# All Questions

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### Electrochemical characterization of benzenesulfonamide

I'm trying to elucidate current peaks for benzenesulfonamide, using an acetic acid-sodium acetate 0.1M buffer at pH 5.5 as electrolyte. When doing cyclic voltammetry, I get a voltammogram similar to ...
19k views

### Why are fluorides more reactive in nucleophilic aromatic substitutions than bromides?

In nucleophilic aromatic substitution reactions, why do fluorides react faster than bromides? Ordinarily bromide is a better leaving group than fluoride, e.g. in $\mathrm{S_N2}$ reactions, so why isn'...
202 views

### bond energy calories

I am attempting to optimize interactions for a series of random and test molecules to a protein using docking software. The software uses QM/MMGBSA to calculate free energy in joules (yes it is not a ...
787 views

### How does water deionization process work?

What are the technical/scientific details behind the process of water deionization? How does deionization machines like those manufactured by Millipore work?
41k views

### How does alum improve the settling of particles to produce 'clean' water?

How does the addition of alum — potassium aluminium sulfate or $\ce{KAl(SO4)2}$ — help settle the dust particles in water? There was such a statement in my Year 9 textbook, and so I was wondering how ...
86 views

### Reaction with carbon

Usually maximum time we see then after cooking by gas there is no black spot on the pot. But continually burning can affect the pot surface and makes black powder. My question is: What is the ...
153 views

### “Drinking water” plastic - can I store beer in this?

This is an outdoors & chemistry question. I have an old and functional water bladder, shown below. On it, there are markings that coffee, beer, wine, hot drinks etc. must NOT be stored inside, ...
261 views

### Material that is flexible when cold but becomes brittle when hot

I'm looking for a material that I can use to make a mesh netting. It should be flexible and have reasonable tensile strength when cold but brittle when hot (>$\pu{400^\circ F}$). I want to use it to ...
44k views

### Does an onion completely remove “fresh” paint VOCs and other chemicals emitted?

I have read that paint contains VOCs(Volatile Organic Compounds), and solvents generally, and I could wait for them to dissipate, but i've read there are ways to remove the smell of paint such as half ...
123 views

### Less maintenance-dependent continuous pH testing

I am creating an automated chemical component mixing system (DIY project). One of the features required is continuous monitoring of pH value in my main solution. I do not need it to be very precise, ...
202 views

### To model early earth chemical reactions which types of reactions should be included?

I'm currently working on building a simulator for the early earth to examine the spontaneous occurrence of food generated autocatalytic sets. No one in my group is a chemist, so the bottle neck for ...
2k views

### What is the heat energy required to perform electrolysis equivalent?

The question may be off-topic here. If my concept is flawed, please poke me in the rib (+: Sources on the internet indicate a minimum 1.2Volts is adequate for electrolysis of water; nominally 6V. ...
3k views

### How does toluene react at higher temperatures and why?

Reaction of toluene at high temperatures gives us (o-m)toluene; whereas at normal conditions of electrophilic attack, it gives us (o-p) directing. Why does this happen at high temp although as methyl ...
960 views

### Bond of interest

What does it mean for our bond of interest if we have low bond length and high frequency? Trying to make this connection but am not understanding. If anyone could explain it intuitively, that would be ...
16k views

848 views

### Is it safe to condense water into a liquid nitrogen trap?

I'm trying to remove water from an imidazolium salt (i.e. dry the salt). However I want to know if it is safe to remove the water under vacuum. Is it safe to condense water into a liquid nitrogen ...
3k views

### Sigma and pi symbols in molecular orbital theory

In molecular orbitals diagram, sigma ($\sigma$) and pi ($\pi$) symbols are used. What do these symbols really mean?
257 views

### When measuring avidity should you use the ligand concentration or the nanoparticle concentration?

Looking at avidity between a ligand-receptor, you're looking at an enhancement of the $K_d$ compared to a lone ligand. Is it more appropriate to compare the $K_d$ using the concentration of the "...
582 views

### speeding up etching process of a copper board

Background: I use Sodium persulfate to etch a copper board to manufacture home made Printed Circuit Board (PCB). On the etching powder's plastic, it is written that: 1.5-2dl of etch powder in 1 ...
623 views

### Does variations in air pressure affect the melting point of PLA and ABS while 3D Printing?

Tight temperature controls are needed to ensure that the filament used in fabrication does not begin to "ooze". In places where the air pressure rises and drops during the course of the day there may ...
Humans typically achieve combustion by starting a chemical reaction of a fuel (often a carbon $\ce{C}$ containing fluid like methane $\ce{CH4}$), which is is brought into an an oxidizer (a gas ...