Science topics: Chemistry
Chemistry - Science topic
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.
Questions related to Chemistry
Hello everyone! I'm investigating/evaluating some new etch chemistries to etch and polish Indium Antimonide wafers after a mechanical grind operation. Due to ventilation and other concerns, my lab is unwilling to bring Br2 or Acetic, or Lactic acid in as polishing etch components. I'm having trouble finding chemistries that both etch fast enough to be viable (1.0-1.5um/min) and fully remove grind marks/polish wafer. I would prefer one fast etch that leaves a polished surface after 20-40um.
Failing that, I need to at least find a good polishing etch.
Thank you for reading!
I have seen in the book of mechanism and theory in organic chemistry (1977, Lowrey, et al) that (Me)3P is stronger nucleophile than (MeO)3P. Table 4.5, page 188. But what about alpha effect? I think that because of alpha effect, trimethoxyphosphine should be stronger nucleophile.
when I wash the cells that emit fluorescent by PBS for flowcytometry, emittion of rhodamine b is very low
I am developing a tablet of bcs class 2 molecule. I used here Magnesium stearate, microcrystalline cellulose, povidone K-30, sodium starch glycolate. Coating: Hypromellose, iron oxide black, PEG 400), polysorbate 80, titanium dioxide.
Dissolution media -50 mM Sodium Acetate buffer, pH 4.5, containing 0.75% SDS.
The problem is that when i conducted dissolution test the tablet crumble into large particle and rotated under the paddle. It seems a invisible boundary block them to release.
In chemistry review they mentioned- "during review it was seen that as tablet density becomes very low or porosity very high, dissolution performance deteriorate"
Hi! I`ve got question about DESs. How can I proof the formation of DES? If speak about IR, which regions should I look at and which bands can indicate on the presence of hydrogen bonds? And one more question: the addition of water results full distruction of DES or water will only dilute DES? Is there any information about how much water I can add to the DES before it stop being DES and become "water and dissolved substances"?
I am looking for an article that talks about the direct interaction of a nanoparticle and sars cov-2, but most of the articles talk about target proteins attached to gold nanoparticles, but I'm only looking for the interaction of sars cov2 with the nanoparticles. but I can't find that paper if exist.
(am trying to see the interaction in a solution of gold nanoparticles stabilized with povidone to see if they form clousters or how they interact in general)
In Chemkin "Flame Speed Calculator", to analyze the flame propagation characteristics, we provide an initial temperature and pressure value. But the phenomenon of "spark-ignition" is not at all accounted for.
Although the chemistry mechanism input considers the chemical reactions taking place in detail, the dissociation effect by the electric spark is not accounted for. How can this effect be studied?
We know that superplasticizers' properties vary in terms of PH, Density, Mass average molecular weight, Sidechain density of carboxylic acid groups, Impeller rotational velocity, Viscosity cP, and so on.
I wonder which type of superplasticizer can disperse Nano-SiO2 in water in the best way possible to make concrete?
Furthermore, is there any test that shows how well the nanoparticles dispersed in water?
Does anybody know a good app for Android to visualize cif files?
We tried CrysX, but it shows the cell unit, and molecules look just weird.
Hope you are doing well.
I'd kindly like to ask if anyone may have any available internships/apprenticeships with regards to the field of research. I am a volunteer with IAESTE Malta and am currently in my second year completing a Bachelors of Science (Honours) with Chemical Technology where I place as one of the highest students in my class. I am looking for a 1-3 month period that focus' on spectroscopic technics or anything mycology and/or chemistry related.
I am asking here since I would like to have an experience outside of my country that would be both educational and enjoyable.
Anyone that may know of any offer and/or is offering one please leave a comment or email me through my student email: email@example.com.
Thank you for your time and considerations.
Hello everyone, my research is about leaching of gold from end-of-life printed circuit board by using Fe2(SO4)3 solution and the leachability was approximately 30-40%. Hence, i have some questions to ask.
1. Could these reactions be spontaneous in my solution?
Au + Fe3+ --> Au+ + Fe2+
2Au + SO42- + 2Fe3+ --> Au2SO4 + 2Fe2+
2. If not, in your opinion, what reactions might occur in my solution for gold leaching?
I am working with polyamine surface coating on bio-materials. I have seen in literature that microBCA detects the primary amine in proteins. Similarly, mostly peoples are using it for Dopamin's catechole amine estimation. I am wonder that the same way can I use microBCA for detection of polyamines coated on surface. However, I couldn't find the relevant literature.. I have checked my polyamine changes the color with microBCA and detected their OD values after coating but I am not sure this will be proper to show or not......
