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11 views

How do you use MacConkey's agar to test yogurt? [closed]

I am in Secondary school and we are testing radiation effects on yoghurt and one thing my teacher reccomended was testing through MacConkey's agar to see what happens. 1) Can someone explain in lay ...
0
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0answers
36 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 ...
-1
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0answers
22 views

Differences Between RainX and RainX Anti-Fog? [closed]

I have a question pertaining to chemistry in a practical way. As I was unable to find a more suitable community to ask, I shall ask it here. RainX, as you may already know, is a compound applied to ...
0
votes
0answers
29 views

Obtaining conformational energy from Newman projections in first place

In this source, the conformational energy from Newman projections is obtained. Is there a formula or quantum chemistry approach to obtain the values in first place (pretend that I don't know the ...
0
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0answers
28 views

Surface modelization of an electrode

I am trying to model the interaction between an electrode and a saline solution through an RC circuit. A reference electrode is placed in the saline solution to measure the voltage between the ...
-1
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0answers
45 views

Reaction between CuSO4.5H2O and NH3 [on hold]

Today in the laboratory we did a confirmatory reaction for Copper (II) in CuSO4. The reaction we carried out was adding NH4OH to a little of original salt solution. So the reaction that took place is ...
2
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1answer
71 views

What happens when a super-critical fluid is compressed?

Suppose that I have some substance with a critical temperature of 20°C. That means above that temperature, the substance exists neither as a gas nor a liquid, but instead as a super-critical fluid. ...
3
votes
0answers
32 views

CNDO/2 clarification

I wrote a piece of code on RHF using Python a while back, and figured I'd extend it to also implement CNDO/2 (yes, I know it's old but I figured it'd be easier for me.) The approximated Fock matrix ...
0
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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 ...
2
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0answers
12 views

C-C bond lengths in hydrocarbons

We had a question in a rest comparing the bond lengths of hydrocarbons fluorides, and the answer key says CF3- CF3's supposed to have a longer C-C bond than H3C- CH2--F. Why is this so? Wouldn't the ...
0
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0answers
23 views

Is the nature of both the ligands, PH3 and PF3, non-classical?

A non-classical ligand is defined as: ligand which forms complexes with transition metals only but not with other metals. $\ce{PH3}$ and $\ce{PF3}$ both are $\pi$ donor (due to lone pair with $P$ ...
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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 ...
-1
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0answers
21 views

Name of Nonmetal Polyatomic Ions [duplicate]

I'm studying for a high school chemistry test and I wanted to put a name to polyatomic ions which contain a nonmetal and oxygen. Examples include phosphate, sulfate, nitrate, ... etc. I have ...
1
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0answers
39 views

Chirality as atom feature

I have been reading some literature on molecular energy prediction using machine learning techniques and I have noticed that one of the input parameters in many of the available models is "chirality". ...
1
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0answers
58 views

Safe, low maintenance, versatile methods for electro-etching steel?

I'm experimenting with electro-etching steel. I'd like to mask off a small area (e.g. text or logo with exposed area of about 2cm x 2cm) on a steel sheet, and etch about 1mm deep. I'm trying to find a ...
1
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1answer
56 views

Differentiating between Elementary and Non Elementary reaction [closed]

Is it possible to tell just by looking(reaction's equation) that whether a given is reaction is elementary or non elementary ?
1
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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)...
0
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0answers
36 views

Changes in conductivity of CuSO4 solution after NH3 solution is added

In my high school chemistry class we are writing a lab. Originally, I wanted to measure the rate of a ligand exchange reaction at different temperatures by measuring changes in conductivity. After ...
1
vote
0answers
28 views

How to calculate size of a specific cavity in a protein for every frame in trajectory file?

Here is the situation, I have trajecory file of a protein of interest. That protein has 2 main cavities that are participating in interraction with ligands or other proteins and also other cavities. ...
0
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0answers
21 views

What exactly is “oxidation state”? [duplicate]

the textbooks say that it is the amount of electrons lost or gained by an atom in a bond but in a covalent molecule the atoms never technically lose electrons ,instead share them to in such a way to ...
-2
votes
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?
3
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1answer
45 views

The fifth shell of an atom [on hold]

According to the $2n^2$ rule, the fifth shell should accommodate 50 electrons. However, my chemistry book says that the $2n^2$ rule does not apply to the fifth shell. Could you explain why this ...
0
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1answer
57 views

Why does bubbling carbon dioxide through calcium hydroxide result in a precipitate?

Why does the addition of carbon dioxide to calcium hydroxide create the precipitate calcium carbonate? What happens chemically for such a molecule to form? How exactly do their interactions come into ...
2
votes
2answers
77 views

Temperature measurement

Consider some liquid in a beaker. I am measuring its temperature using a thermometer. When i put my thermometer's bulb in the liquid, the particles of the bulb gain the same kinetic energy as of the ...
0
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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 ...
0
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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 ...
-2
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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 ...
0
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3answers
41 views

Did the finding of the electron from cathode rays/ oil drop experiment at least temporarily throw Dalton's Atomic theory “out the window”? [closed]

Because chemists learned that the atom was divisible, did Dalton's theory get any criticism or did they just adjust the theory to fit the new idea?
1
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1answer
56 views

Reaction of ether with HCl

Most of the reactions undergo ring expansion whenever favourable. But this reaction [1, p. 514] doesn't seems to do so: Practice Problem 11.18 Provide a mechanism for the following reaction. ...
0
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2answers
47 views

Methanol mixed with varsol [closed]

If I have varsol in a tank and methanol is put into the same tank will methanol rise to the top or will it separate? Or will it mix together ?
1
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1answer
66 views

Why does coumarin predominantly exist in keto form?

