Chemistry Definition and 993 Threads

Hello everyone, I've never used PF before, so I'm not exactly sure I'm posting in the right place. Anyway, here's what's going on : I'm currently preparing a Master's in neurobiology. I stopped studying sciences (i.e., physics, chemistry, maths) in high school, but somehow managed to catch up...

What is the pH of a solution made from 34.6 ml if 3.45*10^-4 M of H2SO4 added to 41.7 ml of 4.56*10^-4 M of Al(OH)3? I know how to find H+ and OH- and pH I also know how to use x mol / L, but I cannot get them to click together. Everyone keeps telling me to use RICE but my professor never...

Hi, I am trying to model a counter flow diffusion flame using ansys fluent with fuel/oxidiser as methane/air. The problem is that the flame temperature(800 K) is much lower than what it should be(>1600 K). I am using Non premixed combustion module with steady diffusion flamelet and adiabatic...

Homework Statement Hydrolysis of ethyl lactate Determine the value of the rate constant for the hydrolysis of ethyl lactate from the following data. Mass of ethyl lactate (grams): 0.5956 Concentration of stock HCl solution (M): 0.01023 Standardization titration volumes (of NaOH): Run...

I was hoping for a bit of advice about the options I'm considering, or if anyone knows of a good place I can ask the same question, that would also be appreciated. I'm considering a few different masters degrees but there isn't really one that I think I'd enjoy significantly more than the...

I have this curiosity about how easy or difficult it has to be to find out everything that is in a person's blood. Through all the tools we have available today, would it be possible to find out what is in our blood? From TSH to blood sugar, to cholesterol, isn't there a simpler way of finding...

Homework Statement Determine [Zn2+], [CN–], and [HCN] in a saturated solution of Zn(CN)2 with a fixed pH of 1.060. The Ksp for Zn(CN)2 is 3.0 × 10–16. The Ka for HCN is 6.2 × 10–10. Homework Equations The Attempt at a Solution I don't have a phone or camera right now to take a picture of my...

I got a D in Gen Chem 1 and a D+ in Gen Chem 2. Mostly because of missing homeworks and I was taking 5 classes at the same time. But when I restudied both of them, and took Organic Chemistry, I managed to get A- in both Orgo 1 and 2. How will graduate school see this? And also, if I were to...

Homework Statement Hi all, I'm fairly new to physics forums so cut me some slack for being a noob. I've just noticed that my brand new snowboard's edge has rusted (oxidised). I live in Australia and it's been stored in my room receiving sunlight everyday. I'm guessing this probably caused the...

Homework Statement Propose a given synthesis of each of the following compounds starting with 1-butene a) 2-chlorobutane b) 2-methoxybutane c) 2-butanamine d) 2-butene (mixture of cis and trans) e) butane The attempt at a solution I have the structures for 1-butene, as well as each of the...

Homework Statement How many atoms of oxygen are present in 300 grams of calcium carbonate? molar mass of CaCO3 = 100g Homework Equations The Attempt at a Solution I don't know how to proceed. Can anyone please help me out by giving the forulae or steps on how to do this problem.

So I have successfully transferred to a 4 year university from a community college. I am majoring in mathematics. I have completed: Calculus 1,2,3, Introduction to Ordinary Differential Equations, Introduction to Linear Algebra, Introduction to Discrete Mathematics. I have also completed...

I was wondering if anyone knows of good self study books to help me in school. I am going to be a sophomore next year and trying to be extremely prepared. Here are the classes: Chemistry Honors World History AP Algebra 2 Honors European History AP English 2 Honors Spanish 3 Honors Thanks...

I have already taken both General Chemistry 1 and 2 at my community colleges. I did not get a good grade, but that was because of I missed a lot of homeworks and projects, but did good on the tests and I understand some of the material that I learned. In general, can you take both of them again...

Homework Statement I have performed a chemistry experiment where I analyzed how the diluting of two reactants with the same volume and initial concentration impacts the percent yield of a precipitate product. Thus my IV was concentration and my DV was percent yield. My question is what is the...

