Chemical Definition and 1000 Threads

Hi. I'm currently an undergraduate student studying for a BS in chemistry and doing pre-pharm courses (I wanted backup career). I've taken anatomy and orgo lectures and labs. What I enjoy from orgo class was that they give you a start and an end, you fill in the rest. I like problems that are...

Homework Statement Without adding any Chromium based compounds, how would you manipulate the above equation to produce more CrO42- ions? Be sure to use chemical equations to show the answer. Homework Equations 2CrO42- (aq) + 2H3O+ <--> Cr2O72-(aq) + 3H2O (l) The Attempt at a Solution So my...

electric transmission between 2 neurons is way faster than by chemical neurotransmitters... then why are there so few electric transmission based synapses in our body??

Hi all! I would like to ask your help! I am a rookie in the subject. I have to admit i don't exactly interested in the mathematical way. I really don't have the "basic" advanced math which would needed it. :) Look at me if i would be a high school physics and chemistry teacher whose imaginary...

This is a very basic question. When I see a chemical formula, like for example combustion of methane: $CH_4+2O_2->CO_2+2H_20$ and I compute the standard enthalpy of reaction $H_r$, do I have always to think about this value $H$ and about the chemical reaction as describing a "certain amount"...

Homework Statement A simple and very violent chemical reaction is H + H -> H_2 + 5 eV (1eV = 1.6x10^-19 J, a healthy amount of energy on the atomic scale). However, when hydrogen atoms collide in free space they simply bounce apart! The reason is that it is impossible to satisfy the laws of...

I was thinking about this: Let's consider a dissociation of some chemical that can run in both directions: AB\rightleftharpoons A^{+}+B^{-} Dissociated form is soluble in a solvent and undissociated form is not - it precipitates. Then the reaction proceeds to the left much faster than to the...

Homework Statement A student performs a single replacement reaction by dipping a strip of copper metal, Cu(s), into an aqueous solution of silver nitrate, AgN03(aq), to produce silver, Ag(s). Write the balanced equation. Homework Equations The Attempt at a Solution The answer has...

Can someone explain me why we could put pi, μi and μiο in this equation: and we get this: (this is The chemical potential of a component in a perfect mixture of ideal gases wher pi is partial pressure)

Right now I have a choice between these two disciplines, Chemical or Electronic engineering. Which one would remain suitable for me? My friends advice me to get into Chemical Engineering since they say its in a huge demand right now, however I am more inclined towards Electronic Engineering...

When you take two magnets one being positive, the other negative. What is the chemical makeup of these two magnets that makes them repel each other. And if I have this correct, electricity is caused by magnet coils spinning around which generates electricity. What is it about magnets (especially...

How does the balanced chemical equation tell us the products are in which state? Solid, Liquid, or Gas or aqueous?

First, thank you for taking the time to read this. I need some guidance as I am inventing somewhat of a new edible product. Curious as to if someone can point me in the right direction for the type of chemist I should actually be looking for. At first I was under the impression that it would be...

Homework Statement The rate of the reaction was studied at a certain temperature. O(g) + NO2(g) --> NO(g) + O2(g) In the first set of experiments, NO2 was in large excess, at a concentration of 1.0 * 10^ 13 molecules/cm3 with the following data collected. time (s) [O] (atoms/cm3) 0...

Hi I am currently using a book called "An Introduction to Thermal Physics" by Daniel Schroeder, and there is a part of the book I am struggling with. So, I am looking for some other book that can help me learn the same stuff (to get a different perspective on the same material). For people...

Hi all, I am really confused at how bubbles are removed in a chemical reaction. Generally it is removed by diffusion...But is there any quantitative equation for that like adhesion energy...? I want to go in this direction to quantitatively analyse the conditions that bubbles are attached or...

hello friends my name is thembile from South africa starting next iam going to study chemical engineering via distant learning i was hoping to be given tips and what to expect and be given recommendations about what kinda books must i study in advance to equip myself regarding physics and maths...

What defines density of chemical substances at the same pressure and temperature?

