All Questions

-1
votes
0answers
18 views

What is the colour of hexaamminechromium(3)? [closed]

What is the colour of hexaamminechromium(3) when we add extra Ammonium hydroxide to Chromium Hydroxide?
-3
votes
0answers
28 views

Charge phone using simple voltaic cell [closed]

Can i charge my phone using voltaic.cell and. How because i have cut the usb wire and found 4 wire in it which is red,black,green,white which one is connected to mg and which one is connect to copper
0
votes
0answers
20 views

Terpene cyclization on terretonin biosynthesis

I would like to ask about a terpenoid cyclization in terretonin biosynthesis in a research paper authored by Matsuda et al., Curr. Opin. Chem. Biol. 31, 2016. It is showed in the paper that The ...
0
votes
0answers
18 views

Coordination number of complex resulting from sodium nitroprusside test

In my textbook the following reaction is given to identify sulphide ion : Na2[Fe(CN)5(NO)] + Na2S --> Na4[Fe(CN)5NOS] (violet solution) Here's what I want to know : Is NOS a newly formed ligand? If ...
3
votes
3answers
86 views

What defines a discharged battery?

In the case of an AA Alkaline battery, what actually happens inside the battery once it is fully discharged? What components of the battery change as we use it?
2
votes
1answer
48 views

Proving a relation for fugacity of component i in term of independent variables (T,V)

In Molecular Thermodynamics of fluid phase equilibria by Prausnitz et al. [1] the authors recommend to use the following equation which gives the fugacity of component $i$ in terms of independent ...
6
votes
0answers
63 views

Mechanism for Friedel-Crafts Acylation in Synthesis of Sertraline

In the first step of the synthesis of Sertraline, aluminium chloride catalyst was used in a Friedel-Craft's reaction to give the following product. My question is how does the exact mechanism work? 1-...
0
votes
0answers
43 views

Where does copper form?

I thought zn and cu both lose 2e- to pt but someone is telling me it's wrong]
4
votes
1answer
80 views

Redox Combustion Reactions

Consider a combustion reaction like the complete combustion of ethane. Here is what I have for the complete combustion as well as the oxidation and reduction: $$\ce{\overset{-3}{C}_2\overset{+1}{H}_6 ...
-5
votes
0answers
23 views

Mass Percentage [closed]

An aqueous solution of iron(II) chloride contains 5.02 grams of iron(II) chloride and 17.3 grams of water. What is the percentage of iron(II) chloride by mass in the solution?
0
votes
1answer
27 views

Obtaining atomic form factor from electron density?

I know that atomic form factors for x-ray scattering are obtained by Fourier transform of the electronic charge density. I am looking for a citable elementary source (book, review, article) which ...
1
vote
2answers
50 views

How can we tell if an ion is amphiprotic [closed]

If I had the following ions: $$\ce{HCO3^-}$$ $$\ce{H2PO4^-}$$ $$\ce{CH3COO^-}$$ Which ones would be amphiprotic? Looking at my $ K_A$ chart, it looks like each ion is formed by the disassociation of ...
-2
votes
0answers
21 views

amino acid titration [closed]

Suppose an aa (HA) has one ionizable group, and the pKa of this group is 5.0. If one has 100 mL of a 0.1 M solution of this compound at an initial pH = 7.0, what is the final pH after 20 mL of 0.1 M ...
4
votes
0answers
39 views

Why do old black and white photos fade?

I understand why photos based on organic dyes would fade (discussed previously). But photos based on metallic silver fade as well such as like the one shown below. As a metal (a fairly stable one at ...
1
vote
1answer
63 views

How do I calculate the hydronium ion concentration if I know the strontium hydroxide concentration?

This is my first question so I would appreciate feedback on how to ask better questions. Forgive me if I don't know how to properly format math/chem. The guide is confusing. I was taking a practice ...
1
vote
0answers
17 views

Determination of pKa and molar absorptivity coefficient using spectrophotometry [closed]

An indicator BPB (Brophenol Blue) is used and dissolved in solutions of various known $\mathrm{pH}$. Then, the absorbance of each solution at 590 nm was measured and the question asks for molar ...
3
votes
1answer
61 views

How to programmatically identify a chemical compound in my program?