Your feedbacks will be highly appreciated
Thanks in advance
I am DO levels in stagnant waters from a stream mesocosm experiment. During the non-flow periods, DO saturation measurements are reaching maximums of 300% (26 mg/L, 21 degrees C). The flumes contained high amounts of filamentous algae and high light inputs, which might partially explain these values. Nevertheless, we are afraid that oxygen bubbles might be generating an artefact.
We are wondering which are the maximums levels recorded by other researchers in similar conditions?
Thanks all for your help and time,
It sounds that shorter λ (more energy) makes the wave more powerful to go through a specific thickness of the material, but the weaker wave does it better. How are the interactions of the wave with the molecules?
I have a serious problem with coating the Pd/C catalyst uniformly on the glassy carbon.
I prepared the Pd/C ink by adding 20 mg of Pd/C into 9 mL of DI water. Then I sonicated it for 10 mins. I added 1 mL of IPA into the mixture and sonicated for another 10mins. I pipetted 5 uL of the ink on the center of glassy carbon (Diameter=3mm) and dried it in the air. To avoid any dusk from the air, I used a biker to cover the glass carbon. But I can't get a uniform layer of Pd/C catalyst on glassy carbon. Here is the picture of the Pd/C film. Can anyone help me with this problem?
When I dipped a copper plate into a heated NaCl solution, a precipitate of copper was found in the solution.
What is the real chemistry behind this?
Good afternoon, I am a student of ING chemistry, could you help me with information on the subject of Biorefineries for my thesis.
I've been looking for some of these sporadically here and there, and have not had any luck. Trying to do SN2 chemistry with dichlorophenylphosphine to produce diaminophosphoranes. Specifically, I'm looking for anhydrous aniline.
Now a days, paralleling of batteries is being done among different chemistry of batteries. Suppose, if I connect lead and lithium batteries in parallel. What will be the current distribtuion and voltage profile of the system. I am searching for literature about it but could not find exact information.
Can some one help me?
My research deals with tertiary amine but my background is not chemistry, so I would like to learn more about amine. Any helpful suggestions will be highly appreciated. Thank you in advance.
When it comes to choosing a good journal, it has always been debated which one is more important? Impact factor (IF) or journal quartile (Q)?
I give an example, you have three following journals, which one would you choose?
1- IF: 1.3 & Q1
2- IF: 2.5 & Q2
3- IF: 3.9 & Q3
Please select one of the three journals above and give a reason for that.
how can I find a common related project between chemistry (polymers or biomolecules) and mechanical engineering( for example fluid mechanics )???
I am looking for a simple software program to model chemical bonds. The purpose is to generate a high-quality graphical abstract for a top leading journal in the field of chemistry. I am not interested in professional programs like Photoshop as I don't have enough time to learn. Any suggestion?
Thanks in advanced!
My question is how can we tell if one functional group of an additive is good for trapping charge (electrons) without causing charge accumulation ?
I'm Juan Carlos, a high school student who is working with electropinning, I made an electropinning machine with a 21g needle and a 30kv high voltage source and the distance between my needle is 5cm (these conditions are already complex that I would not like to know if in their research they obtained that the higher the density, the higher the high voltage must be or if there is any relationship because the electrospinning worked twice but I did not know the density (it was more than 20w/v) and now that I try to find the density trying No I can find it. the solution is pva,i already tried with 20,25,30,35,40 (w/v) without any dopand. i should tried with w/v less than 10w/v? (i dont have a bomb).you can check the video o from one of those times that worked. and the drop is de pva with silver nanoparticles.but now i only lokking for pva electrospining without something. the power supply is a half of medium wave rectified
Hello fellow Template searcher,
I was looking for Analytica Chimica Acta Template but I could not find it anywhere. So I decided to make one my own and share it. Enjoy all the styles that I have created.
This template could work for most Elsevier journals.
Some Oxford Nanopore kits have Primers with 5 ' modification that provide ligation to adapters without the need for ligases (ligase-free method), as in 16S barcoding kits. Does anyone know what modification this is or the chemistry involved in the process? I'm very grateful if anyone can help me with this information. Thanks.
Does anyone has an experience with sodium tert-butoxide? How dangerous it actually is?
Do I need to use a glovebox while weighting and handling it?
Do I have to dissolve it in THF at -30C or room temperature will also do?
How do you store it after the can is opened?