Homework Statement Given dE=TdS-PdV+\mu dN, PV=NT and Cv=\frac{3}{2}N Find E Homework Equations dE=TdS-PdV+\mu dN, PV=NT and Cv=\frac{3}{2}N The Attempt at a Solution That part that is confusing me is the chemical potential, not sure what to do with it. Finding the energy for the ideal...

Hi, I wonder if you guys could help me. During the summer I used a mould spray on upvc windows which contained anionic surfactants with chlorine bleaching agents. I rinsed this off but it left a white film on the glass and so I used a household cleaner called Flash which has < 5 % Non-ionic...

Homework Statement Write the balanced chemical reactions in ionic and neutral forms for: i) Enargite leaching by sodium bisulfide in basic solution to form chalcocite and thioarsenate. ii) Oxygen pressure oxidation of As2S5 in acid solution to form scorodite. Assume all sulfide sulfur forms...

Homework Statement For the reaction: 2SO3(g) →2SO2(g)+O2(g) when 2.00 mol of SO3 is added to a flask at 10.0 L and 350 K at fixed volume, at equilibrium the ratio of SO2:SO3 is 0.663. What is the values of the equilibrium constant? What is ΔG° at this temperature? Homework Equations...

Homework Statement Consider a monatomic ideal gas that lives at a height z above sea level, so each molecule has potential energy mgz in addition to its kinetic energy.(a) Show that the chemical potential is the same as if the gas were at sea level, plus an additional term mgz:μ(z) = -kT ln...

Hello, My post concerns getting jobs after my Masters degree in Chemical Engineering. I am currently in my 4th/senior year for a BS Chemical Engineering degree. I got accepted in a fifth-year program, so I can spend one more year at school and get my Masters degree. I am excited because I love...

I am currently reading cosmology and I read the statement "... chemical potential which is nearly always negligible when processes are in equilibrium." So the current understanding I got of chemical potential is through the law: $$dE = - pdV + TdS + \mu dN.$$ Hence for processes which occur at...

I don‘t understand one step in derivation of ideal gas chemical potential. Generally Gibbs free energy is: (1) (2) We observe that: (3) From equation (3) we make differential equation and integrate it: (4) (5) We get Gibbs free energy dependence on pressure...

Hi all, I'm a recent graduate of chemistry that wanted to be in chemical engineering but couldn't afford the schools around my location that offered it. While I spend a few years working and saving, I want to get ahead of the curve with the subject before I return to school. Would any kind...

see attached. the main 10" header is water, and the 1/2" chemical injection is polymer feed (not sure how much by volume, we go by pump strokes). problem is during winter, the polymer becomes viscous, and the pump has a hard time pumping the stuff all the way to the header. So we're thinking...

While rubbing the plastic rod with the wool causes the building up of charges on both of them. 1. What chemical reaction takes place between them. 2. Does it create anions and cations? 3. Is it the transfer of free electrons (I don't think so, because generally they are bad conductor of...

Homework Statement While rubbing the plastic rod with the wool causes the building up of charges on both of them. What chemical reaction takes place between them. Does it create anions and cations? Does it create free electrons (I don't think so, because generally they are bad...

Hi, I'm far from a chemist / engineer but am looking for something that will react with glass and cool to around 40 deg F. Any ideas?

Homework Statement I'm just rewording the question, because there is one thing in particular I'm after. Given a graph of A, B, & C in Concentration(y) versus time(x), can you determine the balanced chemical equation? Is that possible? I guess if you found the rates and then checked to see...

Homework Statement The second order reaction 2Mn(CO)sub5 → Mnsub2 (CO)sub10 has a rate constant equal to 3.0 *10^9 M^-1s^-1 at 25oC. If the initial concentration for Mn(CO)sub5 is 1.0 * 10^-5 M, how long will it take for 90% of the reactant to disappear? Homework Equations Rate Law =...