I have a small set (a hundred of items) of chemical compounds in XYZ formats in my DB. How to quickly identify that a given chemical is or isn't in this DB? I don't want to just scan through them, or ...
0
votes
1answer
36 views

Orbital size of Carbon and Oxygen in Methanal

I was given an introductory question into Carbonyl chemistry today and I wanted to ask a question about Methanal. The following picture was shown below of Methanal: and I noted that the orbital ...
3
votes
0answers
43 views

Jacobi coordinates - definition

I became quite confused about Jacobi coordinates. Until now I've been used to them as the coordinate system, where coordinates are vectors pointing to the center of mass of previous "subsystem", as we ...
1
vote
0answers
25 views

Exception in trend of increasing ionisation energy across a period

One exception to the trend of increasing ionisation energy across a period in e.g. period 2 is going from N to O. There is no loss of exchange energy in I1 of O, but there is 2K lost in I1 of N, hence ...
-4
votes
1answer
35 views

A question in stiochiometry [closed]

How many moles of $\ce{NH3}$ are there in $\pu{90 L}$ of it at STP? $4$ $32\times 10^{23} $ $23$ $3.2$ Please explain your answer as much as possible.
5
votes
0answers
64 views

Contribution of vibrational degrees of freedom

The ratio $\frac{\mathrm{C_p}}{\mathrm{C_v}}$ for linear triatomic molecules including vibration contribution is given by: ? Attempt: We are aware that $C_v = \frac{fR}{2}$ and $C_p = C_v+ R$ ...
1
vote
0answers
34 views

Definition of ionisation energy

My lecturer has defined ionization energy or ionization potential of a species A as the molar internal energy change, ΔU, for the reaction: $\ce{A (g) -> A+ (g) + e-}$ at $\pu{0 K}$, with reactants ...
0
votes
0answers
22 views

SpectroVis spectrophotometer values changing after pulling cuvette out

I am required to write a research paper for school in a specific subject and I have chosen to write mine in chemistry. I am investigating the kinetics of the Briggs-Rauscher oscillating reaction. I am ...
-1
votes
0answers
14 views

Why ritz combination principle is not accurate for all elements? [closed]

Why ritz combination principle is not accurate for
-1
votes
1answer
27 views

Table for magnetic moments for all elements in periodic table? [on hold]

I'm trying to look for a table for magnetic moments for all elements of the periodic table for my research project in computational chemistry, can anyone direct me to a suitable one?
0
votes
1answer
47 views

Point group from mono to bulk MoS2

Many articles say even numbers of layers or bulk crystal MoS2 have D6h point group and odd numbers of layers (including monolayer) MoS2 have D3h point group But whenever looking at the figure of ...
-2
votes
0answers
42 views

Convergence failure [on hold]

I trying to run a DFT calculation with the following job input: aui2s2pc20h18 0 1 # PBEPBE/LANL2DZ Opt Freq NoSymm aui2s2pc20h18 0 1 Au 2.9788534146 ...
0
votes
0answers
27 views

Finding the n-factor of C₂O₄²⁻

In the reaction $\ce{C2O4^2- → CO2}$ the $n$-factor of $\ce{C2O4^2-}$ is: So I think the answer to this question is $2$ because in $\ce{C2O4^2-}$ the oxidation number of carbon is $+3$ and in $\ce{...
-1
votes
1answer
34 views

Do all reactants have appear in the first mechanism of the rate law?

I have the following reaction, $$\ce{CO + NO2 -> CO2 +NO}$$ The "second" mechanism is given: $$\ce{NO3 + CO -> NO2 + CO2}$$ So when searching for the first mechanism, I found this one to work: ...
0
votes
1answer
26 views

Why is the major product of the reaction of 1-naphtol with benzene diazonium chloride not the ortho product?

