All Questions

Filter by
Sorted by
Tagged with
0
votes
0answers
17 views

Why frozen drink taste wierd after melting?

Not sure if this question related to Chemistry but here it is When you put a soft drink in the freezer (Pepsi) till it gets frozen then you keep it outside the fridge till it melts, the taste becomes ...
-3
votes
0answers
19 views

Conversion of a compound to a racemic mixture of enantiomers

I am studying for the GRE Chemistry and came across this question. I was not sure how to proceed with it. The answer is A but I do not know why. It has been a little bit since Organic chemistry, but I ...
-1
votes
0answers
9 views

experiment of UV assay of Dextromethorphan hydrobromide in a cough medicine [closed]

Hi there so I have the experiment in the title above and the first step was to make up two flasks of a 10 times dilution of the stock solution ( dextromethorphan hydrobromide) in 0.1m of sodium ...
1
vote
1answer
15 views

In crystallography, how does the real space R factor relate to the atomic B factor?

In assessing the quality of different parts of an atomic model derived from diffraction data, you can look at the real space R factor or at the atomic B factor. Do these give the same information or ...
1
vote
0answers
39 views

How do I clean a wash bottle that is used to store DI water?

I want to use a DI wash bottle in lab, but it's been stored in a cabinet with the top off. I want to clean it before I fill it with DI water. Should I just rinse it off with DI water and then methanol?...
-2
votes
0answers
19 views

Can glacial acetic acid be stored in sub zero temperatures? [closed]

Can glacial acetic acid be stored in sub zero temperatures without the loss of function?
1
vote
0answers
36 views

Is this true for conductivity of mixture of two solutions?

Suppose $\mathrm{Na}_{2} \mathrm{SO}_{4}$ has a conductivity $2.6\times 10^{-4} \mathrm{Scm}^{-1}$ and on mixing $\mathrm{CaSO}_{4}$ to saturation, the conductivity becomes $7.0 \times 10^{-4} \...
-2
votes
0answers
10 views

Is inert pair effect or ionic character makes compound more stable? [closed]

If we consider the stability of tetrachloride of carbon family, i thought that due to fajan's rule, PbCl4 will be most ionic and hence most stable but the answer says that CCl4 is most stable as +4 ...
0
votes
0answers
22 views

What is the basicity order of peroxide, superoxide and hydroxide anions?

My teacher told me superoxide and peroxide anion are more basic than hydroxide but according to Wikipedia Given that the hydroperoxyl radical has a pKa of around 4.8 and and pKa of H2O is Acidity (...
1
vote
0answers
26 views

Regarding the reaction of xenon with fluorine gas

In my textbook, under the topic about xenon-fluorine compounds, the following three equations are mentioned: $\ce{Xe(g) + F_2(g) -> XeF2(s)}$ (Xenon in excess / 2:1 ratio) $\ce{Xe(g) + 2F_2(g) -&...
0
votes
0answers
33 views

Mechanism of nitration for 3° alkanes

I've read that nitration of alkanes gives nitroalkanes, but in the case of neopentane, it forms acetic acid. What is the mechanism for this? Do all 3° alkanes give acid on nitration?
1
vote
0answers
12 views

Ortho effect and the relative acidity in aromatic acids [duplicate]

What is the order of the acidity of 2-methyl benzoic acid and 2-isopropyl benzoic acid? I know about ortho effect which states that the acidity of ortho- substituted aromatic carboxylic acids is ...
3
votes
0answers
30 views

How to do a capacitively coupled electrode?

I have an AUTOLAB potentiostat: working electrode (WE, Pt wire), counter electrode (CE, Pt wire), reference electrode (RE, Ag/AgCl solid state). I would like to capacitively couple the potentiostat ...
2
votes
0answers
27 views

Comparing geometries and substrates calculated with DFT for different pathways

As DFT calculation is an excellent tool for confirming and understanding experimental results, I got deep into this field as organic chemist. I successfully isolated interesting transition states (TS) ...
2
votes
0answers
33 views

Can different components show different deviations from Raoult's law?

Introduction: Raoult's law is used to calculate the partial pressures of the vapour phases of volatile components of a solution Given that there are two components, A and B, in the liquid-liquid ...
2
votes
0answers
37 views

Does (BeCl2)n have 3c - 4e- bonding or not?

