Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties of the soil on the moon (cosmochemistry), how medications work (pharmacology), and how to collect DNA evidence at a crime scene (forensics).
Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are two types of chemical bonds: 1. primary chemical bonds e.g covalent bonds, in which atoms share one or more electron(s); ionic bonds, in which an atom donates one or more electrons to another atom to produce ions (cations and anions); metallic bonds and 2. secondary chemical bonds e.g. hydrogen bonds; Van der Waals force bonds, ion-ion interaction, ion-dipole interaction etc.
What I mean to say is that why are some substituent groups such that(during resonance) the pi electrons' delocalisation is directed away from it while some groups are such that delocalisation of pi electrons is towards those groups?
Can you kindly give some examples too?
Hi all, this is my first post on here so if it is in the wrong section, I'm sorry.
I have been a physics undergraduate now for two and a half years and I'm at the point now where I have some electives I can finally choose. I already have a Math minor finished, but I'm thinking about adding on a...
I'm going to be tutoring next semester and I need a good general chemistry book to review. I used an old copy of zumdahl during general chemistry(not assigned text but worked fine) but I want a fresh look at the subject that is a little more rigorous mathematically especially. After a year of...
Homework Statement
I have this problem:
I known that reaction with TsOH would replace -OH groups with TsO (substitution reaction). (Et)3N would therefore act as a base to abstract H to form an alkene. The problem is i know it should be an E1cb reaction but how do I obtain an alkene? I tried to...
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 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...
1. Question
Start with a organometallic (Benzene)M(Co)3see picture below) and React it with R- to get A, Then react A with I2 to get B and react A with H+ to get C. What is A,B and C?
3. Attempt at answering the question.
I am not sure about the hapticity of Benzene. ? But i am prety sure...
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...
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...