If 1-napthol reacts with benzene diazonium chloride, it gives the para product with respect to the hydroxyl group. However, shouldn't the major product be the ortho one, because there will be ...
3
votes
2answers
155 views

Mechanism of ring formation of an epoxide under acidic aqueous conditions

I am trying to figure out the mechanism of this reaction: I think the $\ce{H+}$ will first attack the oxygen of the epoxide and another $\ce{OH-}$ will be added to the most substituted carbocation, ...
-1
votes
1answer
27 views

Carbonic acid, bicarbonate in water [closed]

When you add CO2 into water, carbonic acid is created. From carbonic acid (H2CO3), HCO3 + H is formed. When CO2, and H2CO3 leave the water, does HCO3 leave as well, often measure as kH, carbonate ...
0
votes
0answers
25 views

Adding apple cider vinegar to a solid DIY deodorant

If I wanted to add a bit of apple cider vinegar to my oil based deodorant, to increase antimicrobial properties, would this cause me to need a preservative? My deodorant is not water based, so I don't ...
0
votes
1answer
32 views

How can one distinguish an IR spectroscopy alcohol band on an organic molecule versus the alcohol bands from water in the sample?

I'm reading this IR spectra and trying to determine if the large broad band at 3388 is alcohol from an intermediate or from water in the sample. The details of the reaction, conditions, and mechanism ...
2
votes
1answer
44 views

Can you lower the alcohol concentration of a drink using vegetable oils?

The log POW of ethanol is −0.18 according to Wikipedia, i.e. in a two-phase system ethanol would preferrably accumulate in the aqueous phase, but not by much. Suppose I wanted to lower the alcohol ...
-3
votes
0answers
20 views

How can I make 2M of sodium hydroxide solution from 25g of sodium hydroxide pellet? [closed]

I have 25 grams of sodium hydroxide pellet. I want to prepare 2M of sodium hydroxide solution. How do I go about it, please?
0
votes
1answer
46 views

Maximum number of atoms in the ground state

I was given the following question. A sample contains $100$ identical and hypothetical $H$-like atoms ( $Z$ may be fractional). Out of the given atoms, some are in the ground state, while others ...
-3
votes
0answers
16 views

Coordination compounds ean rule [closed]

Which complex follow the sidgwick rule Ean rule where M =24?
-3
votes
0answers
40 views

when water and alcohol are mixed, why don't the boiling points change? [closed]

when water and alcohol are mixed, why doesn't the boiling points change? The vapor pressure should increase so the atmospheric pressure will equal to the vapor pressure faster, how do alcohol and ...
-2
votes
0answers
19 views

Thermal conductivity of materials [closed]

Why does having delocalised electrons increase a materials thermal conductivity?
-3
votes
0answers
25 views
-2
votes
0answers
19 views

Reaction of metals during electrolysis? [closed]

I am currently looking into what metals can be used for electrolysis....more specifically to split hydrogen from oxygen ....im curious as to what I may use metal wise that won't leave contaminants in ...
-3
votes
0answers
26 views

Will a nail in a bottle rust without water being in the bottle? [closed]

Will a nail rust if it is in a bottle without water? Any help is appreciated as this is for a school project.
-8
votes
0answers
37 views

Is Organic Chemistry Neccessary in the Med field [closed]

Is it necessary that one who wishes to go into the Medical field must study Organic Chemistry.
2
votes
2answers
51 views

MO diagram of BeH₂

I was learning about the MO diagrams of triatomic molecules and was left slightly confused about $\ce{BeH2}$. A picture of the MO is shown below: When looking at the $\mathrm{1s}$ combinations, I ...
0
votes
0answers
29 views

Derivation of mass flow rate and mean velocity [closed]

How do you derive the expressions for the mass flow rate, $\ce{w = 2bWρ<u>}$, and the mean velocity for the schematic below? How do you get the momentum balance: $\ce{WΔx(ρu^2(x) + p_1) + LW\...
3
votes
2answers
65 views

Scientific Reason for Salt Solution Gaining Volume

A little background to this question: my mom placed a glass with salt and enough water to just cover the salt in a room to "absorb negative energy" out of the room at her office. It obviously "worked"....
0
votes
0answers
46 views

Why charged canonical structures of phenanthracene are not taken into account? [closed]

In the process of delocalization of pi electrons they do not directly jump between atoms instead it first finds place on a carbon or something else but why it is not in phenanthracene or any other ...
1
vote
0answers
18 views

Using Wilkinson's Catalyst to reduce esters?

I was solving some questions on alcohols when I came upon a question in which it was asked that whether esters can be reduced using hydrogen in the prescence of wilkinson's catalyst. Now I know that ...

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