The title really explains what the issue is here. I would think that it has multicenter bonding akin to $(\ce{BeH2})_n$ polymer because they are pretty much iso-structural (although it shouldn't have $...
-1
votes
0answers
19 views

principal quantum number, azimuthual quantum number sommerfeld

I have come across few books mentioning that principal quantum number (n) is proposed Bohr, Azimuthal quantum number (l) is proposed by Sommerfeld. They also mention that quantum numbers are ...
0
votes
0answers
12 views

What is the explicit difference between ICT and PET for sensors?

I've been reading about boronic acid based sensors for saccharides (glucose, fructose, etc). Boronic acids are able to complex with diols to form boronate esters and if there is a luminophore on the ...
-1
votes
0answers
39 views

Do equal concentrations of hydronium and hydroxide ions necessarily mean a pH of 7? [closed]

Equal volumes of solutions I and II with [H+]=10^-4 M and [OH-] =10^-4 M respectively are mixed.What will be the pH of the resulting solution? I have a confusion about it . Should the pH be 7 due to ...
-1
votes
0answers
24 views

Terms involved in Mean Squared displacement calculation [closed]

I have been trying to understand the concept of Mean Squared displacement for its implementation in code. I have gone through several books (Understanding Molecular Simulation (by Daan Frenkel and ...
-1
votes
0answers
26 views

Why indium and thallium doesn't react with alkali solution? [closed]

It is given in my book that ' In Boron family, only Aluminum and Gallium reacts with alkali solution and not Indium and Thallium' What makes indium and thallium unreactive to alkali solution?
-1
votes
0answers
27 views

how is glow in the dark phosphorescent made? [closed]

what makes the glow more brighter than ever?
-1
votes
0answers
25 views

Why did my sourdough starter that began at a pH of 5 go down to a pH of 3 but then rise again to 4

For a science assessment I am looking at the effect yeast has on a sourdough starters pH over time. In my results I have noticed that out of the 8 tests I conducted 4 of them went from a pH of 5 (the ...
0
votes
0answers
36 views

Chemistry Equations [closed]

How do I know what the equation of a reaction is without knowing what the products are? Am i meant to do trial and error and just guess? Eg: When 3.4g Pentane was burnt in excess oxygen, 165kJ of heat ...
-2
votes
0answers
28 views

How to reduce the acidity of vinegar, without diluting it? [closed]

Ive been drinking a small amount of vinegar for possible health benefits. I would like to reduce the acidity, to enhance tolerability in the body. But I dont want to dilute it too much, as the ...
1
vote
0answers
40 views

Formal way to write a dissolution process

Suppose we have to write a chemical equation for the dissolution of a salt (e.g. $\ce{NaCl}$) in water. Which of the following two ways is the proper and why? First way $$\ce{NaCl (s) + H2O (l) <=&...
0
votes
1answer
50 views

Can suspended solid particulate particles adsorb on surface?

Gaseous and liquid particles adsorb on solid surfaces. Can solid particles suspended in a fluid medium also adsorb on these surfaces in the same manner?
-1
votes
1answer
45 views

Fields of Study in Chemistry [closed]

Is there a standard classification scheme for different areas of study and research for chemistry like mathematics has Mathematics Classification Scheme (MSC)?
1
vote
0answers
31 views

Can phosphoric acid be used to substitute sulfuric acid in the synthesis of thymolphthalein?

I am planning to synthesize thymolphthalein, a pH indicator. I am wondering if phosphoric acid can be used to substitute sulfuric acid in the preparation. I know it can catalyze Friedel-Crafts ...
0
votes
0answers
44 views

pH after adding acid to soil [closed]

I am working on a question of Regional Junior Science Olympiad. I have actually no idea how should I begin. Please guide me. For details, here is the main question Plants absorb several ions and ...
3
votes
1answer
95 views

Lother Mayer curve

While studying about atomic trends, I encountered the Lothar Meyer curve: Similar graph found on internet If the covalent radius decreases across a period, why is the graph of atomic volume ...
-1
votes
0answers
12 views

Calculation of Volume using Van Der Waals equation of state [closed]

It is necessary to provide a chemical factory with a tank sufficient volume to store 100 moles of a pressure of 2.50×10⁶ Nm‐² at 298K. Calculate the volume that the tank should possess according to ...
0
votes
1answer
30 views

Order of Shielding Effect for orbitals

From what I know Shielding effect is the ability of inner electrons to repel outer electrons and reduce the Nuclear charge felt by the outer electrons and this is caused by electron-electron repulsion....
-1
votes
0answers
63 views

What is meant by “non-relativistic”? [migrated]

I am reading a document on cosmology and particle physics (this s the first time I look into something like this). It frequently states the word "non-relativistic" but I do not understand ...
-2
votes
0answers
20 views

PH adjustment calculation [closed]

how to adjust a PH from 5 to a pH between 6,0 to 7,0 with only calcium carbonate available. The mass in mg needed to adjust 5L of water is about:
5
votes
0answers
106 views

How is the vibration of multiple atoms treated in vibrational spectroscopy?

