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23
votes
3answers
13k views

Please explain why dioxygen difluoride is so dangerous

I just read this article that mentioned that dioxygen difluoride is very dangerous. The terms it uses are "awful", "violently hideous" and "deeply alarming". But I couldn't get a handle on exactly ...
4
votes
0answers
146 views

Where do the rate laws for the Chlorine Dioxide-Iodine-Malonic Acid reaction come from?

After reading a section on this particular oscillatory reaction, something started bugging me about it. However, let me lay out the basis of my question. From what I've researched, Lengyel and ...
3
votes
1answer
63k views

Why are elements on the right side of the periodic table nonmetallic and gas at room temperature?

Elements on the left side of the periodic table tend to be solid and metallic, elements on the right side of the periodic table are nonmetal and tend to be gases at room temperature, and the semi-...
7
votes
1answer
269 views

Iodine clock with moving bands

Has anyone seen a version of the iodine clock reaction where instead of the system oscillating between clear and blue it shows blue bands travelling down the vessel? I ask because someone not unknown ...
3
votes
2answers
501 views

How different are molecule with same connectivity

Let us represent molecules by graphs (atoms are vertices and bonds are edges). Let $A$ be the adjacency matrix of the molecular graph. $A_{ij} = b$ where $b$ is either binary: 0 when atom i and j are ...
0
votes
1answer
2k views

Ksp of Manganese Phosphate

I can't find the $K_{sp}$ value for Manganese Phosphate ($\ce{Mn_3(PO_4)_2}$) anywhere online. Has it been measured? What is it?
2
votes
3answers
15k views

What is the freezing point of sulfuric battery acid?

As we all know, the freezing point of absolute sulfuric acid is 10 °C. The average lead-acid battery (sulfuric) uses ~30% sulfuric acid, and has a freezing point much lower than 10 °C. What ...
7
votes
1answer
917 views

Common Elemental Termolecular Reactions

Are there any common elemental (single-step) reactions with three reactants? Everything I've found either says that they're very rare, or can be broken down into two bimolecular steps with combined ...
0
votes
2answers
270 views

Mol file of Morphine

I am using the Morphine mol file and I'm attempting to create a matrix which contains a table of the atoms and how they bond similar to a ball and stick format. In the mol file bond block listed ...
0
votes
2answers
1k views

What is the multiplicity of this signal in the ¹H NMR of glutamine in D₂O

The 2 Hydrogens near the carbonyl (the lower 2 $\ce{H}$s are not bonded to the nitrogen) should be the most deshielded so I think they appear as the rightmost peak in the NMR. Are these 2 $\ce{H}$s a ...
6
votes
3answers
11k views

Isopropyl alcohol forming peroxides

I read in many MSDS that Isopropyl alcohol tends to form peroxides (by reacting to air OR light) which may explode when they reach a given concentration. For example: http://nj.gov/health/eoh/rtkweb/...
3
votes
1answer
710 views

Why are the oxide materials insulating?

Why are the oxides usually insulating? It would be nice to get an explanation with chemistry terms (e.g., electronegativity, electron affinity, etc...) and a different explanation involving the ...
4
votes
1answer
38k views

How to calculate the pH of a buffer after HCl was added?

A buffer is made from $50~\mathrm{mL}$ of $1.0~\mathrm{M}$ benzoic acid, $K_a = 6.3\cdot10^{-5}$, and $50~\mathrm{mL}$ of $1.0~\mathrm{M}$ sodium benzoate. a) Calculate the pH of this buffer For this ...
3
votes
2answers
1k views

Why is lead sulfide found in nature, whereas lead oxide is less common?

This question probably applies to other heavier metals as well. The only rationalization I can figure out is that lead in the +2 oxidation state (which is most common) is a borderline soft acid and ...
4
votes
2answers
2k views

Can you carbonate a non aqueous liquid?

We have a home carbonator for makeing seltzer. It blows $\ce{CO2}$ under high pressure into water. Could I use it to carbonate corn oil? Is $\ce{CO2}$ soluble in a no aqueous solution?
5
votes
1answer
23k views

How can I know the colour change of this reaction?

