Chemistry Definition and 993 Threads

Homework Statement The reaction below has a equilibrium constant of Kp = 2.26 x 10^4 at 298 K CO(g) + 2H2(g) <=>CH3OH(g) Calculate Kp for each of the reactions and predict whether reactants or products will be favored at equilibrium A. (1/2)CO(g) + H2(g) <=> (1/2)CH3OH(g) Homework...

Homework Statement I was doing this problem for HW online, that asks to write the ionic equation for a reaction, but I'm completely stuck. After using all my attempts (i.e., I can no longer submit the answer even if it is right, :frown: ) I still couldn't get the right answer. We've only...

I am majoring in chemistry at UCLA with physical chemistry concentration (transferring as a junior next semester), intent on pursuing research in the field in the future. I would like to minor in mathematics (if a double major is not possible), but I'm having a hard time deciding what classes I...

Hello, I am a student with a chemistry project. However, I am not quite sure what I would like to do the project on. I am fairly ignorant when it comes the recent findings and happenings of the chemistry world. Some of my areas of interest would be biochemical, nuclear, and energy related...

This isn't a homework question per se, but more of a coursework question. Specifically, I'm a bit at a loss as to how to go about learning a particular section of the coursework for a physical chemistry (i.e. thermochemistry) class I am taking. The section in question is that pertaining to...

Hi! I wonder if you could give me some general chemistry book recommendations. I have a modest background in Chemistry (I've read introductions equivalent to "Chemistry, the central science", "Chemistry" by Chang, "Concise inorganic chemistry" by Lee and "Organic chemstry" by Clayden - I've...

I'm doing an EEI on enzymes. I'm using catalase and hydrogen peroxide to produce oxygen. The oxygen is then collected into a measuring cylinder. My three variables are the concentration of catalase, concentration of hydrogen peroxide and the temperature of both. Increasing the concentration of...

Homework Statement http://img51.imageshack.us/img51/9563/chem3.png Homework Equations The Attempt at a Solution I know the answer has to be a or c because you need the ammonia to make this reaction happen but I don't know whether you would want to use 3-oxobutanenitrile or...

How to see if there is a nucleophilic or electrophilic attack? Nucleophilic or electrophilic attack? What type of attack performs a) the water molecule in the attack with one of its free electron pairs? b) bromine molecule when in an attack with a double bond? Motivate! I think...

I'm a chemical engineering major and I have to take one of these. Is QM more theory heavy or are they about the same in that regard? I am leaning more towards QM. my only exposure so far has been with the "modern physics" part of general physics

hey...can anybody help me out...Im an IB student and I wanted to know whether chemistry is required for computer science engineering or not?

Homework Statement If you have 5 mL of Fe(NO3)3(aq) at a concentration of 0.200 mol/L How many moles of Fe ion do you have? The Attempt at a Solution Would it simply be (0.200) * (0.005) = answer or would you have to divide that answer by three since one Fe per three NO3...

Hello, I'm currently a high school student in grade 12 and I was wondering what one could do after majoring in chemistry. I am very interested in it, as well as math, physics, and bio. I want to know what kind of jobs chemistry majors can get and how common some of the jobs are (for example...

Hi there. I am currently a freshman Mechanical Engineering major. I'll try to keep things short. I have a vision for my future; I want to design body armor and personal protective equipment for the military/paramilitary. This interest has lead me to pursue Mechanical Engineering as a...

Question 20 from our final I just took (Analytical Chemistry UF). "You may recall that the wavelength of the sodium D1 line in vacuum is 589.7558nm. In air it becomes 589.5924nm. What is the difference in frequency for these two wavelengths." I said 0. All the other people did the...

Homework Statement For my IB extended essay I want to determine the quantity of salt in comercial popcorns, and analyze if this amount of salt consumption is bad for one's health. I've made my investigation, and read that the levels of salt in these popcorns are quite high, and in the long...

Hi! I am trying to translate a paper on inorganic chemistry from Spanish into English but, since I am not an English native speaker and my knowledge of chemistry is limited, I could definitely use some help in order to get everything right. With regard to the title of the paper (NC =...

Homework Statement Hydrazine was used as a fuel for the Messerschmidt 163 rocket fighter in World War II and for the American Gemini and Apollo spacecraft . What is the enthalpy change of atomisation of 1 mol of gaseous hydrazine? A 550 kJ B 1720 kJ C 1970 kJ D 2554 kJ Use of the...

I am currently doing my GCSEs at secondary school and will have to choose 4 subjects for my A levels, currently I am thinking physics, maths, further maths and history. I also want to be an astronomer/astrophysicist and have heard that chemistry can be useful for that. Would i need to take...