We have 100g of sodium tert-butoxide in total, the planned amount for my synthesis is ca. 1.5 g.
I am interested Research in Glass Chemistry. Expert should please drop information here on where i can have the best supervision, studying under an expert in this aspect of Chemistry.
Hello, I am a 3rd year chemistry student and I'm writing my project report on computational chemistry. does anyone know how PBEsol improves upon the PBE functional?
Thanks in advance
I am working on polishing abrasives. I need to do few characterizations ? which can provide the on time surface chemistry of substrate with polishing abrasive during optical polishing. I would also like to know the physics behind it.
In what case would a reaction rate always show direct relation with activation energy or would it always be an inverse relation? Is it a indirect relation, inverse relation or both case can hold? (Please provide supporting resource, thank you).
I have produced oleum by adding sulfur trioxide, SO3, to sulfuric acid. It mostly contains disulfuric acid (also called pyrosulfuric acid) but i think this method is not suitable for laboratory purpose so is there any feasible procedure for the synthesis of oleum for laboratory purpose?
Suggestions will be highly appreciable.
Can anyone recommend some any software/models available that can predict substance reactivities and the reaction yield under a specific set of reaction conditions process and proposing pathways to synthesize target molecules from a complex mixture?
Chemistry is frequently termed the "central science". As such, chemistry is expected to play a major role in fighting the coronavirus. For example, hand sanitizers and drugs are all based on chemistry. What contributions can chemists make to fight COVID-19?
I am working on my research proposal on the topic, "physical proximity and technology-enhanced collaborative learning in Chemistry. And am going to use the topic matter and change, using CK-12 foundation.
So I know some metal-insulators (ex VO2) have thermochromic infrared-reflective properties, but most of these are insulators at low temperatures and conductive at high temperatures. Some perovskites conduct at low temperatures and insulate at high temperatures, but I haven't found any that show significant thermochromic properties and have a transition around 10C. Does anyone know of materials that satisfy these criteria? The temperature range doesn't need to be exact.
I‘ve got a problem that bugs me for two weeks now but I‘m clueless as to how to calculate the pH so I hoped someone here could assist me. Say we have got a salt made of of a weak base (pkb = 9.37) and a weak acid (pka = 3.98) with a molar concentration of 0.06M and then add an excess of the said weak base (additional 0.02M), how would I calculate the overal pH as I cannot apply the Hasselbalch equation.
Thanks very much in advance.
When I tried to mix a sodium metabisulfite solution with sodium hydroxide solution, the mixture solution quickly became turbid. Before mixing both were clear solutions. Please help explain the chemistry for this observation?
i am trying to formulating one formulation but the problem i am facing is after formulating and adjusting it's pH, when i try to check pH after 7 days it is getting down towards the acidic side.
How can i stop this? which buffer or combination of buffers i can use ?
A question is about positron chemistry. Does the pH of an aqueous solution affect the lifetime of positronium (Ps)? The following references reported that the interactions between Ps and MnO4- was almost the same at pH=2, 7 and 12.
- V. I. Goldanskii, et al., "Observation of positronium reactions in aqueous solutions", J. Experim. Theoret. Phys., vol. 12, pp. 1026 (1960). http://www.jetp.ac.ru/cgi-bin/e/index/e/12/5/p1026?a=list
- T. L. Williams, and H. J. Ache,
Are there any other similar examples? I wonder if it is correct to assume that the lifetime of Ps is unaffected by pH. Or conversely, are there any reports that the lifetime of Ps changes with pH?
I am using finite difference method to discretize the parabolic equation (explicit method), but confused about the chemical reaction term. Solving the generic equation for i specie involves a couple of species in the kinetic reaction equation since it is reversible ( Ex: A+B <-->C ). What is the best way to conquer the complexity in this manner? should I go with separation method and solve diffusion and reaction term separately. I am not quit sure if it is applicable. Thanks in advance.
The oxidation of chloroform is dangerous because it results in phosgene formation under exposure to UV light. Along with the minimization of UV exposure, this reaction is usually prevented with 1% ethanol by mass (or less commonly, amylene). I find this information everywhere online, but never find a clear explanation of why this is the case.
Since isopropanol is so similar to ethanol, how come people don't use it to stabilize chloroform? Does it not work? Is it because its less volatile than ethanol? Does the prevention of phosgene primarily work in the gas phase?
Also, what would happen if the concentration of ethanol was increased from 1% by mass? What would be the problem with this aside from purity concerns? Would the same concerns apply to isopropanol if it does stabilize chloroform?
