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3
votes
1answer
37 views

How to account for dilution in the sample solution when reading calibration standards?

I have been provided the following table of calibration standards from an ICP-MS experiment. (Some text is in German, I am operating in a location where DIN standardization is ubiquitous) I ...
0
votes
1answer
25 views

Which is more efficient way to generate energy using hydrogen: direct hydrogen combustion or through fuel cell? [closed]

Which is more efficient way to generate energy using hydrogen: direct hydrogen combustion or through fuel cell? Please explain so that even a primary school student can understand.
-1
votes
0answers
22 views

Average hydrogen bond per molecule

Is there a uniform hydrogen bonding between molecules in the compound that experiences hydrogen bonding? Let's say for water molecules, the average hydrogen bond per molecule is 2.So does this mean ...
5
votes
3answers
157 views

Is it possible to increase the internal energy of an ideal gas in an isothermal process?

Ideal gas is the one in which there are no attractive or repulsive forces acting and hence its internal energy is due to kinetic energy of its molecules. We may then say, for an ideal gas internal ...
3
votes
0answers
42 views

How to model a molecule of benzene surrounded by 100 molecules of water with molecular dynamics?

I have experience calculating molecular properties (mostly DFT). However, I would like to spend some time on molecular dynamics methods. I would like to ask your advice to direct me towards a program ...
-1
votes
0answers
30 views

Photobromination of cyclohexene

During bromination of cyclohexene in the presence of hv via free radical mechanism, there are two allylic carbons. Why does the major product have only one Br an not a Br on either side of double bond....
21
votes
2answers
2k views

Is “Sulfuric acid… makes a poor electrolyte… very little of it will dissociate into ions” really true? What does that actually mean?

While researching chromate conversion coating for edits to this answer in Space Exploration SE, I came upon the following passage in Corrosion Resistance of Stainless Steel to Sulfuric Acid Sulfuric ...
-2
votes
1answer
52 views

Why isn't canned food good forever? [closed]

So everything inside the can has been killed and nothing can get in. So why doesn't it last forever then?
-1
votes
1answer
59 views

what does it mean to say oxygen in a given context?

My textbook "chemistry by Julia" says the following When it comes to expressing the molar mass of elements such as oxygen and hydrogen, we have to be careful to specify what form of the ...
2
votes
1answer
45 views

What is 'absorbance power' in electrochemistry?

I have been asked $\ce{250 mL}$ solution of unknown molarity of $\ce{CuSO4}$ in water was electrolysed using platinum electrodes. After the passage of a current $2 \times 10^{-3}$ ampere for $19.3$ ...
0
votes
0answers
21 views

Why do we need salt bridge in a cell during potentiometric measurement as there is no or minimum redox activity at electrodes?

In electrochemical cell, we need salt bridge to maintain electrical neutrility in both halves cells during redox reaction?. But in during potentiometric measurement, no or minimum current is drawn and ...
0
votes
2answers
76 views

How many bonds does oxygen really make in minerals?

I'm studying some metallurgy things and interested in iron oxides. The simple 2-D representation of a mineral like hematite shows $\ce{O=Fe-O-Fe=O}$. But the crystal structure seems to show each ...
-3
votes
0answers
37 views

I’m looking for a reusable adhesive that sticks to skin and is safe to use. It needs to be a thin strip that is sticky on both sides

The key here is that it is reusable. I keep thinking of the silicone chest pad that I use, wish can be washed and reused again. It has lasted me over a year and a half, and continues to stick. But ...
2
votes
0answers
29 views

What is the rate constant k for the reaction between potassium manganate and oxalic acid?

For my school's chemistry classes, I am investigating the kinetics of the redox reaction between $\ce{K2MnO4}$ and $\ce{C2H2O4}$. I analyzed the data using a colorimeter set to $\pu{565nm}$. ...
-4
votes
1answer
39 views

What are the products when KCl and H2SO4 reacts? [closed]

I have been trying to find the right answer by googling and I just ended up finding multiple answers. Ans #1: $\ce{2KCl + H2SO4 -> K2SO4 + 2HCl}$ Ans #2: $\ce{KCl + H2SO4 -> KHSO4 + HCl}$ Can ...
0
votes
3answers
59 views

Isomers of a Cycloalkane [closed]

What I know: All alkanes are saturated hydrocarbons with the general formula, $C_nH_{2n+2}$ All alkenes are unsaturated hydrocarbons with the general formula, $C_nH_{2n}$ What's Confusing Me: This ...
-1
votes
0answers
21 views

Raise pH of H2O2 to 10 with NaOH without destroying most of H2O2. Is this possible?

