Chemistry Definition and 993 Threads

So I work at an assisted living facility where part of my job description is to administer medications in the morning. There is one resident who takes Miralax (polyethylene glycol) mixed in with water once per day for constipation. This is a doctor's order, so he must get it every day. The...

I'm a freshman math major and I want to pursue a PhD in math after graduation. I've heard that the job prospects for mathematicians are better if you have a background in another field. So I want to pursue a second major- which I probably would have done anyway because science is awesome...

Hello all, I am a chemistry/physics teacher and our school also is an IB school. I teach both IB chemistry and physics. I have enjoyed and found useful using Asimov's Understanding Physics as a text of sorts for the physics class. I supplement it with problems from other books and sources...

This is the book that is required for my materials science II class but I can't find this book, I can't even find the contents so I can find a similar book. Do you know any?

Homework Statement An aqueous effluent contains 12 M Cd2+ and 10 M Mg2+ as solution of nitrates. Current practice is use NaOH to selectively precipitate the metals. (a) Is it feasible to get 0 Cd impurities in Mg ppt by using NaF instead of NaOH (back up your answer with adequate calculations)...

I apologize if this seems ignorant, but I am at a loss and I need some assistance. I recently built a small vacuum PVD system (Ion source, argon, target material, substrate cradle, etc.) and was showing it to a colleague when it was noticed that my system was unbiased. It actually didn't occur...

Homework Statement A weather balloon is filled with Helium gas and released from the ground. It goes up 18km and achieves a diameter of 15m. Determine if the following values are greater than zero, less than zero, or equal to zero: ΔV, ΔP, ΔT, ΔU, ΔH, Ssys, surr, Stot Homework Equations ΔU =...

I'm a senior in high school and very interested in both chemistry and physics. I have a strong background in chemistry but I am starting to lean more towards a career in physics. Any advice for college classes or decision making?

Homework Statement Homework Equations Huckel's Rule: 4n +2 pi electrons The Attempt at a Solution I'm having problems with the last molecule. I said that the first molecule was indeed aromatic because it has 6 pi electrons and obeys the 4n + 2 rule. The second one is not aromatic because...

Can anyone please guide me how to find solution of this problem A 0.2-g sample of 85Kr gas, which decays into stable 85Rb, is accidentally broken and escapes inside a sealed warehouse measuring 40×30×20 m. What is the specific activity of the air inside?

I just got out of my chemistry lab class at school, and needless to say, I don't think I am going to get a good grade. Basically, I felt like a complete idiot today. My professor was getting frustrated with me because he thinks I wasn't listening to him (even though I was). I never in my life...

Homework Statement Some KCl is dissolved in water at 25°C, where it completely dissociates. The vapor pressure of pure water at 25°C is 28.3 mmHg. Estimate the mass in grams of KCl needed per liter of pure water to reduce the vapor pressure of water at 25°C by 5%. Homework EquationsThe Attempt...

Hi there, I am new to electron theory, and have a question regarding fermi energy. The book I am reading plots the Fermi energy distribuiton function vs Energy for T=0 ( upper right graph in pcture) and for T not equal to zero. The book says that, when T does not equal zero, the decrease in the...

In lab we had to synthesize lidocaine, and one of the steps involved reacting a-chloro-2,6-dimethylacetanilide with diethylamine to form lidocaine. My professor told us that diethylamine-HCl crystals would form and these would help us determine the lidocaine yield (since they form at a 1:1 mole...

As in what are the conditions for resonance (i.e. in oganic chemistry) to occur? Sometimes it occurs, sometimes it doesn't; for reasons unknown. A little help please? :/:olduhh:

Homework Statement Calculate the molarity of a solution made by adding 35.5 mL of concentrated ammonia (28.0 % by mass, density 0.880 g/mL) to some water in a volumetric flask, then adding water to the mark to make exactly 250 mL of solution. (It is important to add concentrated acid or base...

Homework Statement At an altitude of 50 km, the average atmospheric temperature is 0C. what is the average number of air molecules per cm^3 of air at this atmosphere? Given formula: P(sub h) = P(sub 0) x e^(-Mgh/RT) = -(Mgh x 10^5)/2.303RT Assuming P = 1 atm at sea level and h in km...

i am looking for something that includes both chemistry and physics thank you

I was wondering if matter stays at a constant amount. You cannot really destroy anything really because crushing it just turns it into smaller pieces of itself, decomposition turns matter int separate elements, vaporizing just turns matter into gas and burning is a combination of all of the...

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...

When you get the equation for the Gibbs free energy, why do you multiply -T? Can't you multiply just T? I thought about this and came up with an answer of my own, which goes like 'Because its Gibbs 'Free' Energy, when you have that free energy ( \Delta G >0) you have the energy to do...

Homework Statement Provide an acceptable name for the alkane shown below. Homework Equations N/A The Attempt at a Solution I never get these right but...my guess would be 2-dimethyl-5-butononane? My reasoning: the longest carbon chain has 9 carbons so the base name would be nonane, there...

Homework Statement Determine the hybridization of the atoms labeled A, B and C in the molecule and the bond angles around them. Homework Equations N/A 3. The Attempt at a Solution A. Normally, I would say it is sp3 for oxygen since there are 4 groups attached to it including the lone...

Homework Statement If there is a reaction, write out the chemical equation for Hg(NO3)2(aq) + CH3COONa(aq) Homework Equations N/A The Attempt at a Solution The answer says that there is no reaction. I have absolutely no idea why not.

Can anybody link some good inorganic chemistry video websites for a high school apart from Khan Academy Lectures. I found PatrickJMT for Maths videos quite useful. For physics there were many, e.g DrPhysicsA, Doc Schuster videos etc. Usually there are some like chemistnate and ben chem videos...