Dear mates: I'm looking for a reference of the chemical engineerin problems: heat transfer unit operation, separation unit operation, grind unit operations, reactor operations for metallurgy and material science industry. Please recommendme the best one you know With all the best...

Question: 2.0 g of a mixture of Na2CO3 and NaHCO3 was heated when its weight reduced to 1.876 g. Determine the percentage composition of the mixture. Attempt: Here is my attempt: Problem: My answers do not match those of the text. More critically, the procedure I've adopted is...

Hello friends. I am an incoming high school senior this year, and of course, the college application process is just around the corner. Despite my harsh troubles with Honors Chemistry last year, it was my favorite class. I am naturally a math & science oriented person, so I know this is the...

Hello, first post here. I'm trying to wrap my head around something here and I'm wondering if anyone can help. I've read that all terrestrial planets have basically the same chemical components - Iron, Silicon, Oxygen, etc - in roughly the same percentages. I also read that the composition of...

Hey guys, I'm 16 this year and I've already decided to be an engineer. it's just i don't know what type i want to become. I am leaning towards mechanical engineering more because i heard you get to break things apart and assemble them. and it's the most diverse engineering branch. i...

hello! is there a degree that studies the interaction between radiation, light, ultrasound, electromagnetic waves, etc with matter? in particular to develop sensors that detect chemical substances thanks!

Dear community fellows Can somebody help me in identifying the name of SnMg2O4 ? Other examples are ZnAl2O4 (Zinc Aluminate), ZnIN2S4 (Zn Thioindate). Kindly provide the reference if possible. Thank You Masood

Greetings all, I have some questions regarding to chemical reaction between Silicon,Si (wafer) and chemical dissolution. FYI, I'm doing electrochemical ething to fabricate porous Si. Could anyone help me to solve this chemical reactions? 1) Si (silicon wafer) + HF (hydroflouric acid)+...

Homework Statement A dilute solution of surfactants can be regarded as an ideal three-dimensional gas. As surfactant molecules can reduce their energy by contact with air, a fraction of them migrate to the surface where they can be treated as a two-dimensional ideal gas. Surfactants are...

Homework Statement A crystal lattice consists of a spin 1 particle at each lattice point. Spin 1 particles can have z-components of magnetic moment that take on the values +μZ, 0, and -μZ. In an external magnetic field B, each spin can have an energy U = -μZB, so the possible energies are...

I'm currently doing my Bachelor's in Physics(1st year). My textbooks aren't too clear on quantum mechanical concepts. "Bonds are formed by overlapping orbitals". I have several questions. I've seen the graph of potential energy versus distance. For some pairs of atoms like hydrogen it dips at a...

I'm a third year physics undergraduate and I want to make 3D Graphene - without spending a fortune. This is my background: I found this review article by Jiang and Fan (Design of advanced porous graphene materials: from graphene nanomesh to 3D architectures) to be very helpful. From what...

Homework Statement Write the formula of : lead(2) permanganateHomework Equations The Attempt at a Solution So I know that this formula is the combination of lead magnesium and oxygen. I know that the -ate suffix means that it has the most number of oxygen ions possible. The answer was Pb...

Does anyone know if chemical engineering is any interesting? I am only considering engineering majors now because of job prospects. Chemical Engineering I heard has a lot of physics and physical chemistry in it. I would like to go to grad school in physics and do something experimental and I am...

Hello all, In chemistry class we recently began the subject of nuclear chemistry. I'm sure you all know that nuclear chemistry unleashes a swarm of new particles. My teacher mentioned the Positron, a particle few of my classmates recognized. To help us understand its nature we were told to...

Title says it all. I'm reading a lot about the transition metal dichalcogenides and I often see something like 2H-MoS_2 What does that 2H- mean? My best guess is that it has something to do with a hexagonal lattice or stacking or something. Anybody know?

Hey all, Lately I've been distracted by a big decision. I am a chemistry major at a small liberal arts college. And boy do I love chemistry! Doing research in the lab is really fun, and I enjoy thinking about chemical phenomena. But I feel like I've been cheating on chemistry lately. I've...