What is Chem: Definition and 424 Discussions

Global Bio-Chem Technology Group (Chinese: 大成生化集團控股), also known as simply Global Bio-Chem, is a Chinese biotechnology company based in Hong Kong. The company is owned by Changchun Dacheng Industry Group.

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  1. TechieDork

    Admissions Will bad grades on Chem & Bio hurt my grad school chances?

    I'm a 2nd year physics student (Thailand) and in the freshman year I was goofing around the campus because I thought the freshman courses were easy resulting in a C+ and a B in Biology. (The exams were far more demanding than I thought) . However,I did quite well on the other courses. -I'm...
  2. Jacob Daniel

    Calculate the "surface energy" of succesively smaller cubes

    Homework Statement NaCl has a density of 2.16 g/cm3 and a surface energy of 2x10-5 J/cm2. Calculate the surface energy of 1 g of NaCl. Initially the complete 1 g is in the form of a single cube (of mass 1 g) and progressively broken into smaller cubes with sides of 0.1 cm, 0.01 cm, 10 μm, 1 μm...
  3. M

    Chem Eng student, scored 990 on GRE Physics

    Hi, so I am from the UK, and we do a levels at school. I had four A levels at A grade (pretty average, hard workers can get A*) and an A at AS physics but my overall A level in Physics was B (I fast tracked the 2 year course in one during my gap year after school). I only needed Bio, Chem and...
  4. sparkie

    Looking for Advice on What to Study [CIS, Chem, ME]

    So, I'm well into my career. I have an AAS in Mechatronics and used it to do controls work for a couple years. I've been an avid "computer guy" since I was about 10. Worked a paper route to buy my first computer, then a dishwasher on weekends for about four months to buy components and build my...
  5. V

    Can someone help me out with understanding inorganic chem?

    2Ca(NO3)2 -> 2CaO + 4NO2 + O2 Why is this happening? Are there any steps I can follow to get to the product? Something like with CaCO3 you remove CO2 because Ca polarizes the radical reducing bond strength.. Honestly I'm having a lot of difficulty with inorganic chemistry, id like to think...
  6. L

    [College Chem] kinetic energy problem

    Homework Statement [/B] atom traveling at 1.00% the speed of light has a KE of 2.016x10-16 kJ. Identify the element. Homework Equations [/B] KE = .5mv^2 Hv= binding energy + KE The Attempt at a Solution [/B] Ok. So I plugged into velocity and me to find my mass and got like 4.48E-26 g. So I...
  7. alphaj

    Organic chem: draw this in line angle structure

    Homework Statement Draw this formula in line angle structure. CH3CH2OC(O)CH2CC(CH2)3CH(CN)CHO. Homework Equations None. The Attempt at a Solution I'm confused with the CC(CH2)3 part of the condensed formula. I knew I got it wrong the first time I drew it because I couldn't just tag three...
  8. M

    Programs Considering a double major in chem and engineering physics

    i am currently planning to pursue a MS in chemistry through a BS/MS. I want to add on a BS in physics or engineering physics (electrical engineering based). I already completed the requirement for a physics minor, but I don't feel like it's enough for what I want to do Or my curiosity.The...
  9. N

    How Many Moles of BaCO3 Dissolve in Water Given Kc?

    Homework Statement Excess BaCO3 is placed in a container containing 5L of pure water. Given the following info: BaCO3 (s) ↔ Ba2+ + CO3 2- and Kc = 5.7E-6 how many moles of BaCO3 dissolve? Homework Equations Kc=(Ba2+ )(CO3 2- ) = 5.7E-6 The Attempt at a Solution solved for x to get .002387...
  10. N

    How Do You Solve a Chemical Equilibrium Problem Involving AuCl, NaCl, and H2O?