I want to raise $\mathrm{pH}$ of $\pu{20 mL}$ $\mathrm{35}$% $\ce{H2O2}$ to $\mathrm{10}$ with some $\ce{NaOH}$ flake. How much $\ce{NaOH}$ must be added? Does this $\ce{NaOH}$ destroy all of my $\ce{...
0
votes
1answer
43 views

Finding the molecule with the smallest bond angle in the following lists of elements

For each of the following lists of elements, find (and give a justification for your choice) the molecule with the smallest bond angle: a) $\ce{OSF_2, OSCl_2, OSBr_2}$ b) $\ce{SbCl_3, SbBr_3, SbI_3}$ ...
-1
votes
0answers
28 views

Metalic taste of water boiled in electric kettle [closed]

Why does the water, boiled in electric kettle, taste metalic ? Do metalic ions go from metalic plate to the water through electricity ?
-3
votes
0answers
28 views

Does adding 20 millilitre of 40% H2O2 to 100 millilitre cyanide solution decrease pH under 9?

If I add $\pu{20 mL}$ of $40$% $\ce{H2O2}$ to $\pu{100 mL}$ cyanide solution with $\mathrm{pH=11}$, Is it possible $\mathrm{pH}$ decrease under 9 and produce $\ce{HCN}$ gas? I ask this because $\...
3
votes
0answers
52 views

Magnetic behaviour of potassium permanganate

I was going through the properties of potassium permanganate and found this- It has two physical properties of considerable interest: its intense color and its diamagnetism along with ...
1
vote
0answers
25 views

Determining the leaving group for substituted benzene in Aromatic nucleophilic substitution

I could figure out that After the substitution of one of the halogens, with the $\ce{-OCH3}$ group(Electron donating group), the ring would be deactivated towards nucleophilic substitution hence the ...
2
votes
0answers
37 views

what does Area(A) in Randles-sevcik equation refer to? geometrical area of electrode or electrochemical active surface area/

In the Randles-Sevcik equation, $$i_p = 0.4463 \ nFAC \left(\frac{nFvD}{RT}\right)^{\frac{1}{2}}$$ we have an area $A$ in the formula. is this the electrochemically active area or geometrical area? ...
2
votes
0answers
31 views

How many equivalents of Grignard reagent does a nitrile group consume?

I was looking at reactions of grignard reagent with certain kinds of compounds and came across it's reaction with nitrile group: What I was wondering is what if we don't react the Imine formed after (...
2
votes
0answers
28 views

Why is Cu2o[Copper(I) oxide] a (p-type)semiconductor?

Statement: Cu2O[Copper(I) oxide or cuprous oxide] is an extrinsic (p-type) semiconductor. Main Question: But why is Cu2O an extrinsic (p-type) semiconductor? My confusion: I understand how Silicone ...
1
vote
1answer
42 views

Can dehalogenation reaction occur through E2 mechanism? [closed]

I have seen examples of dehydrohalogenation reaction that occur through E2 mechanism but never came across dehalogenation reaction that occur through E2 mechanism (for example, dehalogenation of 1,2-...
2
votes
0answers
9 views

What unit and dimension for membrane permeability / permeation expression?

Context When studying the diffusion of gases through thin membrane, one may use the diffusion coefficient $D$ used in Fick's laws as (one dimension form): \begin{equation} J = - D \cdot\frac{d\varphi}{...
2
votes
1answer
191 views

What does the state of a substance at a specific T and P mean?

From the phase diagram of water, we see that water is a liquid at 20°C, 1 atm. The state of the water at 20°C, 1 atm is liquid. But there is actually also a water vapor in equilibrium with liquid ...
5
votes
0answers
41 views

Why is surface tension of water decreasing as sodium chloride concentration increases? [duplicate]

For my IB chemistry IA, I am measuring the impact of salinity concentration on the surface tension of water (i am using distilled water). My hypothesis is: As the concentration of salt increases, ...
1
vote
0answers
58 views

Linear equations for constructing molecules with covalent bonds

(By training I am a math-guy and my knowledge of chemistry is restricted to school level) I have read a little bit about the electron spheres and sub-spheres, the Aufbau principle and covalent bonds ...
8
votes
1answer
113 views

Out of tropolone and tropone, which is more soluble in water?

According to me tropolone has intramolecular H-bonding, so extent of H-bonding with water will decrease and thus, will be less soluble. Tropone (Cyclohepta-2,4,6-trien-1-one): Tropolone (2-...
-2
votes
0answers
31 views

Phosphate buffer not electroneutral? [closed]

According to the equations below, the phosphate buffer is not electroneutral, except at pH = 7. But it should be electroneutral, right? What did I miss here? In order to prepare $X\,\pu{ M}$ buffer ...
-2
votes
0answers
18 views

Question about TLC [closed]

I conducted TLC to confirm Rf value of toluene. Eluent was hexane+ethyl acetate(10:1 vol). Then I used UV lamp (254 nm) to identify the spot. But there was no any spot. I had understood that toluene ...
2
votes
0answers
13 views

What is an effective preservative for guar gum slime?