Most of the advanced undergraduate textbooks on physical chemistry/ instrumental analysis show the case of a diatomic harmonic oscillator and derive formulae for predicting the frequencies. The ...
-2
votes
0answers
18 views

Is there any concept of polymerization in Ferric (Fe)? [closed]

Recently I have read a ferric compound i.e polymeric ferric sulfate(PFS)sometimes called poly ferric sulfate, there is not much data on it structure such as XRD, XPS, SEM etc, is that mean there is ...
-4
votes
0answers
22 views

Why co2 and h20 not form when caco3 (aq)react with co2 dissolved in it, although metal carbonate reacting with acid give co2? [closed]

Why $\ce{CO2}$ and $\ce{H2O}$ is not formed when $\ce{CO2 (H2CO3)}$ is passed through $\ce{CaCO3}$ and instead $\ce{Ca(HCO3)2}$ will form? When acid react with metal carbonate it will result in metal ...
1
vote
0answers
21 views

Brownian motion of asymmetric particles

The classic Stokes-Einstein relation ($D=k_BT/(6\pi\eta r)$) it is assumed that the particle undergoing Brownian motion is spherical, and experiences ordinary Stokes flow between (or during) ...
-2
votes
1answer
34 views

What can keep moisture out? [closed]

My team and I are working on our senior capstone project and is looking for someone with knowledge in chemistry or engineering to assist us business students. Could you recommend any material that ...
-2
votes
1answer
42 views

Which electron should be considered the last one?

Today I came across a problem which asked some quantum number informations regarding the last electron of Zinc. Now as far as I have studied 4s subshell is filled in preference to 3d subshell bcos of ...
0
votes
0answers
5 views

Where does the new electron come(beta particle) from in beta decay? [migrated]

In beta decay neutrons convert into proton, in that process they'll release an electron(called beta particle) but mass still remains same $$_zX^A ----> _{z+1}Y^{A}+ e^- $$ The question is where ...
-1
votes
0answers
29 views

Finding Volume of Oxygen needed for Reaction [closed]

Question: Observations of one species of animals on the planet K-22 have shown that they produce energy by following another process similar to the respiration of animals on Earth. They release ...
5
votes
2answers
385 views

Is there a simple way to distinguish grades of purity for copper metal?

Is there a simple way to distinguish different grades of fine copper purity (on a trace metal basis) that can be carried out in a small lab? Specifically, I would like to be able to differentiate 4N, ...
-1
votes
0answers
27 views

What is “Corrected Boltzmann” statistics? [closed]

Just saw a question, "Write down the differences between Boltzmann and Corrected Boltzmann statistics". The thing is, I know about the Boltzmann statistics, but what does the "corrected ...
-1
votes
1answer
34 views

Finding Equilibrium Constant

Consider the following equilibrium process at 686˚C: CO2(g) + H2(g) <=> CO(g) + H2O(g) The equilibrium concentrations of the reacting species are [CO] = 0.050 M, [H2] = 0.045 M, [CO2] = 0.086 M, ...
-5
votes
0answers
32 views

What happens when H2 reacts with CO2? [closed]

So I've seen this reaction: $$\ce{CO2(g) + H2(g) ⟶ CO(g) + H2O(g)}$$ If this is true, won't the CO2 and H2 in the air just react with each other and water will fall out of the sky? Or does it only ...
0
votes
1answer
37 views

Stannous chloride is not dissolving into water

I am trying pcb tin plating. I am following a formula that uses 50ml water 2gm sulfamic acid 0.5gm stannous chloride 3gm thiouria 50ml water The problem is, my Tin(II) chloride is not dissolving. It ...
1
vote
0answers
22 views

What are the references in multi-reference methods?

There is this question: What exactly is meant by 'multi-configurational' and 'multireference'? But I still don't understand what the multiple "references" are. I understand ...
1
vote
1answer
75 views

What are some of the lowest melting point glasses available out there?

I'm wondering about lead-free "glass solder" or any glass frit powder or paste that has a very low melting point (under 400 c). What products are available to the layman, where can I find ...

15 30 50 per page
1
2 3 4 5
783