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13 views

Density and partial pressure

A sample of $\ce{NOBr}$ gas was placed in a rigid flask where it decomposes at $\pu{25 ^\circ C}$ according to the following reaction: $$\ce{2NOBr(g) <=> 2NO(g) + Br2(g)}$$ At equilibrium, the ...
-2
votes
0answers
18 views

Which of the following is chiral as well as dissymmetric

In an examination, I came across a question, 'which of the following is chiral as well as dissymmetric'. There were four options, and among them, two were achiral, and had improper axis of symmetry. ...
2
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0answers
16 views

Why do alkenes (olefins) burn hotter than alkanes (paraffins), even though alkanes are denser and more hydrogen-rich?

Burning hydrogen releases more total energy than combusting carbon, and all alkanes are denser as well, so why are flame temperatures for alkene molecules higher than their equivalent alkanes? P.S.: ...
0
votes
1answer
33 views

Molar mass question

Molar mass of oxygen is 16g/mol , but O2 is 32g/mol , it is shows that 32 gram per 1 mol ,but if we add 1 mol oxygen and one mol of oxygen , shouldn't it be 32 gram per 2 mol for dioxygen ? it doesn't ...
-1
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0answers
21 views

Why does P vs V graph obtained by Boyle deviate from the real gas [duplicate]

My book contains the following graph. My book says - "Deviation from ideal behaviour also becomes apparent when pressure vs volume plot is drawn. The pressure us volume plot of experimental data (...
-2
votes
0answers
20 views

Rate equation derivation for photocatalytic h2 producing reaction [closed]

I have a photocatalytic H2 producing reaction where methanol and water is reacted with sunlight and catalyst to give H2. when I develop rate equation I take water concentration as 1. Is it correct and ...
-1
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0answers
18 views

How do I model drug diffusion from polymeric matrix?

My problem consists of a structure (say a cylinder) made from a homogenous distribution of a drug from a polymeric matrix. These compounds are mixed homogeneously in different concentrations (10% drug ...
-1
votes
0answers
20 views

baking soda + skin => soap? [closed]

From here https://www.sumnerhealthcentre.com/site/drug-free/soap Soap is very good at what it does - removing oily residue from the skin. It is very difficult to remove motor oil or any greasy ...
2
votes
1answer
212 views

Why does polymerisation of n glycine molecules give n water molecules?

Referring to this webpage, Condensation polymerisation of glycine A simple counting argument would tell us that: 2 glycine molecules react, releasing 1 water molecule 3 glycine molecules react, ...
-3
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0answers
25 views

how come Oxygen on the 2nd structure won't have +1 charge [closed]

how come Oxygen on the 2nd structure won't have +1 charge because if you use formal charge formula it 6-5 = +1
-1
votes
1answer
57 views

What is the difference between structure and morphology in polymer blends?

When talking about polymer blends there is a difference between its structure and morphology, but I am not sure what it is. These two terms are used interchangeably in materials I use to study, but I ...
-1
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0answers
33 views

what is the procedure for preparing the sample 3-(2-furyl) propionic acid? [closed]

vibrational analysis of the sample for this project work, iam analyzing the vibrational modes of this sample using raman spectrometer. so i need to know how to prepare this sample
3
votes
2answers
72 views

Identifying radial probability distribution curve given $n$ and $l$ value

The correct radial probability distribution curve for the hydrogen atomic orbital with principal quantum number,$ n = 3$ and azimuthal quantum number, $l = 1$ is: ($4πr^2ψ^2 $= radial probability ...
-3
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0answers
13 views

Find no. of molecule of NaCl in Acid-base Reaction? [closed]

Na2CO3(a.q) + 2HCL(a.q) --> 2NaCl(a.q) + CO2(a.g) + H2O(l) If this reaction is carried out by mixing 2.12g of ...
0
votes
0answers
24 views

Hydroboration-Oxidation of Alkynes to form Ketones [closed]

Hydroboration-Oxidation adds a hydroxyl group to alkynes to forn enol. The enol tautomerises to form aldehyde or ketone. In case of non-terminal alkynes, two ketones are formed. Here is the example ...
-4
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0answers
46 views

Why do lead acid batteries corrode? [closed]

As far as I know, an increase in temperature speeds up the cell chemical reaction, which speeds up the electrolyte evaporation, which increases the release of hydrogen gas, and hydrogen is the ...
2
votes
0answers
42 views

Good sample references for TGA, DSC and DTA thermal analysis

I am trying to estimate kinetic parameters for my liquid decomposition using thermal analysis. After doing a literature survey, I have decided to use the following - thermogravimetry (TGA) ...
0
votes
2answers
31 views

Change in entropy in reversible and irreversible processes

The change in entropy for a reversible process is given as- $\Delta$S = $\frac{q_{rev}}{T}$ Where qrev is the heat supplied isothermally and reversibly. The change in entropy for a irreversible ...
0
votes
1answer
19 views

Expansion of a gas under isothermal and reversible conditions

What is the reason for the statement - "When the expansion of an ideal gas is carried out under isothermal and reversible conditions, the internal energy does not change, i.e., $\Delta$U=0?" ...
3
votes
1answer
72 views

Why is the term “nascent nitrogen” still used in metallurgical industries?

