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26 views

Reaction of ethene with another double bond in presence of hv [closed]

First step i understand is syn addition of H but what is A + ethene in presence of hv giving?
0
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1answer
26 views

Rate determining step for parallel reaction?

I have always read that the rate determining step is the slowest step in a reaction (source: Wikipedia). In chemical kinetics, the overall rate of a reaction is often approximately determined by ...
4
votes
2answers
555 views

What does it mean to 'fuse' ores? [closed]

For the extraction of chromium, fusion of chromite ore with sodium or potassium carbonate in excess of air is done. What exactly happens in this 'fusion' process? source : ncert chemistry class 12 ...
2
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0answers
21 views

Order of Reaction differs in equation and linearisation

I have given the following equation: $A + 2B \rightarrow C$ $ v = –k\cdot [A]\cdot[B]^2$ gives me the orders 1 for A and 2 for B. That results in a total order of the reaction of 3. So far so good. ...
4
votes
2answers
129 views

Why Zn has highest ionisation enthalpy in 3d series?

Zn which has the highest ionisation enthalpy in 3d series.The reason given in my textbook is: The value of zinc is higher because it represent ionisation from 4s level. This is not correct because ...
3
votes
1answer
101 views

Reorganization during ionisation for d block elements

This is a quote from my textbook: The irregular trend in the first ionisation enthalpy of 3d lmetals,can be accounted for by considering that the removal of one electron alters the relative ...
-1
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0answers
11 views

How is the enthalpy change of reaction, and neutralisation found [closed]

! This is question 1! This is the question 2! This is the answer for question 2 Hi, I am struggling to understand what I am calculating with I do my value for q (calculated from q=mcdeltaT) ...
0
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3answers
63 views

Reaction of Fe2+ and S2- to form FeS

Consider this reaction: $$\ce{Fe^{2+} (aq) + S^{2-} (aq) <=> FeS (s)}$$ The equilibrium constant for the reaction is $1.6 \times 10^{17}$ at $\pu{298K}$. If equal volumes of $\pu{0.06 M}$ ...
-2
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0answers
39 views

Proton vs Electron forces [duplicate]

I understand that protons (positive) and electrons (negative) are attracted to each other through electrostatic forces. I also understand that as you go across a period, the more protons you add to ...
1
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2answers
66 views

What happens to the crystal structure of ice as it gets colder and colder [duplicate]

Not sure if this belongs on Chemistry or Physics stackexcahnge. As water freezes into ice, it turns into a solid, and expands as it forms a crystal structure. But what happens to this crystal ...
-2
votes
1answer
38 views

If I dissolve 0.1M of CaCl2.2H2O in water, do I get a 0.1M CaCl2 solution? [closed]

If I dissolve $\pu{0.1 M}$ of $\ce{CaCl2.2H2O}$ in water, do I get a $\pu{0.1 M}$ $\ce{CaCl2}$ solution?
1
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0answers
24 views

Electrical conductivity and the limits of Kohlrausch's law

I am currently writing a lab report on electrical conductance and I realized that my partner prepared $\pu{0.1 M}$ solution instead of $\pu{0.01 M}$. Now, I am supposed to find the molar conductivity ...
2
votes
1answer
35 views

Shielding effects and atomic size [closed]

The atomic size on going from aluminum to gallium decreases because of poor shielding effect of the $(n-1)d$ electrons, but on going from copper to zinc, the size increases due to the same shielding ...
1
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0answers
46 views

Boat Conformer of Cyclohexane Stable?

It is well-known that the "chair" conformation of cyclohexane is the most stable of it's conformers. But is there any cyclohexane derivative where the other notable conformers (boat, half-chair) are ...
0
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0answers
53 views

Does an aryl compound with any functional group attached to it, undergo benzylic oxidation? [duplicate]

> If you look at this compound, only the benzylic carbon on the top has a hydrogen attached to it, so how do we oxidize only the top part without touching the lower one (not sure if this product is ...
-3
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2answers
51 views

Proof for Arrhenius equation [closed]

The Arrhenius equation states that: $$k=A\mathrm e^{\frac{-E_\mathrm a}{R T}}$$ What is the mathematical proof for this equation?
1
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2answers
58 views

How are reaction enthalpy and entropy affected by temperature

The equation for Gibbs Free Energy demonstrates how the standard change in Gibbs Free Energy for a reaction is affected by temperature. $$\Delta G^\circ = \Delta H^\circ - T\,\Delta S^\circ$$ ...
1
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0answers
36 views

Liquid neon freezer?