I am chem major currently taking organic chemistry. I am ashamed of admitting I hate organic chemistry. This is not even science. It seems to me though, it is a branch of engineering. You have stuff, you make new stuff. You increase your yield and figure out steps to synthesize something. I...

Hello. If somebody has time can you check my answers? Q1: A gas occupies a 2.0L container at 25°C and 2.0atm. If the volume of the container is halved and the temperature remains constant, what is the new pressure? P1V1 = P2V2 P2 = 2.00 atm x (2.00L / 1.00L) = 4.00 atm --- Q2: The...

Homework Statement hydrzine, N2H4 ia a liquid rocket feul. It reacts with oxygen to yeild nitrogen gas and water. N2H4 (l)+ O2 (g)--> N2 (g) + 2H2O (l) the reaction of 6.50g N2H4 evolves 126.2 kJ of heat. Calculate the enthalpy change per mole of hydrazine combusted I am having trouble...

I have taken general chem 1&2 and orgo chem 1&2, but I honestly don't know how the chemistry I know relates or is used in anything. I can write page long synthesis and mechanisms, but I don't really know what I'm making, if it's safe, or if it's impossible. I only have one chemistry class left...

Hello, I am new to these forums. I am in Year 10 and have decided to take Physics and Maths at A level. However, I need to choose 2 more A levels and have considered Further Maths and Chemistry. I would like to take Chemistry because I love science! But I'm worried there will be too much...

My passion is constantly learning new things about Chemistry, and science in general. I wanted to be a chemical engineer and a chemist when I was in grade 9 but now that I'm in grade 11 and researching about the career as a chemist-- I realize there aren't many job offers, and the pay is low...

Ignoring the school, links, and overall blandness of this website; can somebody PLEASE explain to me what is happening in the picture to the left? http://www.slcc-science.org/chem/ :rolleyes:

Homework Statement For the titration of 50 mL of 0.150 M ethylamine (C2H5NH2), with 0.100 M HCl, find the pH : a) when 10 mL more of HCl has been added than is required b) when 75% of the required acid has been added Homework Equations Maybe Henderson Hasselbalch?: pH = pKa + log (base/acid)...

Homework Statement Write an equation in words to show relationship between mass concentration, molar concentration and molar mass and give a short explanation. Homework Equations I understand that the equation is: molar mass = Mass concentration/Molar concentration The Attempt at...

Traceless protein labeling http://www.nature.com/nchembio/journal/v5/n5/abs/nchembio.157.html http://www.nature.com/nchembio/journal/v5/n5/full/nchembio0509-275.html If this procedure really does work as they say, what a really, really slick idea this group has come up with. Not only...

With the huge interest in click chemistry for in vivo applications--the staudinger ligation and the Huisgen cycloaddition, I was wondering, just how viable are these reactions in real world settings? Assuming second order kinetics, the fastest ever reported Staudinger ligation click reaction...

Homework Statement A Chemist wishes to prepare 250mL of buffer that has a Ph of 4.50. Starting with 100mL of 0.12 mol L acetic acid and a supply of 0.10 mol L NaOh. 1) explain how this can be done 3) how much 0.20 molL NaOH must e added to this buffer to raise the pH to 5.1? 3) if the...

Homework Statement A particular sample of vinegar has a pH of 2.90. If acetic acid is the only acid that vinegar contains (Ka = 1.8 x 10-5), calculate the concentration of acetic acid in the vinegar. Homework Equations Ka = [Products]/[Reactants] pH = -log[H+] The Attempt at a...

Homework Statement http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9701%20-%20Chemistry/9701_s11_qp_12.pdf question 10 Homework Equations The Attempt at a Solution The way I am doing it, is to get two equations in terms of x and y and then equate them. For the first...

I've read a lot of discussions about chemistry vs chemical engineering and everyone seems to favor chemical engineering, mainly for its higher salary and better job opportunities. Every discussion, though, seems to be referring to opportunities with a bachelor's and assume that the asker has no...

I've been doing some chemistry, and come up with a confusing problem that I can't seem to solve. It's a problem I made up while trying to understand the Gibbs Free Energy, but I will try to phrase it solely as a calculus question. It is known that \Delta G + \epsilon \Delta S < 0 and that...

Organic chemistry reaction Help . !URGENT! Homework Statement I can't type the O-Compounds so here's the Question http://dl.dropbox.com/u/41389643/Photo%2001-03-12%204%2047%2021%20PM%20%281%29.jpg Homework Equations The Attempt at a Solution This is the first time I came...

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.

How does concentration of solution (So42) affect the voltage in a electro-chemical cell?

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...

Calculate the number of grams of sulfuric acid in 1 gallon of battery acid if the solution has a density of 1.26 and is 38.5 sulfuric acid by mass.

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...