I am attempting to find an effective preservative for guar gum slime. I am using typical recipes: A borax solution of 4%, a guar gum solution of 5% using distilled water, and a mix ratio of 20:1 (guar ...
0
votes
0answers
12 views

Common ion effect on Solubility [closed]

The common-ion effect refers to the decrease in solubility of an ionic precipitate by the addition to the solution of a soluble compound with an ion in common with the precipitate.[1] This behaviour ...
1
vote
1answer
401 views

Why is the only natural source of radium compounds uranium minerals?

A common mineral of barium is barytes, or barium sulfate ($\ce{BaSO4}$). Because elements in the same periodic group have similar chemical properties, we might expect to and some radium sulfate ($\...
3
votes
0answers
24 views

What is the power density of graphite user the Wigner effect?

The energy that graphite released upon a cascade of defects by neutron radiation is 2.7 MJ/Kg, however there is no data on how quick this energy is released. I am interested in this as this not ...
0
votes
0answers
15 views

What is the purpose of heterogeneous catalyst pretreatment? [closed]

Below are some questions I have about catalyst pretreatment: What is the purpose of heterogeneous catalyst pretreatment? How is this different than calcination? I have read in the literature about ...
-4
votes
0answers
22 views

Determining pH with given mol/L [duplicate]

Here is the question: Strychnine, C21 H22 N2 O2 (aq), is a weak base but a powerful poison. Calculate the pH of a 0.001 mol/L solution of strychnine. The Kb of strychnine is 1.0 x 10^-6. I am not sure ...
-2
votes
0answers
29 views

If most probable radius is inversely proportional to orbital quantum number, how is energy proportional to n+l

The closer an electron to the nucleus, the lesser the energy. Then why does a 3d electron have higher energy and be closer to nucleus than a 3s electron?
-4
votes
0answers
11 views

Van Der Waals Interactions [closed]

The radius of one sphere is 5 nm, and another sphere is 10 nm. Determine the van der Waals interaction for the following conditions: a) Distance between the spheres is 20 nm and the hamaker constant ...
-4
votes
0answers
35 views

What is Nature of elements and the Periodic Table [closed]

So it’s very basic ,, general chemistry and I’m doing some home study. The first chapter of syllabus is this ? What do I need to know ?
2
votes
0answers
41 views

Construction of the molecular orbital diagram for a species M4

I need to construct the molecular orbital diagram for the hypothetical species ${Li_4}$, which has the following geometrical arrangement: The first step is to identify the point symmetry group. In ...
3
votes
0answers
42 views

How measured content of Calcium Carbonate in eggshells change with the use of different acids?

I am investigating the calcium content of chicken eggshells. The only literature I can find on this consistently and solely depend on the use of HCl to conduct back titration. I conducted the ...
-2
votes
0answers
27 views

According to quantum mechanical model does radial probability distribution show a maxima for lesser values of n ( shell number )

Here is a link where probability distribution graphs varying with radius for different azimuthal quantum numbers are compared to show that most probable radius is inversely proportional to l (...
1
vote
0answers
61 views

What would be the order of reactivity of these compounds in Sn1,Sn2,E1 and E2 reactions? [duplicate]

My problem is that these compounds seem as if their Sn1 and E1 reactivity are identical as the carbocation would of similar nature and stability. For the Sn2 part the first compound seems to have a ...
3
votes
0answers
53 views

How can the activity of ions be more than 1 if the activity of water is 1?

Now, I am quoting Chemlibretexts when they give the activity coefficient of $\ce{LiCl}$ to be $\pu{1.026}$ at the molality of $\pu{2.5 mol kg-1}$ For simplicity, assuming this is aqueous, I'll just ...
-1
votes
0answers
11 views

VD of a container containing A [closed]

V.D. of a container containing A was found to be 20. Now the container is heated due to which A changes according to the reaction nA=An. After the end of the reaction the vapour density was found to ...
2
votes
0answers
35 views

Reason for GC peak splited

I ran GCMS and one of the peak of GC appears: The peak shows some tailing, but there seems to be another peak at right-hand end of the signal. I have already checked the MS and confirmed that there ...
3
votes
2answers
43 views

Anti-foaming agent for HCl + copper chloride solution

I am trying to etch my own circuit boards at home, and have whipped up some DIY cupric chloride etchant (just CuCl with a bunch of free HCl) The problem I have found is that when I try to bubble air ...

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