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.
which is the best leaving group?
Cl- enolate NR3
I couldn't figure out how to draw the enolate here, but it is a basic 3 carbon one.
I believe the answer is Cl because resonance on the enolate will disperse the neg. charge. Am I on the right track or is there a factor I am missing?
Homework Statement
Which is more acidic, and why?
H_{2}SO_{4}
H_{2}SeO_{4}
Homework Equations
The Attempt at a Solution
Because Se is larger, it has a weaker Coulomb force with the H atoms. So it will more readily give up the protons of the H atoms. Hence it should be more...
Homework Statement
So I'm doing a lab report on the reaction of food dye with bleach. I have a couple of questions:
1) What's the difference between pseudo rate constant and rate constant?? (i.e. k' vs. k)
2) How do I write the rate law for this reaction? I graphed the data and found the...
Homework Statement
Find the product of this
http://www.webassign.net/ksorgchem2/14-P-019e1.jpg
The Attempt at a Solution
I tried this but it is wrong.
http://www.webassign.net/marvinimages/e/d/b3dfb33e165ce17f7b0a8bab7b9d9d.png
Not really sure what to do now.
dienophile and diene help?? organic chemistry
We never really covered how to do diels alder reactions and I am having trouble how
to do these. Here is a photo of the lab page with the questions. I just need help
with 2a-e and 3b-3d. Thanks.
So I am almost done with my Chemistry Major, but I really enjoy physics!
Is it possible to still go into physics, maybe Chemical Physics, Astrochemistry, or Material Science.
I don't want to start over, but can I still go into graduate school in Physics?
Homework Statement
A cube of gold is heated to a temperature of 94.2 degrees celsius, and then submerged in 31.3 mL of water at an initial temperature of 28.7 degrees celsius. If the final temperature of the water is 45.6 degrees celsius, calculate the volume of the cube of gold (s=0.130...
Our chemistry book is a good textbook. It explains things well and in depth. The problem I have with it, however, is the exercise problems. Enough of the answers in the back of the book are wrong that it causes confusion with the proper way to solve certain problems (professor agrees and has...
Hello,
I am a high school student looking for resources to prepare for the US National Chemistry Olympiad. I have already taken AP Chemistry (although my teacher did not cover a few topics, such as coordination compounds) and I did well in the class and on the exam.
At this point, I need...
Hello. I've been reading this forum for a couple of days and noticed that it is a lot of people with Ph.D degree in different areas so I thought this was the perfect place to ask for such a thing.
I am a 17 year old student and I find chemistry (Especially theoretical) very interesting. I...
Assalamu Alaykum (peace be upon u in arabic),
First of all, sorry about the thread name, because once u read this thread, there is more to asking about a chemistry question. And as a new poster, i have no clue how to fix the names of the threads i post.
I am a sophmore in high school...
I am currently taking AP Chemistry in high school but I need help. The textbook we are using is the 8th edition of Chemistry by Thomson. however I find that it doesn't explain the math portions very good and is more about memorizing. I also have the Princeton review book on chemistry. Our...
Homework Statement
What is the concentration of all ions after 600.0mL of 2.00 mol/L Barium nitrate is added to 100.0 mL of 2.50 mol/L sodium phosphate.
The Attempt at a Solution
I first wrote down the equation : 3Ba(No3)2 + 2Na3PO4 = Ba3(PO4)2 (solid) + 6NaNO3
I then found the moles...
I have to decide on what subjects I want to continue on for A level and was just wondering what I should pick as my last slot.
I want to do Electrical Engineering at uni when I leave school. I'm really interested in either really big applications of EE like large HV plant stuff but also I'm...
Okay so I was just sitting around and thinking about Hydrogen (weird I know) when I realized that a hydrogen ion is just a proton. So how do we distinguish between molecules such as Cl+ (Chlorine with extra hydrogen) and HCl?
Any ideas what the inherent flaw in this experiment is?
Homework Statement
In the lab (actual lab), we combined copper(II) sulfate pentahydrate with barium nitrate to form barium sulfate (precipitate). Every group got a 115% or higher yield than stoichiometry would predict.
Ba(NO3)2 +...
In basic chemistry courses you will learn that diaphragm prevents mixing of solutions between half-cells while maintaining ionic conductivity. What exactly carries charge through diaphragm if it's neither electrons, nor ions from the solution? What is the molecular mechanism behind that?
function: e^-(x^2/2)
operator: d^2/dx^2 -x^2
The answer key says the function is an eigenfunction of the operator with an eigenvalue of -6.
I can't figure out how to reach this conclusion. Also, Wolfram Alpha says d/dx(d/(dx)e^(-x^2/2)) = e^(-x^2/2) (x^2-1). Isn't this inconsistent with...
Homework Statement
A carbanion is a species that contains a negatively charged, trivalent carbon.
(a) What is the electronic relationship between a carbanion and a trivalent
nitrogen compound such as NH3?