Continuation of Why do nitrogen-containing organic compounds give N2 as the combustion product? (comment converted into question) Nascent state is an obsolete theory in chemistry and is discredited. ...
0
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0answers
40 views

Which oxygen in ester group is more nucleophilic?

According to my understanding, the filled orbital (lone pair electron for this) is more nucleophilic (higher energy) if: it has more $\mathrm p$ character (since p orbital is the furthest from the ...
2
votes
1answer
47 views

Regarding the oxidation of Manganese(II) ion by Peroxodisulphate ion

The following information is mentioned in my textbook: In the laboratory, a manganese(II) ion salt is oxidized by peroxodisulphate to permanganate. $\ce{2Mn^2+ + 5S_2O_8^2- + 8H2O -> 2MnO4- + ...
2
votes
0answers
21 views

Difference between nucleophilicity of phenoxide ion and acetate anion in protic/aprotic solvent

As far as I could think, the phenoxide ion is comparatively larger as compared to acetate ion, so it should undergo less solvation in presence of a protic solvent and thus its nucleophilicty should be ...
3
votes
1answer
57 views

What is the mechanism of temporary bleaching of flowers by SO2 ? Can H2S be used?

There are many claims on the web, explaining that the bleach action of Chlorine gas in discoloring of flower proceeds as follow and require moisture for it : $$\ce{ Cl2 + H2O <=> HOCl + HCl <=...
0
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0answers
24 views

What's the “Charge” in Steric Number Formula

I was reading about the Steric Number Formula here. There, I came to know that the Steric Number $N=\frac{V+M \pm I}{2}$ where $V = n(\ce{e-})$, the number of valence electrons of central atom, which ...
1
vote
0answers
12 views

Why does increasing subshell cause ionization energy to decrease?

I know that increasing subshell decreases ionization energy; for example, going from Beryllium to Boron. I do not understand why this is. The answer my textbook (Chemistry 2e on OpenStax) gives is ...
0
votes
1answer
33 views

How would you test for ppm of lead in a powder?

Looking to test the ppm for lead in a powder that is a food item. No experience in chemistry. Possibly may need to test for other heavy metals.
3
votes
1answer
67 views

Friedel–Crafts acylation of substituted anisole

I am attempting to form a synthetic route to a tetrasubstituted benzene compound. In the scheme, there is a step that requires the formation of a carbon–carbon bond in the C-6 position of a methoxy ...
-1
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0answers
33 views

How do we draw the Lewis structures of complex molecules and ions? [closed]

How do we draw the Lewis structures of complex molecules and ions such as ClOF3, OSF4-, F2SeO2, etcetera? I know that for simpler molecules, we can determine the central atom using lowest ...
-4
votes
0answers
19 views

Enthalpy change in an isothermal process at constant pressure [closed]

While studying thermodynamics I encountered a statement stating that " The Enthalpy change in an isothermal process is zero".I started analysing and got stuck when I came to the condition ...
-1
votes
0answers
44 views

How do chiral molecules actually rotate light? [duplicate]

How do molecules actually change the direction of a photon of light? It requires more of a particle physics answer but the question is highly relevant for chemistry.
1
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0answers
14 views

How to extract transition density cube from .fch file in Gaussian? [migrated]

I have been trying to extract the transition density cube of a simple molecule, $H_2O$. I did a regular geometry optimization and then TD-DFT calculation with a keyword Density=Transition=1, which is ...
-1
votes
1answer
18 views

Why do we use external pressure to calculate work done by a gas in case of compression instead of using internal pressure?