So this upcoming fall I'm beginning college and decided to pursue a BS in Physics. Although I'm not exactly sure what field I want to pursue in physics, I think I want go into quantum mechanics after I graduate and obtain my PhD. Although I love chemistry, it's not what I want to do as a career...

This is the question and the answer, the problem is i don't know how to get to the answer top is question and bottom is answer I attempted to divide the gas concentration by 24 to get molar mass, but that didn't work and how am i suppose to know that OH- is one of the products? i guessed...

Hopefully this is the pot of gold I have been searching for on getting help. I am a Sophomore. Over the course of this entire school year I have really struggled through my Honors Chemistry course. I really don't know what it is, I will say the lectures bore me to death, but I power through them...

Hello everyone, I'm a graduate student in a biophysics lab. I'm trying to run a QM/MM simulation with a protein that binds 3 Ca2+ ions, and as such I am having a devil of a time getting the SCF to converge. I've tried DIIS, KDIIS, damping, and a few other methods to try to get convergence with...

Hi, Does an Atom's Type have to do with the number of protons and neutrons it has? Or are they completely unrelated? Just curious. Thanks :)

Homework Statement To a saturated PbCl_2-solution there is a equally big volume of Pb(NO3)_2 added which has the concentration 0.05M. Is there a precipitation of PbCl2 or not? If Ks is 2,54*10^-4 for PbCl2. The problem here is that I don't know how to find the concentration of Cl2 or Pb. My...

I am doing a lab and we get silver epoxy resin on our double layered graphene sample where we didn't want it. We can take off the silver paint using ethanol but worry it may destroy the thin layer. Will ethanol be okay to use? Are there any suggestions on what to use?

Hi, We have been supplied an Iodine (I2) solution 0.005M.for an experiment but we are supposed to standardize the iodine solution (which i guess means that to find the exact concentration of the I2 solution) My idea is that we should do a titaration,but I don't know how to or what to do. So if...

Homework Statement Homework Equations A=epsilon*l*c The Attempt at a Solution So I was wondering on how to set up the equations now, since I don't have much information? Which equations should i use to solve the problem?

I am a high school student attending school at a community college (Early College High School located inside). I am currently a sophomore and I am signing up for classes for Fall/Autumn. For my Senior year, I want to take Calculus-based Physics but of course, that class is known to be difficult...

Homework Statement Hello, new here! I have a question regarding reversible or irreversible expansions in regards to figuring which equation is needed to figure out work, W. For starters, here is the question: One mole of an ideal monatomic gas is expanded from an initial state of 3 atm and 500...

Homework Statement Ok, I recently started studying again after a 1.5 year break to pursue other things. I am trying to plow through this chemistry course, and I remember this forum where I basically got through my entire physics course because of the help of this forum which I greatly...

I have to take chem I and chem II this summer because I switched to geoscience. I'm worried because everyone tells me its too hard to pass, and it kinda scares me, although I know not to rely on other people's fears to conclude how hard a class is. I finished all my finals this semester, got C...

This is a post sharing some easy to follow tutorials for students majoring in organic chemistry. Hope people in related needs can benefit from this resource.1, ChemDraw Magic - an advanced video lasts less than 15 minutes on drawing molecules faster. As an introduction, the presenter drew Viagra...

Homework Statement Two closes containers are connected by a valve, which initially separates the containers from each other. C Container A has 8.00 L of H2 at 3.00 atm and temperature 400 k. Container B has 6.00 L of O2 at 4.00 atm and temperature 400 k The valve is opened, the gases mix, and...

Hi, My Modern Physics lecturer is of the opinion that the energy dissipated during exothermic reactions is due to infinitesimally small change in mass of the reactants. Similarly, he said that an infinitesimally small part of the food we eat gets converted into the energy using which we perform...

Hi, I would like to learn chemistry, and I am self taught. I would like to learn chemistry to the point, where if i see a chemical equation, I then know exactly what I need to do to synthesize it, and was wondering if anyone could provide any resources for me to do that. Thank you very much...

Hello, I will be taking Organic Chemistry 1 in the fall. I've been reading some sections of organic chemistry 8th edition by john e. mcmurry. This book is required and I was wondering if there's any other chemistry books. When I read it, it makes it hard for me to understand what it's saying...