    Homework Statement Problem 132 Homework Equations Not sure. I know we will use Kc=[Products]/[Reactants] The Attempt at a Solution I tried to devise a balanced equation to use: AuCl (s) + NaCl (s) + H2O (l) → Au+ + 2Cl- + Na+ and then try solving from there
  11. IoFawkes

    Calculate Work (w) for Isothermal Gas Expansion/Compression

    Homework Statement Calculate Work(w) when 6.5L of an ideal gas at an initial pressure of 34.3atm is expanded or compressed isothermally to a final volume of 34.3L reversibly. Answer in J Homework Equations PV=nRT P1V1=P2V2 w=-nRT In(V2/V1) The Attempt at a Solution Using w=-nRT In(V2/V1) I'm...
  12. T

    What additional courses should I take as a chem major?

    I am a sophomore chem major taking my second semester of organic. I plan on going to grad school. I took calc 2 last semester but calc 3 is not offered next semester so that is sadly out of the question. I can't take classical mechanics without calc 3 and I've already taken prob. and stats. No...
  13. swirlyink

    Physics Double Majoring in Chem and Physics

    I'm currently a chemistry major at a community college. I'll be transferring next fall to a UC here in California (Davis or Berkeley). I still love chemistry, but now I'm wondering if my true interest would be best served by studying physics instead. My interest mainly lies in atomic/nuclear...
  14. yitzchak

    Job Skills Two BS degrees in Chem and Phys w/ Minor in Biochem in May

    Hello. I'm feeling a little bit depressed, desperate and excited, because I am graduating in May of next year. I will have a BS in chemistry, a BS in physics and a minor in biochemistry. What I am wondering is, what kind of job can I hope for with these degrees? I've done research work in an...
  15. A

    Calculating exerted pressure ( gas law lab)

    Homework Statement Mass =0.908kg Area= 5.3 x 10^-4 m^2 2. Attempt This was for a lab I am doing on gas laws. Its asking to calculate exerted pressure in kPa. This is what I've done so far : F= 0.908kg * 9.8m/s^2 = 8.8984N Pressure = Force/ Area Pressure= ( 8.8984N) /( 5.3 * 10^-4...
  16. I

    Organic Chem Nomenclature (need an expert)

    Homework Statement Need help naming these 2 molecules: Homework EquationsThe Attempt at a Solution I think they are: ethoxycyclohexane 5-chloro-2-ethenyl-4-iodobenzonitrile
  17. H

    Guidance for Masters in Chem Eng

    hy, i am hunny. i have done graduation in aerospace discipline. can somebody guide me which subjects of chemical would be the best useful for me if i plan to do masters in chemical engineering.
  18. F

    Schools Community college GPA and Chem grad school?

    Hi, I just have a quick question regarding Chemistry grad school admissions. If a student attended community college before transferring to a UC to finish a BS in chemistry, would chemistry grad schools look at both GPA's when considering them for admission? Basically, would a GPA of around...
  19. M

    Courses AP Chem vs Honors Physics: Choosing the Right Course for College Applications

    As a Junior, I have the option to take AP chem and honors physics. I want to take AP chem very badly but I can't take AP physics without doing honors physics first. I Ultimately want to take AP physics but AP chem seems looks great on a college application. What class should I take?
  20. O

    Courses How many semesters of undergrad chem for phd in physics

    Schools I am looking at only require one semester of inorganic for their BS program. Is this enough if one wants to go to grad school down the road?
  21. C

    Quantitative Analysis Lab Grading: How Strict Is It?

    ANYONE?? In practical AS chem exam if our titration reading doesnot match the examiner how many maximum marks can be cut? If all our calculations and everything is correct using the volume we found how many marks will cut if our titration volume doesn't match the examiners??
  22. MegaAmpharos

    Courses Is taking AP Chem and both Physics C's a good idea?

    I got accepted into my states's residential high school and am going there next year for my junior and senior years. For my junior year I am doing: AP English Lang AP US History AP Calc BC AP Chemistry AP Physics C M and EM (combined) AP Comp Sci I am taking these courses to satisfy prereqs...
  23. O

    Courses A Year Since Gen. Chem I, what to review for Gen. Chem 2?