According to formula work done is (Resisting pressure X dV)? Then in case of compression, isn't the resisting force is internal Pressure? Then why we the formula for compression is same as expansion ...
-2
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0answers
58 views

How to produce light of wavelength range 95nm to 100nm on large scale and if there is one in market then please send the link [closed]

i need light of wavelength ranging between 95nm to 100nm to perform an experiment on selective ionization of gas mixture and for this technique to be used at large scale i want to know about how to ...
2
votes
1answer
46 views

Relation between standard silver-silver chloride electrode potential and solubility product of silver chloride

I learned that $E^\circ_\ce{Cl^-|Ag,AgCl}, E^\circ_\ce{Ag^+|Ag}$ and $K_\mathrm{sp}$ of $\ce{AgCl}$ are related as $$\boxed{E^\circ_\ce{Cl^-|Ag,AgCl} = E^\circ_\ce{Ag^+|Ag} + \frac{RT}{F}\ln K_\mathrm{...
2
votes
0answers
31 views

Different products with varying aluminium chloride concentration in a reaction of propiophenone

How does the product change with varying $\ce{AlCl3}$ concentration? Answer: In excess, meta bromination is observed and if not, then alpha hydrogen is substituted by ketone halogenation mechanism I ...
0
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0answers
46 views

Confusion in D/L nomenclature [duplicate]

With regard to carbohydrates, it is known that in a Fischer projection, if the $-OH$ group is on the right side of the lowest priority asymmetrical (chiral) carbon, then we name it as D and if it is ...
5
votes
1answer
414 views

How much CO2 is produced when burning 1GJ of Natural Gas

Background I am trying to determine how many kg of $\ce{CO2}$ are released when burning 1 GJ of natural gas. What I've tried I have very little chemistry knowledge, but google led me to these two ...
5
votes
2answers
2k views

Which is a more accurate scale for a chemistry high school lab - a triple beam balance or a digital balance and why?

I would like to ask the experts of this chemistry community their opinions on which balance is more accurate and effective to use in a high school chemistry lab- a triple beam balance or a digital ...
7
votes
3answers
392 views

Choosing reaction stoichiometry in organic synthesis

Reading papers about organic synthesis, I see many cases like setting one material as 1.2 eq. I presume that reagents used more than 1 equiv are relatively inexpensive or less reactive than other ...
-1
votes
0answers
36 views

What container can i use to safely store isopropanol at 99.8%? [closed]

I finally get Isopropanol at 99.8% for cleaning purposes of electronics and plastics and my idea is to have various bottles, some with only Isopropanol and other mixed with distilled water What can i ...
-1
votes
0answers
31 views

The oxygen in hydronium has a pair of non-bonding electrons in its valence orbital. Would it be possible to bind one more proton (H+) to hydronium? [duplicate]

Hydronium oxygen has a pair of non-bonding electrons in its valence orbital. Chemically it would be possible to bind one more proton ($\ce{H+}$) to the hydronium and thus form the $\ce{H4O_x}$ cation....
-1
votes
0answers
11 views

What's the difference between Heat of Formation and Bond Enthalpies? [closed]

I don't quite understand the concepts of Heat of Formation and Bond Enthalpies, and why their respective formulas work, it would be really great if someone could please help explain the difference/...
-4
votes
0answers
19 views

How many electrons and protons are there in the sum of the hydronium atoms? (Homework) [closed]

Hydronium H₃O+ Hydrogen*3 3 Protons 3 Eletrons Oxygen 8 Protons 8 Eletrons -1 = 7 7+3= 10 Eletrons 8+3= 11 Protons Is correct ?
-4
votes
0answers
22 views

why BF3OEt2 use is additive with TIPSOTf or TBSOTf [closed]

why BF3OEt2 use is additive with TIPSOTf or TBSOTf in aldol type acetal addition reaction
-4
votes
0answers
24 views

Do the covalent bonds in water molecules promote hydrogen bonding between water and other molecules? [closed]

I think the question title is pretty self-explanatory but I was wondering if the covalent bonds in water promote hydrogen bonding between water and other molecules and whether they promote polar ...
2
votes
1answer
64 views

Some salts lower the vapour pressure of water - do any raise it?

Plain old NaCl salt can slightly lower the vapour pressure of water for a given temperature. Other salts such as CaCl₂ lower the vapour pressure to a larger degree. Do any salts, or compounds of any ...
-3
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0answers
29 views

Instant ice or freezing capabilities [closed]

What chemicals when mixed or added to water can create ice, or reduce surrounding temperature greatly?
1
vote
0answers
52 views

The ways to determine if an ionic compound is paramagnetic or not

Find which of $\ce{Na2O2}$ and $\ce{CsO2}$ is paramagnetic. (Adapted from JEE advanced paper-1 2016, q.22) The given solution involves removing the cations and taking the anionic part, i.e. $\ce{O2^2-...
0
votes
0answers
41 views

Corrosive potential of molten ionic salt

I was looking at this video about fourth generation of nuclear reactors and one of developing concepts is molten salt reactor (MSR) where melted ionic salt replaces water as coolant and also acts as a ...

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