cm) at home. At first, I tried to charge the $\ce{TiO2}$ particles by putting them in $\ce{H2O}$ with $\ce{NaOH}$ and then putting that whole ...
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1answer
746 views

what is the mass of chromium in this sample?

If the total number of atoms in a sample of potassium dichromate is $2.13\cdot10^{24}$ , then the amount of chromium in this sample is? the answer that I've come up with is $367.64\ \mathrm g$ but in ...
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1answer
467 views

Distinguishing between octahedral and tetrahedral holes

I know the question sounds a bit silly and there are many similar answered questions but my 3D visualization (imagination) is very bad. There are some images of octahedral and tetrahedral holes but ...
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7answers
20k views

Is dehydrating copper(II) sulphate pentahydrate a chemical or physical change?

Is removing the waters of hydration from $\ce{CuSO4 * 5H2O}$ a chemical or physical change? Sorry for the trivial question. I get varying answers across the net.
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0answers
22 views

Why does equilibrium reactions take place at constant temperature? [closed]

I have realized that whenever we have chemical equilibrium reactions and also certain invariant reaction like Monotectic,Syntectic etc.,the only common link is the fact that they take place at ...
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0answers
37 views

What is the degree of freedom of the calcium carbonate dissociation reaction?

Question $\ce{CaCO3}$ dissociated in a closed system according to the reaction: $$\ce{CaCO3(s) -> CaO(s) + CO2(g)}$$ Assuming the reaction is in thermodynamic equilibrium, what is/are ...
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0answers
57 views

Primitive Technology - Extract Silica and Sulfur from ash

Given some plant ash containing silica and sulfur, we need to find a way to extract the silica and sulfur using only resources available to a primitive person stuck on an island, with access to a ...
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0answers
41 views

Reaction of getting jarosite from pyrite

I am doing a PhD about archaeometry in order to study the contaminations and alterations that occur to the ceramics which are buried in a marine environment. In my research, I have found pyrite in ...
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1answer
56 views

What materials are resistant to hot chlorine?

I'm looking to do an experiment involving hot chlorine gas (900 Celsius), however at the moment the only material I'm aware of that could cope with this is Hastelloy's C-22 alloy. What other ...
3
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0answers
7k views

Why do NaNO3 + Al + NaOH yield ammonia?

From Russian test problem 4301: $$\ce{3NaNO3 + 8Al + 5NaOH + 18H2O -> 8Na[Al(OH)4] + 3NH3(g)}$$ How does ammonia evolve here? Is it that we get hydrogen gas evolving in the reaction between Al ...
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1answer
29 views

Concentrating sulfuric acid

Since calcium oxalate is 3000 times less soluble than calcium sulfate, would it be possible to concentrate sulfuric acid from let's say 50% solution using following steps? : adding calcium carbonate ...
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2answers
329 views

Oxidation states of boron

I have just been looking at https://en.wikipedia.org/wiki/List_of_oxidation_states_of_the_elements and found that boron has a -5 oxidation state. I would like to know which boron compounds form ...
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0answers
26 views

Lewis structure and bond order of polyiodides

I am trying to draw the lewis structure of triiodide, pentaiodide and heptaiodide-anions. But I am not sure about them, especially not about the heptaiodide-anion (see image). The second question is,...
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1answer
72 views

Black & Green Nickel Oxide-Supplemental

A previous question (April 2017) asked about black $\ce{NiO}$ did not supply any answer. Sadly, such a referral only deters colleagues from commenting on the current question. There is a great deal ...
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2answers
55 views

Out of CaCO3 and MgCO3, which has higher electrical conductivity of molten solution? [closed]

According to me, Mg will be more hydrated and so should have lesser conductivity. Is that correct?
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0answers
26 views

What will be the Lewis acid and Lewis base in the reactions between aluminium(III) aqua complex and hydroxide?

$\ce{Al^3+}$ in water will be hydrated, formed a complex ion $\ce{[Al(H2O)6]^3+(aq)}$ that can neutralize hydroxide ion according to the following reactions: $$ \begin{align} \ce{[Al(H2O)6]^3+ + ...
2
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1answer
40 views

Why there are more examples of carbonylate anions than metal carbonyl cations?

I know that metal carbonyl complexes that do not follow EAN rule or 18 electron rule try to achieve that by gaining electron (forming carbonylate) or loosing electron (forming carbonyl cations). But ...