    Hey everyone, I need to take Gen. Chem 2, and planned on doing it over the Summer in a 6-week condensed course with another 9-week programming class. I'm not sure if this is overboard, but I feel like it should be manageable with no jobs or interns this Summer. The reason I want to take it this...
  24. M

    Chem potential for adsorbed molecule from partition function

    Homework Statement Consider a gas in equilibrium with a surface. The surface can adsorb the gas molecules onto any of M independent, distinguishable sites. The molecular partition function for an adsorbed molecule is q(T) ≡ exp[−β A_surface]. a) Assume that the adsorbed molecules are...
  25. marcus

    Chem analysis to start at best site for low-gravity industry

    Dawn spacecraft is equipped for gamma and neutron spectroscopy to analyze the chemical make-up of Ceres surface material down to a depth of 1 meter. To do this it must first descend to a low altitude--the target is 375 km. It has already descended to within 600 km and it seems likely to reach...
  26. M

    Schools Chem Research for Physics Grad School

    I am a undergraduate physics major currently researching in a astrophysics lab. My PI is away this summer, so I will be unable to research with him between spring and fall semesters. However, I found an opportunity to do work with an organic chemistry group that I suspect I will enjoy (I enjoyed...
  27. B

    Chemistry How to calculate number of moles of H2O2 oxidized

    Homework Statement How many moles of hydrogen peroxide will be oxidized by 0.0045 moles of potassium permanganate in acidic solution? I am unable to think of how you get started? Homework Equations [/B] n - m/mmThe Attempt at a Solution I've balanced the equation for an acidic solution...
  28. J

    Still not on a good start for Gen Chem 1 lab....

    Okay, so here is the deal. This is my third week in Gen Chem 1, and my first two labs so far were an 88 and a 74 out of 100 pts each. I do not know why I am getting this low of a grade. I do the work and I am a good student. I am taking Calculus III and Calculus Physics ATM, so I am a pretty...
  29. ish512

    AP Chem, AP Physics C:M junior year

    Hey all, I am a sophomore thinking about my classes for next year. As far my classes go I am taking: AP Statistics Java I HN Spanish III HN Chemistry HN AP World History Precalculus HN Symphonic Orchestra 2 American Lit & Comp HN I want to take AP Physics C in high school but due to weird...
  30. N

    Quick Organic Chem: P & Q Structural Formulas + Q to R Conversion

    Homework Statement ______________Stgae 1 [/B] P:C3H6O -----> _________________Br2 in organic solvent Q:C3H6OBr2 Stage 2 -->R:C3H5Br3 1.What is the structural formula of P and Q respectively? 2.What is the reagents in the conversion of Q to R?? (1) Phosphorous tribromide liquid (2)...
  31. R

    Chemistry Best Intro Gen Chem Textbook w/ *Conceptual* Questions?

    Hello all, I was wondering, what is a really great introductory general chemistry book/source (covers chemical kinetics, thermodynamics, electronic structure, electrochemistry, acid-base equilibria, etc.) that has a lot of conceptual questions and not just quantitative? An example is like...
  32. M

    Voltmeter values drop w/ time when measuring elec chem cell?

    I set up a zinc-copper elctrochemical cell by placing both electrodes in lemon juice to test the ability of lemon juice to conduct a current. I used a voltmeter and attached each lead to one of the metal electrodes. What I observed was that the voltage over time given on the voltmeter began to...
  33. B

    Programs Is it worth taking ENV S classes as Chem E major?

    Hi all, I'm a 5th year Chem E major in which I'm interested in going into the Environmental E industry after college. I figured that Chem E would be pretty closely related, and I'm wondering if it'll be useful to take some basic ENV S classes before I graduate despite it not really be...
  34. P

    Chem undergrad thinking of doing masters in chem engineering

    Hello, I'm new here and this is my first thread - apologies if I seem forward with my questioning, I really just want some opinions on my issue from people other than friends and family. I've recently finished my second year of undergraduate chemistry, and have received numerous recommendations...
  35. T

    High school Chem and reactions?