By applying the logic that phenol exists in enol form rather than keto form as it attains aromatic character, why is it not the case in coumarin?
8
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2answers
115 views

Radiofrequency transmitter in an NMR experiment: Is there an involvement of (electromagnetic) radio wave?

A student in Chemistry StackExchange asked the effect of radio waves on matter, which led to an interesting set of arguments by some users. It was pointed out that in a proton nuclear magnetic ...
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0answers
21 views

AB4 type molecule with covalent bond

I have AB4 molecule, in which i have 4 atoms B bonded to a central atom A. Now, i know that the angle between any two bond pair electrons is 109.5°. And the bond length is also same (=x, say). Now, ...
-1
votes
1answer
31 views

Equivalent mass in case of disproportionation reaction

I came across a question where the equivalent mass of hypophosphorus acid is to be found in the given reaction: $$\ce{2H3\overset{+1}{P}O2 -> H3\overset{+5}{P}O4 + \overset{-3}{P}H3}$$ If $M$ is ...
1
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0answers
18 views

Why not create a latent heat battery?

Since latent heat is not sensible, it seems like it would be useful in creating an efficient battery. Sensible heat interferes with electron flow in standard lead-acid and other batteries. The latent ...
41
votes
1answer
6k views

What's the biggest organic molecule that could have a smell?

For a molecule to have a smell it's necessary that the molecule be volatile enough to be in the air. So I think that excludes molecules which are solid at room temperature and atmospheric pressure. ...
5
votes
2answers
281 views

How to predict the decomposition products of for example barium carbonate?

I am a high school student studying basic chemistry and I am confused about the process of writing decomposition reactions. The question I have encountered asks me to decompose $\ce{BaCO3}$. Online, ...
0
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0answers
11 views

Diferent Sacrificial Anodes Duration

Zinc, magnesium and alluminium are the common anodes, there are all diferent. Ones more reactive than the other, which is why some are more effective in salt water. Salt water is a better conductor to ...
2
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0answers
45 views

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

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 ...
-1
votes
1answer
32 views

Stereoisomerism [closed]

The C-C bond in alkanes can freely rotate , then how can you call 2 alkanes (having atleast one chiral carbon) as diastereomers if they have different arrangements of groups (atoms) in space & ...
1
vote
1answer
61 views

How is the Hessian evaluated?

I was reading about the various ways to optimise the geometry of the system, and found that none of the sources mention how the Hessian matrix is obtained. How does one obtain the Hessian matrix? I’m ...
1
vote
0answers
27 views

Four-electron integrals over GTOs

I was looking through the following presentation: http://folk.uio.no/helgaker/talks/SostrupIntegrals_10.pdf Looking at the section on 4-electron integrals, I couldn't help but notice that the slides ...
1
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0answers
27 views

Why do some compounds without carbonyl group give positive 2,4-DNPH test?

I was performing some experiments in Chemistry Lab today in which I had to find the functional groups present in a compound. It being a very basic undergraduate course introducing us to the ...
1
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0answers
13 views

Protocol during antechamber heating

I recently setup a heating apparatus for the large antechamber in my glovebox (i.e., large amounts of heating tape). Eventually, I want to do bake-outs for my moisture-sensitive chemistries (e.g., ...
1
vote
0answers
18 views

Smoky lights at events - Piped in or a chemistry reaction of some kind?

Was at Dreamhack MTL this weekend and realised that in the whole venue there seems to be just a little bit of smoke in the spotlights and other light sources. You also see that kind of smoke in shows ...
1
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0answers
23 views

Favoured position in nitration of pyrrole [duplicate]

I try to figure out the preferred position of nitration (determine whether compound A or B is the major product) by looking at the resonance structures of the intermediate cation. The solution then ...
1
vote
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 ...
0
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1answer
63 views

Why is it ill advised to eat the solid aspirine formed from salicylic acid + acetic anhydride

In the laboratory notes it is indicated that it is ill advised to eat the solid formed from this experiment. An esterification reaction, in which salicylic acid is treated with acetic anhydride. If ...
1
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0answers
37 views

Number of states of phase space of a particle under Heisenberg certainty

In classical mechanics, the state of a motion can be determined by its position r and momentum p. One-dimensional motion of a particle that can be described by a trajectory in the plane that has $x$ ...
1
vote
1answer
26 views

Collision that governs kinetic model of gas [closed]

From Atkins' Physical Chemistry 10th, it states that The kinetic model is based on three assumptions: The gas consists of molecules of mass $m$ in ceaseless random motion obeying the laws ...

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