Greg Bernhardt submitted a new PF Insights post Interview with a Chem-Physicist: DrClaude Continue reading the Original PF Insights Post.

Hi! I'm entering college this Fall and I'm not sure whether I want to pursue a Chemistry degree or an Engineering degree. The college I'll be attending has a very strong chemistry program, and a comparably weaker engineering program, but they have both programs nonetheless. I'm interested in...

So I am in the area in between years 10-11. I am currently on exchange and I have a lot of time so I thought I would study for year 11's topics so that the next few years would be easier. The main subjects I wan't to focus on are Biology and Chemistry. I had bought a book without doing any real...

I want to know if there is a good online source to find and read first-time research papers written by undergraduates(bachelor's research papers) to get a feel for how to write a first research paper in Physics or Chemistry. Can you give me some good places online?

Homework Statement Describe, using sketches, how the following ligands can act as both σ-donors and π-acceptors: CN- P(CH3)3 SCN- Homework EquationsThe Attempt at a Solution I suspect it has something to do with these ligands having lone pair electrons AND open π* orbitals. How correct is this...

Hello everyone. I am a 14 year old student and am truly fascinated by chemistry. As I tried various software, they all had a very complicated UI (User Interface) and confused me a lot as a younger student. After searching a lot, I decided to make my own chemistry software. This is the final...

Homework Statement Predict the number of unpaired electrons [Cr(H2O)6]3+ Homework EquationsThe Attempt at a Solution I under stand how to fill out the MO with the eg and t2g and all but I'm confused about determining the number of electrons. The answers state this is an octahedral d3 but I...

Homework Statement Estimate the vapor pressure of mercury at 25 ∘C (use data from Appendix D from the textbook). Homework Equations Using the appendix I can find ΔG, ΔH, and ΔS. The Attempt at a Solution I have no idea where to start. I think that maybe vapor pressure would be found when...

Homework Statement Introduced into a 1.70 −L flask is 0.120 mol of PCl5(g); the flask is held at a temperature of 227∘C until equilibrium is established. PCl5(g)⇌PCl3(g)+Cl2(g) What is the total pressure of the gases in the flask at this point? [Hint: Use data from Appendix D in the textbook...

I was just hoping for a bit of feedback on how realistic of a transition this would be. I'm nearing the end of an honors degree in chemistry and the job prospects look a bit dire. In my area there are lab technician jobs that require the applicant to have a degree, and the pay is less than what...

I have worked with a professor within my Physics department for almost a full school year now on electron scattering simulations. I run some programs on my computer and analyze them with ROOT. This work has been rewarding as I have learned a lot, but I recently got offered a position in a...

Homework Statement Hi everyone, i have a problem. My brain is short-circuited, and it seems like i can't find out the simplest chemistry in the world :D We made this experiment where we should determine the sugar content in potato flour. We added amylases to break down the starch to glucose...

Recently, in a tutorial session, my professor raises this question. Experiments show that humans don't have free will. Decisions are made by us through unconscious activity of our brain. We are just conscious about the decisions our brain make. We are not actually controlling ourselves. I feel...

I am an undergraduate chemistry student. The school won't provide the list of companies, it's a DIY to look for companies where I could practice my chemistry..fine by me though it's difficult in my country. I had my 1st internship in a chemical company. I stayed there for about almost a month...

Homework Statement From the balanced equation: C3H4O2 (liquid) + NaOH → C3H3NaO2 + H2O Calculate how much Acrylic Acid and Sodium Hydroxide would be needed to have a 5 M concentration in the monomer C3H3NaO2. Use as little Acrylic Acid and Sodium Hydroxide as possible. (Hint: use mL)[/B]...

I used to be a chemical engineer for a bad company that treats its employees very poorly. Ever since leaving that place, I've been trying to transition into the tech industry, because it's where all the new, and exciting stuff happens. I'm particularly interested in battery technology, because I...

Homework Statement Calculate activation energy and pre exponential factor, i need help with the pre exponential factor Homework Equations Temperature °C -20 = 253 k -10= 263 0=273 10=283 20=293 Rate const. s-1 1.15 3.85 11.3 28.7 74.0 The Attempt at a Solution i already plotted the graph on...