    In high school chemistry, which I am in right now, we are the very simple means by which to balance a chemical reaction and determine the products of a reactions. My question is; is any reaction possible as long as the valence electrons of the reactants equal eight? Obviously the answer is no...
  36. N

    What chem reactn gives the highest rate of photons emssn/t ?

    I was trying to google it, but coudn't find any specific answer. Oxidation of Magnesium, for example, emits a lot of light. Is there a table of reactions by high much light they create ? What chemical reaction emits the highest number of photons per unit per time ? Thank you.
  37. T

    Relationship between pressure & chem potential in ideal gas

    Homework Statement (Excerpted from a longer, multipart problem but essentially) Show that for an ideal gas, $$ \frac{\partial p}{\partial T}\bigg)_\mu = \frac{S}{V}. $$ Homework Equations • The ideal gas law, of course $$ pV = Nk_{\rm B}T $$ • Pressure, temperature, and chemical potential...
  38. J

    Atmospheric Temperature and Air Molecule Density Calculation

    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...
  39. J

    Advice for Switching from Chem to ChemE

    Hello, I am currently a junior Chem major. I am deciding to change my major to ChemE. However, my college does not offer it and I would like to transfer to another college. I unfortunately did not transfer last semester and I am stuck for the spring. I am about to start the semester really...
  40. D

    Chemistry What books should I get? Physics and Chem

    Hey I am 12 and my age limitations means nobody takes me seriously. So I am asking those who know what they are doing what books to get. I am teaching myself Physics and Chemistry, but at the current age I am at means the schools and programs do not teach me what is necessary to learn Physics...
  41. mishima

    Well-written Journal Articles in Chem?

    Hi, I was interested in collecting around 3 very nice chemistry journal articles to use as example/inspiration for students writing lab reports. I thought I would ask here before wandering my libraries' archives for a few hours.
  42. H

    How have chemical processes influenced the development of display devices?

    I have been asked to right an essay on how chemical engineering and chemical processes have played a role in the evolution of display devices and upto the new 4K TV.I searched for some ideas but could not find any specific materials.Can anyone provide some ideas?
  43. fluidistic

    Statistical mechanics, ideal gas, Helmholtz FE and chem. pot.

    Homework Statement I am trying to solve a problem but I am confused on what's going on with an approximation. I have to find the pressure in function of V, T and N of an ideal gas using the partition function, then obtain the chemical potential in function of T, p and N and I must graph it in...
  44. B

    Chemical Reaction Review Questions

    Homework Statement Im trying to solve these review questions but am second guessing my answers. http://puu.sh/aKk5W/9695c07739.png http://puu.sh/aKk6y/903fceeb2d.png http://puu.sh/aKkgV/74580ed488.png http://puu.sh/aKkKm/3c1e9d1544.png http://puu.sh/aKkN4/acf042c92b.png...
  45. K

    Physicists: Should I Take Phys. Chem or Gen Chem Course?

    In the following semester I have to take a Gen Chem course. I've read the book, but it doesn't connect to anything we have been taught as physicists so I'm really unmotivated to read it. I have the option to take a course on physical chemistry, which seems a pretty course since it uses...
  46. R

    Freshman schedule help: advanced physics & chem? calc3/lin.alg/diff.eq

    I am going to be an incoming freshman for engineering (undecided, big 4). I am building a schedule that I don't know how to build. Scored 5 ap calc bc. *** My schedule list is * **English**: Freshman Composition (Honors maybe, i don't think this matters much) * **Math**: Calc 3/Lin...
  47. J

    Calc 1, Chem 1, Physics 1 in one semester

    So I am attending Northeastern University as a Physics major and this fall will be my first semester. This year in high school I took AP Calculus AB, AP Chem, and physics honors. Unfortunately a month and a half before the AP exams I had a family issue that required me to miss A LOT of class...
  48. C

    A good chemistry/org chem. Lab manual?

    Hi, I'm looking for a good chemistry lab manual/book that discribes how the general lab equipment works (with pictures and illustrations) how to use it, and perhaps some good lab techniques. What books can you all recommend?