Homework Statement https://s.yimg.com/hd/answers/i/582779fb3e0b4cecab74f7adb74ed84e_A.png?a=answers&mr=0&x=1422153107&s=7d575e72049bd930d0e263cbd57eff58 The Attempt at a Solution I have attempted to solve it. But I don't know what I'm doing wrong.

Hi all. I'm a prospective physics major, hoping to either go into particle physics or condensed matter research or enter tech if research doesn't turn out to be for me. I was wondering which elective I should choose for next semester--astro 101 or Chemistry 1 or CS 1? Will chemistry help me with...

Hi there! I'm currently pursuing a Bachelors of Science in Physics with minors in both Applied Math & Chemistry and am considering a career in engineering. Now, before all of you engineers jump my case about physics isn't engineering or whatever, please be mindful I'm here for help about my...

Homework Statement I am trying to help my daughter determine the structure of this carbon compound. It has seven carbons, 14 hydrogens and one oxygen. The oxygen must be in a ketone group. Also each carbon is different (as indicated by the carbon 13 NMR). Homework Equations The Attempt...

Ah ha! So I was looking through the physics classes I will have to take and noticed a lot of topics dealing with atoms and the like. Would it benefit me to take the first installment of basic Chemistry? I don't want to take the lab portion just the lecture section if it would be a tremendous...

I asked my teacher, and I was told that volume is the independent variable, and that pressure is dependent. The textbook I'm using said the same thing. After looking up some graphs of the law, I found that both pressure and volume were used as independent variables. It seems counter-intuitive...

Homework Statement Hello, I missed a lab before the break because I was really sick and I need help. I was given the data from my partners for the titration lab and I don't understand how to calculate the amount of potassium hydrogen phthalate used in each trial, amount concentration of the...

The atmosphere consists of two toxic, and unfortunately abundant gases in our atmosphere. Carbon dioxide and methane. Carbon dioxide produced by factories are not needed in the atmosphere and cause harm. So is methane. Acegikmoqsuwy and I thought of an equation to solve this problem: CH4 + CO2...

I want a good book on Physical Chemistry at 11-12(university or pre-un) grade level. It should include topics about bonding(VSEPR, VBT, MO) etc. I also need suggestions about some books on organic and inorganic chemistry.

They say one way to torture a person is to give them choices. I feel this is partly true in this case. I have a goal in mind for either one: if I do physics, I'll pursue nuclear physics/engineering but I go the chemistry route: I'll do biochemistry/forensic science. I've done a lot of research...

Homework Statement Knowing that HCl is strong acid we want to prepare HCl solution of pH=4.2.starting from a solution of pH=2.9.Explain briefly the procedure that should be followed to do this operation. Homework Equations pH=-log(H3O+) 3. The Attempt at a Solution [/B] I calculated: At...

Hi I have been passionate about physics for the last 4 years self taught up to about the first year of university level. I have found this website because now, at this key point in my life i need the guidance and knowledge that people from scientific fields only posses. I am interested to meet...

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...

I wanted to do chemical engineering at a particular uni but was ineligible to enter any of the engineering programs (lets call this uni A). I have 2 options since that uni A is the only uni in my location which offers chem eng. 1) Major in chemistry at uni A and take similar units as chem eng...

I know there are many recourses online. But I'd like your individual input/advice What are some good chemical experiments I can do at home? Thanks

10.25g of a compound, including chlorine is then diluted. So there is 10.25g in the original compound, which is then diluted. 30mL of that solution is combined with an excess of AgNO3 to create 35.5g of AgCl. What is the mass percent of chlorine in the original compound/sample. I got 8.78g for...

I'm planning on taking a second semester general chemistry course in the spring, and I'm wondering what I should study before hand. Based on RateMyProfessor, my teacher is going to be super hard. I took the first semester general chemistry course and I got an A in it, but that was last fall...

Reduction half reaction : Cu2++2e- -> Cu(s) I have a doubt in using the reference electrode. For example if I have the calomel electrode (ESCE=0.24V) how do I use it with the copper half cell? Are these reactions correct? Cu2++2e- -> Cu(s) 2Hg+2Cl -> Hg2Cl2+2e- To get Ecell=0.24+ECu|Cu2+

I am in some real need of advice on the possibilities of my future plans. A bit of background, 32 years old, went back to undergrad at 30 and currently enrolled in a Bsc (hons) degree in Natural Sciences in the UK with my major subject as Chemistry. Plans to give my full effort to getting into...

Strongest bond in chemistry ionic ,covalent or metallic?Bond strength decrease in the following order covalent > ionic > metallic so i think strongest bond would be covalent bonding then comes ionic bonding and at last metallic bonding.Correct me if i am wrong.One more question is water/ice...

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...

Homework Statement Problem: I am told that the first mechanism is operative in saponification. The Attempt at a Solution However, this strikes me as wrong because the first mechanism involves the formation of dianion. Using hydroxide ion to abstract a proton and make that particular...

I was wondering, if ethanol is used in a food, as it commonly is with food flavorings (as a solvent), and that food is then dried out such that It is made into a powder or cereal or something, does all the ethanol completely evaporate? I know ethanol is very volatile and has a low boiling...

Homework Statement The dissociation constant Ka for the acid-base reaction HA-->(H+)+(A-) is given by Ka = products / reactants; but instead of listing Ka, people generally list pKa = -logKa (where log indicates the 10-base logarithm). Similarly, instead of using [H+], people generally use pH...

I've read an article about computational chemistry in which the authors were performing a geometry optimization. For this purpose, they firstly optimized the geometry at HF/6-311++G(d,p) level with full relaxation on the potentiel energy surface (what does that mean exactly ? Can we extract this...