Liquid nitrogen is approximately -330 degrees Fahrenheit. Liquid neon is approximately -413 degrees Fahrenheit. I want to know about if this type of freezer is easily possible in practice and if such ...
1
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0answers
13 views

Find drugs that have a particular solvent in a database [closed]

Is there a database where I can filter drugs for animal/human use by what ingredients/solvents they have? I'm specifically looking for all the drugs with a specific solvent/chemical compound.
1
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0answers
36 views

Calculating the energy of a molecule using probability distributions

I wish to calculate the energy for a protein where the position of all the C-alpha atoms is known. One way is to calculate the pairwise distances between the atoms and then look up a probability ...
6
votes
1answer
59 views

How to predict disproportionation products from Frost diagram?

I read that concave points in a Frost diagram disproportionate. But what are the products of the disproportionation? For example, in the Frost diagram for manganese at pH = 0, the species $\ce{HMnO4-}...
-2
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1answer
27 views

Salinity difference in KCl and NaCl

If I calibrate my conductivity probe using KCl calibration solution, then test my aquarium water which is NaCl, will I get a false reading? When I use a digital refractometer calibrated to zero using ...
0
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0answers
26 views

Help to understand the fundamental equation of thermodynamics

The fundamental equation of thermodynamics states that $dG = VdP-SdT$. I am having difficulty understanding this equation. The Wikipedia page for Gibbs free energy says: ... is a thermodynamic ...
1
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1answer
37 views

Chemical Reaction for making Acetic Acid from Glycerol inside Fermenter

I have been trying to find a chemical reaction for the formation of acetic acid from glycerol. I have been searching different literature, but apparently the reaction can not be found. I was hoping ...
3
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0answers
39 views

Why does Larmor precession occur in NMR?

Larmor precession is the phenomenon that in NMR the spin (and by default also the magnetic dipole moment) of protons does not line up with the applied magnetic field but rather precesses around this ...
2
votes
2answers
29 views

How does the rate constant change with the change of the temperature?

In class, we discussed the following multiple-choice question. The rate expression for a reaction is: $$rate = k[X][Y]$$ Which statement is correct? A. As the temperature increases, the ...
0
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2answers
45 views

What is electrolytic protection?

My highschool textbook tells me that sacrificial protection (more technically-cathodic protection) and electrolytic protection are different. I have searched high and low for an explanation of ...
3
votes
1answer
66 views

Computing the bond spring constant from first principles

Given a set of atoms and their positions in space, is there a way to compute the bond spring constant for each pair of atoms that are considered to be bonded (I can already determine the bonds with ...
-1
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0answers
28 views

Does the concentration of a solution change when you add another solution to it? [closed]

Let’s say if I wanted to create a buffer. This buffer would consist of HF(aq) and it’s conjugate base, F-(aq). If I were to use 0.1 M HF and 0.28 M F- and add them to each other, would the ...
0
votes
1answer
57 views

Why is the HOMO-LUMO gap in N2 and CO of different sizes? [closed]

Why is the HOMO-LUMO gap in $\ce{N2}$ and $\ce{CO}$ different even though they have the same number of valence electrons?
1
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0answers
36 views

What is the chemical equation for a Maillard reaction? [closed]

I'm a 10th-grader in my first year of chemistry. We have an assignment to make a brochure about a certain reaction, and I'm studying Maillard reactions. Does anyone know the chemical equation ...
1
vote
2answers
101 views

Is there any kind of reaction with two types of reactants (gases) and one product (also gas) such that the total volume after the reaction increases?

I would like to think of the following equation: $$\ce{aA(g) + bB(g) -> cC(g)}$$ where $a + b < c$ and $\ce{A},$ $\ce{B}$ and $\ce{C}$ are different gases. Is there such chemical reaction?
0
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0answers
23 views

When exactly does the first drop of distillate appear in a distillation?

The below image (source: here) is from a fractional distillation of a mixture of two liquids, one with a boiling point of 69 degrees celsius and the other with a boiling point of 98 degrees celsius. ...
1
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1answer
36 views

Formating a chemical equation - Physical states

I study chemistry in an University and I have two professors that says opposing things. One says that the physical state must be subscribed (1 at the picture) and other that it must be written to the ...
0
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0answers
19 views

Liquid fertilizer nutrient values - % weight by weight or % weight by volume?