To date, I have had the opportunity to explore several open source and private software like MFiX, Fluent, Sim-flow, Barracuda VR, PHOENICS, etc. I want to investigate 3D, hydrodynamics (include particle behavior), chemicals and radiation heat transfer maybe.
But I saw different problems when I tried to importing geometry as STL on each software.
Which software are you using when you solve this type of analysis?
I was asked to include Stewart acid-base chemistry into a lecture I have and then I became very confused when I tried to read about it. It is there stated that it is the ion gap between positive and negative ions that creates pH changes by interacting with water. A negative value will for example lead to that H+ is donated from water to neutralize the charge difference. What I do not understand here is that it is impossible to take H+ from water without creating OH- at the same time. This would violate the law pH+pOH=14 and it will also not help to neutralize the charge difference. Is there anyone else that understands where OH- go in this case? Is it going to neighboring tissues?
Is it possible to calculate entalphy of LiBr/H2O or another solution if we know correlation of specific heat without using any software?
In a few reference books of environmental engineering is mentioned that maximum acceptable concentration of nitrate is 10 mg/L as N. What's the meaning of "as N" in this unit of measurement? What's the usage of it?
Thanks for your assistance
In the structure of many drugs, there is a carboxylic group
What is the significance of this group? Why should it exist in the structure of a drug?
Do you know any article or book or reference about this subject?
Thanks a lot
The common method for phosphorus solubilization efficiency measurement of soil microbes is zone formation in agar media (generally Pikovskaya media) but this is a qualitative study. However, there is also a liquid culture method with insoluble phosphorus in liquid media. The estimation of available phosphorus by ICP-OES is quite promising and precise.
The cleavage cocktail is composed of Phenol/thioanisole/water/TFA/triisopropylsilane. I only prepare 10 mL cocktail per peptide but can the activity of the cocktail prepared at 100 mL last for a week?
I prepared PVDF in a very regular way by dissolving it with stirring at room temperature
but when i placed it in vacuum for eliminating the bubbles and trapped gases it started to burst and splash
Does it happen that one has experienced this as well
Is there any reason for this behavior ?
I'm a student in an engineer school in chemistry. I have to do some research about encapsulation for pharmaceuticals applications.
However, there are 2 characteristics about capsules that I can't find anywhere...
What are the thickness and porosity required for capsules for pharma. applications ?
Thank you in advance,
Have a good day !
To have the desired grain size in 6061 and 6063 Al alloy, what should be the minimum % of Ti and B pick up and what is the chemistry/metallurgy behind that?
Any significant progress in the design or innovation of solid catalyst for biomass hydrolysis and sugar fermentation into alcohols in a biorefinery? If yes, I would like to have some recent updates regarding that subject. Thank you all
I am doing an allantoin assay in urine and all the protocols seem pretty vague. I am currently using this website which seems to be the most helpful:
It mentions that I use 15 mL tubes, but since I am boiling the samples should I use glass tubes with a cap to prevent escape? Or can I just use plastic tubes like the ones here:
Is any way or method to seal agarose pad or channels fabricated agarose gel pad to glass slides as like we do plasma bonding with PDMS to glass slides?.
For those of us in chemistry, environmental science, civil engineering, industrial chemistry, analytical chemistry, chemical engineering, biotechnology etc this paper might be helpful. Link is below
im looking for a diy at home (home lab) molecular magnet in a chemical suspension that is stable at room temperatures and cheap
Need to form uniform coating of ZnO with readily available ZnO powder on a substrate. So which liquid solvent I need to use and which procedure I need to follow to prepare such solution? Very new to field of chemistry. Please help
It is known that scientific knowledge is replicated each time at more unusual speeds, however, humanity expects more from our scientific work, that is, solutions to problems that have accumulated and that it is necessary to solve to improve the quality of life . It would be good to reflect on those expectations.
Environmental pollutants and hazardous are major issues through which the modern world. Among all the environmental pollutants and hazardous materials how much contribution is from chemists (out of 100%) lets put rough estimate.
Environmental pollutants and hazardous are major issues through which the modern world is suffering. Among all the environmental pollutants and hazardous materials how much contribution is from chemists (out of 100%) lets put rough estimate.
I have been thinking about a material that was made 6 months ago, which is a tetramethylsiloxane linked to a thiazolidinedione and finally to a naphthalene, but I can't find the original paper (if someone can find it please tell me) but that material had a time of duration of 2 hours until the bond of thiazolidinedione to naphthalene is broken and the material is no longer hard but I know it is an isomeration but the bond does not know why it occurred, could someone tell me that defines the time of the bond in molecular switches or is there any related role please?