After you react rotundone ($\ce{C_{15}H_{22}O}$) with water it loses all of the double bonds (except the carboxylic bond, $\ce{C=O}$) and gets two of the functional group $\ce{-OH}$ (alcohol). Two ...
0
votes
2answers
721 views

Balancing a chemical equation, but with an incorrect mole ratio

I'm wondering if it's possible to balance a chemical equation with an incorrect mole ratio. I have the unbalanced equation $\ce{AgNO3 + Cu -> Ag + Cu(NO3)2}$, I have a $2:3$ ratio of $\ce{Cu}$ and ...
3
votes
1answer
31k views

Smallest nearest neighbor distance among elements

Of all the elements in periodic table, which one has smallest nearest neighbor distance? I tried searching on net, but could not find any reference. My earlier guess was one which goes into FCC with ...
2
votes
1answer
3k views

Using Arrhenius equation to calculate the ratio of two reaction rates

For two reactions, $$\begin{align} \ce{A ->[$k_1$] B} \tag{1} \\ \ce{A ->[$k_2$] C} \tag{2} \end{align}$$ you have determined that the activation energies are $\pu{71.9 kJ/mol}$ for $(...
0
votes
1answer
550 views

Acids / Bases - Need some clarity for final exam [closed]

I'm studying for my final exam, and these are the questions I got wrong on the mid term, could anyone help correct me? I know people are against giving answers for homework, so I must add that is now ...
3
votes
1answer
2k views

Difference between the terms "autocatalysis" and "(branching) chain reaction"

Is there a technical difference between the terms "autocatalysis" and "branching chain reaction"? They both seem to refer to something very similar, namely sequences of reactions in which one of the ...
8
votes
2answers
12k views

What is the difference between graphite oxide and graphene oxide?

I am considering making a sheet of graphene using the LightScribe technique and I have read that I need graphite oxide. However when I look up graphite oxide for sale, graphene oxide pops up. Are ...
9
votes
5answers
95k views

Why does the melting point get lower going down the Alkali Metal Group with increase in atomic number?

Why does the melting point get lower going down the Alkali Metal Group with increase in atomic number?
2
votes
1answer
151 views

I'm looking for a substance that can be used as an adhesive, but that will burn without producing any ash

I need to 'adhese' paper to plastic, but I need the adhesive to be flammable and quick burning, but without producing any ash or too many toxic fumes. I know this is an absurd question, but does ...
8
votes
3answers
27k views

How to get the valencies of elements?

How to find the valencies of elements by using its distribution of electrons? Please explain the method in simple words. Do you have to study the valencies or is there a simple way of remembering? PS:...
5
votes
1answer
1k views

What is the substituent on this benzaldehyde? (MS attached)

I have no clue what the substituent may be. The molar mass of the unsubstituted benzaldehyde is 105 g/mol (subtracting one H, where the substituent will be). So the substituent is around 30–33 g/mol. ...
-3
votes
1answer
5k views

which chemical element has the lowest boiling point? [closed]

which chemical element has the lowest boiling point? Is it Helium(He) or is it Hydrogen(H)? Hydrogen is lighter than Helium.
5
votes
2answers
3k views

What is a "period" of the periodic table?

I'm familiar with the periodic table / periodic system, but I wonder why it's called "periodic" since there seems not much periodic about (there seems to be little or no predictability of which ...
2
votes
1answer
12k views

Standard electrode potential of a galvanic half cell is zero at equilibrium at standard conditions?

At standard conditions(at 1atm pressure and unit activity(1molal or 1molar concentration)of all dissolved compounds),the electrode potential is equal to the standard electrode potential by the Nernst ...
4
votes
2answers
196 views

Why do frying pans stick less with heat?

I know this is simple, compared to most questions asked here, but I notice this several times a week and I'm curious. I notice if I break an egg and drop it into the frying pan, and the pan is still ...
3
votes
2answers
964 views

Minimizing Gibbs free energy with Helmholtz free energy expressions

If I have an expression for the Helmholtz free energy (from statistical associating fluid theory for a polymer system), can I still find the Gibbs free energy minimum under constant $T,P$ conditions? ...
4
votes
1answer
191 views

How am I to interpret the phrase "a solution of acid"?

The question title is a bit odd, I couldn't find a plainer way of saying it. I'm given the concentration and conductivity of a solution of a particular acid, let's just call it $\ce{AH}$. I then have ...
3
votes
1answer
869 views

Number of bonds in a Lewis Structure [duplicate]

I'm asked to find the Lewis Structure of sulfuric acid, $SO_4H^-$. After struggling for a while, I sumply looked it up. How can this be? Sulfur has 6 electrons in its valence shell, so it should ...
1
vote
1answer
210 views

Spontaneous inequilibrium in a gas in an isolated system?