I was convinced that liquid fertilizer labeling use the % weight by volume convention. However now I bought a magnesium-sulfur based additive. The label clearly uses % weight by weight. Weight by ...
-1
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2answers
52 views

How are CH3COOH molecules ionisied into H+ and CH3OO- [closed]

It's written in my chemistry book ,under weak acids, that the molecules of organic acids are partially ionised in water into ions. But I don't understand how molecules are ionised. I'm an ol ...
1
vote
2answers
81 views

Why is H⁺ ion considered the source of acidity, and OH⁻ considered the source of basicity? [closed]

As the title implies, what caused the association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and basicity?
-1
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0answers
18 views

Why is there a dip in the graph of Melting point Vs Atomic no between Cr Mn, Mo Tc, W Re [duplicate]

So i know that the since Cr have maximum unpaired electron in the 1st d series so maximum bond strength so highest m.p but why is there a big drop because Mn also have 5 unpaired electron which gives ...
-1
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0answers
36 views

why is 4s subshell less enrgetic than 3d? [duplicate]

General rule is that as we move away from the nucleus of the atom the energy of the shells increases but then why 4s is less energetic than 3d although 4s is at more distance from the nucleus than 3d.
-2
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1answer
68 views

What is the essential difference between distilled water of different distillation levels? [closed]

Although not a chemist I often read that different liquids made of molecules with enough low molecular weight and enough strong chemical bonds can be distilled by this process: The liquid (say, water)...
1
vote
1answer
43 views

Fehling's solution turning yellow and then black?

While testing for formaldehyde (an aldehyde), I added Fehling's solution to the sample and let the test tube simmer in a water bath for some time. I returned ~15 minutes later to see a black/dark grey ...
0
votes
1answer
49 views

Is terylene a copolymer?

Terylene is a polyester made from terephthallic acid and ethylene glycol. Even though we use two reagents, they undergo esterification to give bis(2-hydroxyethyl) terephthalate (monomer) which then ...
-1
votes
3answers
57 views

What is Rinman's green used for? [closed]

I can't find any info about it's uses neither in book nor in internet. Any help would be appreciated.
-2
votes
1answer
39 views

Options to keep someone awake against their will? [closed]

I already asked this on Worldbuilding Stack, but they told me to ask here. It is for a RPG campaign. Are there any options that an evil person could use to keep someone awake against their will? Like ...
2
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0answers
63 views

Estimating maximum size of magnetite particles in this Nile Red ferrofluid video?

In the Nile Red video Making ferrofluid from scratch a suspension of small magnetite ($\ce{Fe^{2+}Fe_2^{3+}O_4^{2−}}$) particles is produced from a combination of ferrous chloride and ferric chloride. ...
-3
votes
2answers
103 views

Gold refining using HCl

I am trying to dissolve base metals off of gold plated electronic scrap, and I am using HCl to dissolve some of the base metals. I pored in the HCl into a flask containing the scrap ( the contents of ...
3
votes
1answer
98 views

Using osmotic pressure to find the molar mass of a compound

Working on-board a research vessel somewhere at sea, you have (carefully) isolated 12.5 micrograms $(\pu{12.5E-6 g})$ of what you hope is pure saxitoxin (a non-electrolyte) from a poisonous (and quite ...
2
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0answers
49 views

What are common solvent removal methods?

In a laboratory setting, the most common solvent removal method is rotary vacuum distillation. This is something I have performed many times, starting in organic chemistry labs. However, I am ...
-1
votes
0answers
26 views

Is it possible to use ethyl acetate to extract fat using a Soxhlet?

I am wondering if it is possible to use ethyl acetate as a solvent for extracting fat from a compound using Soxhlet. Correct me if I’m wrong, but I shouldn’t the solvent be non-polar to dissolve fat,...
0
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0answers
19 views

Would Zirconium (IV) Silicate be stable in a hot oxygen atmosphere?

As per the title, really. I potentially need to protect a bit of pipework from hot oxygen (800-1000 K), and I've seen this refractory paint for sale. It says it's good up to 1750 C, but hot oxygen is ...

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