I have a difficult to dissolve drug, previously I used DMSO to dissolve it but I want to avoid the toxic effect of DMSO, so I am planning to dissolve it in methyl-cellulose and use tween 80 to emulsify it. Can I prepare it and use it within a week or should I prepare it everyday and use it freshly.
Thanks a lot,
Which of the following majors is more suitable for studying at international universities for the master's degree in chemistry? Please apply the following items in your final answer: 1- Average income after graduation in the United States or Europe and 2- Ease of admission to international universities 3- Number of jobs available after graduation 4- working in the field of medicine and pharmacology etc.
- Medicinal chemistry
- Organic chemistry
- Nano Chemistry
- Analytical chemistry
At the moment we are looking for "nice" reactions employing BuLi solutions for our practical training at the university. We aim to expand our five standard BuLi reactions to a broader field.
Therefor if you know suitable reactions for that purpose please write a short answer. Links or literature citations are also welcome!
"Didactically valuable" reactions with simple starting materials would be of special importance.
Thank you very much!
Recently, I came into contact with a new discipline named chemo-mechanical coupling. I found that chemo-mechanical coupling phenomena exist in many research areas, ranging from development of advanced batteries, biomechanical engineering, hydrogen embrittlement, and high temperature oxidation, etc. Although it is very important in engineering field, I can't know the main mechanisms of coupled chemical and mechanical interactions. Can you give me some suggestions? Such as, some related publications or research project. Thanks very much.
How have collegues overcome inertia to the introduction of alternative practical procedures in high school/seconday school chemistry lessons?
These are difficult times for presenting practical work to students in schools. Social distancing and cleaning of equipment to reduce the spread of the virus has meant that the amount of student practical work has been reduced, even stopped in some schools in the UK. By alternative procedures I mean microchemistry techniques, “green” chemistry alternatives and specific practical designed to challenge the misconceptions which abound in our subject. Misconceptions arise because we are dealing with particles, which are so small they are invisible to the naked eye, which may be electrically charged and are in constant random motion, colliding with each other..
Reasons provided by teachers involve constraints set by National Exams, bought-in courses, Textbooks, lack to continual professional development (CPD), cost of equipment and chemicals, lack of inspiration and encouragement from education manager and suitability of the room being used. You may suggest more.
Do you finding writing in peer-reviewed Educational Journals useful?
Do you find non--peer reviewed social media such as Twitter or Facebook, reaches far more teachers and has more impact than Journals, becaue it is short snappy and attention grabbing.
I would like to hear your views.
In my personal experience I have find the higher rate of sprouting when fresh cow dung is applied on the top side of cutting what might be its reason.
I'm writing a chapter about the nitrogen cycle and discuss the different forms of reactive nitrogen such as NO3 and NH4. I also have some soil places where I discuss soil cations and others where I discuss plant nutrients such as "In a study with Sphagnum spp., Ca and Mg foliar content decreased as N deposition increased..." When should I show ionic charge? Thanks.
I have a 200 mg/ml ampiciline solution, how much should i add to 300 ml of LB medium to get the final concentration of 40 ug/ml?? How much bacteria (in ml) should i add to 75 ml of medium to dilute the culture 50 times??
I have 5 Samsung 21700 - 50 E (NCM chemistry) cells. I want to do basic charge and discharge by connecting it in series. Does anyone know if there is a cell holder available online for single cells? Or how to connect these cells and make contact?
Thanks in advance
I need to get BrHPP for expanding Tgd cells, so if anyone knows about a biotec/chemistry company that has it commercially available I would appreciate the information.
Hi every body,
I have tried to synthesis aliphatic isocyanates from their acylazide compounds based on Curtius rearrangement. Based on articles, the converting of acylazide to isocyanate must be done through a simple thermal treatment in toluene or benzene at 1-2 hours and via the evolution of nitrogen gas during reaction. However, I have repeated it many times and no isocyanate is formed after reaction. Could you please share your experience with me?
Unfortunately, I found no repeatible results from articles.
Thanks in advances
I am looking for methods according following topic:
Vegetable oil (raps) contaminated with hydrocarbons (e.g. motor oil) shall be purified and separated from hydrocarbons. (Usage for in-situ soil remediation)
Thank you all in advance, I am looking forward to your ideas and suggestions.