Can an isolated system(of several phases) in equilibrium by itself move out of equilibrium? if a system contains for example an inflammable gas dispersed with another combustible gas such that the ...
48
votes
5answers
8k views

How can antibonding orbitals be more antibonding than bonding orbitals are bonding?

In molecular orbital theory, the fact that a bonding and antibonding molecular orbital pair have different energies is accompanied by the fact that the energy by which the bonding is lowered is less ...
6
votes
2answers
6k views

Spontaneous explosion of a bottle containing alcohol and milk

A friend of mine gave me a bottle of home-made liquor which is a concoction of pure alcohol and sweetened milk. I accepted his gift happily and then I put the bottle in my cocktail cabinet. After an ...
3
votes
3answers
12k views

Homemade preservative for natural aloe-vera gel?

I suppose this question can be extrapolated to food in general, but it is the case that I would like to know if there are any methods that would help me to keep the aloe gel fresh, i.e. avoiding it to ...
1
vote
1answer
68k views

How does the reaction Mg + O₂ → MgO occur? [closed]

$\ce{Mg + O2 → MgO}$ Magnesium, oxygen and magnesium oxide form the above equation. How? What do I need to learn to do this? atomic numbers/ valencies?
3
votes
1answer
786 views

Is there a specific term for reactions of the form A + B → C + D?

I'm working with an abstract model of chemical reaction networks. In this model, some of the reactions have the form $\ce{A + B <=> C}$ and others have the form $\ce{A + B<=>C + D}$. I'm ...
6
votes
1answer
582 views

What does under-stoichiometric or stoichiometric mean?

When people talk about oxides like $\ce{SiO2}$ or $\ce{Al2O3}$, they use expressions like stoichiometric or under-stoichiometric. I understand that this refers to the relative composition of materials,...
0
votes
1answer
191 views

Can high-tin bronze be made sharper than low-tin bronze?

I am not sure how sharpness is measured, but I do know that certain materials can be designated sharper than others, for example obsidian is said to be the sharpest material: The prismatic glass ...
2
votes
2answers
4k views

Writing the net reaction for reaction of sodium hypochlorite with hydrochloric acid and potassium bromide

I am currently taking a general chemistry course and during a lab they had us do the following procedure: Place $\pu{2 mL}$ of $5\%$ $ \ce{NaClO} $ solution in a test tube. Add $10$ drops of ...
2
votes
1answer
2k views

Alternatives to Congo Red?

I require Congo red indicator for an experiment I wish to perform involving dipping a cellulose sponge into an acid and a base. I first want to dye the cellulose sponge with Congo red, and observe ...
0
votes
3answers
347 views

How does caesium’s density change with temperature?

According to Wikipedia caesium’s density is $1.90\ \mathrm{g/cm^3}$ at $\Theta =20\ \mathrm{^\circ C}$. How does this change when $T$ changes? E.g. will it expand when melting?
1
vote
1answer
54 views

Can I deduct heteronuclear van der waals parameters from homonuclear parameters in a forcefield?

I got a forcefield (OPLS-AA in this case) that lists lennard-jones parameters for all homonuclear van der waals interactions. Is there a way to deduct the heteronuclear vdw-interaction parameters from ...
3
votes
2answers
1k views

Recreational drugs by half life

I am interested in the Biological Half Life of substances. In the previous wikipedia link, I've already found the half lives of common pharmaceutical products. I can't seem to find similar data for ...
2
votes
1answer
1k views

Explanation of the Selection rule in light of IR spectroscopy

I am in mathematics, but I am writing a paper on molecular vibrations (because you can use representation theory to handle this). I want to prove the selection-rule, but I also have to give a ...
12
votes
2answers
775 views

Can we process waste just by decomposing it to homogenous mass and extracting the elements from it?

I. e., what if we just burn trash completely or dissolve it in acid, get the resulting paste and extract pure chemical elements out of it by applying some physics and/or chemistry to it until no more ...
2
votes
0answers
244 views

How would you change the chirality of a compound such that (S,R) becomes (S,S)? [closed]

How would you change the chirality of a compound such that (S,R) becomes (S,S)? That is how would you synthesise a compound from its diastereomer?
2
votes
0answers
2k views

How, chemically, would you remove protruding phenyl groups?

How, chemically, would you remove protruding phenyl groups? I mean for instance in the molecule phenethylamine there's a phenyl group sticking out (or protruding) how would you go about removing this ...

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