(b) How many valence electrons does the negatively charged carbon atom
have?
(c) What...
Homework Statement
Why do transition metals tend to form +1/+2 ions? Take electron configurations into account so that I can better understand this "easy" concept.2. The attempt at a solution
I think it has to do with the s orbitals. These, I think are valence electrons that are easily lost...
I'm currently an Honours Chem student at UBC (I'd say a fairly reputable school), but I'm slightly disenchanted with the program. I absolutely hate organic chemistry, and there's just not enough math thus far. I'm thinking of either elaborating my degree so I do a Combined Honours in Chem and...
One cubic mile of sea water, with a density of 1.13 g/cm3 contains how many gallons and how many tons of sea water?
1 cm3/.001 L
3.785 L/1 gal
1 kg/2.2046 lb
5280 ft3=1 mi3
1.13g/1cm3 X 2.2046 lb/1000 X 1 cm3/.001 L X 3.785/gal
After this point I get a bit confused...
I'd like to study Physics after Gymnasium (equivalent High School).
How impotent is Chemistry in the different fields of physics? I still haven't decided which direction at all to do in physics, and I'm thinking what would be blocked by not doing Chemistry?
I have Chemistry right not, but...
Do Chemistry majors have to take the same calculus as do Engineering and Math majors? At my university (UC Davis), they do. I'm wondering if it is the same at your university or at most universities. I'm wondering because I'm considering majoring in Chemistry (switching out of Engineering), but...
Basic chemistry: sulphur dioxide shape??!
I realize this isn't homework, but it's so basic I'm ashamed of putting it in the chemistry section. I'm trying to self-teach here, but my textbook is awful and I'm even worse.
Question: Workout the shape of SO2.
Step 1: Draw lewis diagram to work out...
I'm a junior in high school and among other advanced courses I am taking AP Chemistry 2 which is by far the hardest. Now I've had difficult classes before but I have a good work ethic and am able to work through them no matter how hard and come out with an A. While I still have an A in chem as...
As title says, how much chemistry would I need at the beginning of university level particle physics? If I decided to study it, would the fact that I don't have chemistry in my A levels could be a problem?
i have done the maths based on an online conversion calculator that said 1 liter of air is equal to 0.001m^3 in volume. my chemistry teacher tells me that my maths is wrong but won't tell me how...
here is what i wrote:
Failing the above, a larger crucible would hold more oxygen and the...
I want to improve my scientific language and broaden my vocabulary, what will for sure help me in writing my physics and chemistry essays. Can You recommend me any book, which kind I mentioned in the topic?
Hello all,
I am rather new to these forums, and I have a question about lateral transfer between chemistry and physics. First, my background pertaining to physics:
MATH:
3 semesters calculus
1 semester each: ordinary differential equations, linear algebra, abstract algebra, probability...
I see a lot of quacky sites about acid/alkaline body chemistry claiming that lemon juice and orange juice make the body alkaline. They both contain citric acid, orange juice also has lots of potassium... I cannot think of any mechanism whereby citric acid would somehow cause a persons body to...
Homework Statement
10.11g of CaO (molar mass = 56.08 g / mol) is dropped into a styrofoam coffee cup containing 157.0 g of H2O at 25.0ºC. If the following reaction occurs, calculate the final temperature of the water assuming that the cup acts as a perfect insulator.
(Assume that the...
Colligative Properties, Freezing Point Depression -- Chemistry Lab
Homework Statement
In an attempt to hurry the experiment along a student did not completely dissolve the unknown nonelectrolyte. Will the freezing point depression of the solution be larger, unaffected, or smaller compared to...
I was reading in my chemistry book about significant numbers. Also about measured and exact numbers. From what I understand, a measured quantity can be different than an exact number. The book said when comparing something, like 1 lb = 16 oz, it is an exact number because the two are the same...
Hello, I need your help on a calculation...
I have 200 milligram dissolvable tablets, and a 3 ounce dropper bottle of water. How many tablets would I need to add to the water to make a 2% solution?
The chemistry/math is a bit confusing to me because the tables are measured in mass (i.e...
Hello PF members ,
I am in class 10th presently in India.
I want to be selected in engineering entrance examinations. In India best are IITs ( Indian Institute of Technology)
Now there are certain coaching classes in India which prepare us for engineering entrance exams and consists of...
Homework Statement
Problems: http://imgur.com/qN7Iq
Homework Equations
n/a
The Attempt at a Solution
For the synthesis, I tried opening the epoxide with HBr and then adding OMe- in HOMe to substitute the Br with the OMe group in the product. However, I am unsure how to substitute the...
Hi everyone,
I am currently a Junior Chemistry Undergraduate at UofA. I already made my decision that I want to apply for chemistry graduate school after I graduate from my undergraduate study. Based on several good discussions with other graduate students at my school, they all told me to take...