CHEMISTRY (WEBWORK)

1,475 results, page 7
  1. chemistry

    Good day to everyone My class has just started a "Chemistry systems in Equilibrium" unit and I have a question I would like answered if possible, I would truly appreciate this. My Question: How will the following system change when F2(g) is added to a
  2. Chemistry

    Hi, I am totally confused with this chemistry because none of this stuff is in my book, so I come to the great ones with my question: 1. Can you show me how to convert celsius to farenheit (please show me an example and your work so I can get it please) 2.
  3. Math

    In an examination of a certain class, at least 70% of the students failed in Physics, at least 72% failed in Chemistry, at least 80% failed in Mathematics and at least 85% failed in English. How many at lest must have failed in all the four subjects ?
  4. English-Article on the Hunger Games

    This is for my magazine on the Hunger Games, I did an article on Sponsers which Katniss and Peeta got the most. Katniss Everdeen is the main character in this book and Peeta is a boy from her same district. Their names were drawn from this glass jar and so
  5. College Chemistry

    Calculate the electrode potential of a copper half-call containing 0.05M Cu(NO3). E^0 Cu2+/Cu = 0.337 V College Chemistry - DrBob222, Tuesday, April 20, 2010 at 5:19pm E = Eo - (0.0592/n)log[(Cu)/(Cu^+2)] Substitute 2 for n and 0.05 M for Cu^+2 and 0.337
  6. DrBob222

    Im in the 10th grade in Chemistry 1 Honors. Im learning to write a chemical equation. Im confuse on that statement i was given for my homework. The products and reactants are just magnesium Sulfide and magnesium and sulfur? Then why are they talking about
  7. chemistry

    Dr Bob, Thanks for your help. Ihad googled for 3 hours before asking you. For future reference, if anyone asks this question again, 10th grade chemistry, I found a video on You Tube that makes it easy to understand. It is, The Sci Guys, Ph indicator,
  8. anthropology

    A school paper I'm writing says I have to describe 2 reasons along with 2 examples why its important to have a code of ethics in anthology vs chemistry or physics. Only think I am coming up with as to reasons is because anthropologists deal with people
  9. URGENT Science question

    Justin wants to be the captain of an aircraft carrier when he gets out of school. Which subjects should Justin study to help him prepare for this career? biomedical science and meteorology oceanography and paleontology chemistry and biology physics and
  10. Science

    Justin wants to be the captain of an aircraft carrier when he gets out of school. Which subjects should Justin study to help him prepare for his career? A.biomedical science and meteorology B.oceanography and paleontology C.chemistry and biology D.physics
  11. chemistry help

    our teacher said on our final chemistry lab test there will be a question asking us to convert nanometers to wave numbers, anyone know what the question might be phrased like? also, im not sure i know how to convert, anyone have an example question with
  12. Chemistry

    Analytical Chemistry question: Find the pH and the concentration of each species of lysine in a solution of 0.0010 M lysine*HCL. I know that the pKAs of lysine are (1.77)(CO2H) 9.07 (-NH3) 10.82 ( -NH3) but I am not sure where to go from there.
  13. Science

    I'm really bad at Biology and Science in general. Chemistry and Physics will be difficult for me because I'm not good at the Science branch even though I study and work hard for Science/Biology. What can I do to improve?
  14. chemistry

    Dear Dr. Bob, Go to this website listed and you will see that this is not a take home exam. This is my professor's website and you can see his comment on the exams we took today 7/7/10. I just want to know what my score is so I can just relax. type in eee
  15. College chemistry

    This is my first time taking chemistry and I am VERY VERY confused On the step involved to find out how many calories to warm 58mL of water from 10 degress C to 100 degress C and vaporize it at 100 degress C.
  16. Chemistry

    I was doing a lab today in chemistry, and I do not know if I got my measurements correctly. My teacher gave us a strip (probably 5inches) of Mg. We measured it, and then after that, we had to burn it, and measure the mass of it after it was burn. Would the
  17. chemistry

    Would a damp filter paper affect the theoritical yield, calculated actual yield and calculated percent yield. Please help. Chemistry is hard.
  18. chemistry - synthesis of aspirin

    wanted to calculate the theoretical and actual yield of aspirin. mass of salicylic acid = 2.005 g But isn't salicylic acid differ. from acetic acid? If so, how do we find the mass of acetic acid in this experiment volume of acetic anhydride = 4 ml mass of
  19. St Ann's College (DDL) Enugu

    In A Class Of 60 Students, 30 Offer Physcis And 40 Offer Chemistry, (a)Use Venn Diagram To Represent This Information (b) How Many Students Offer Both Subject
  20. chemistry

    What is the theoretical yield of H[2]O (in grams) if 8.3 mol H[2]S were consumed in the above reaction? If 137.1g of water was actually collected after the reaction, what is the percent yield? I have no idea to do this problem. I am not good in math at all
  21. Chemistry

    I've run into some difficulty with my chemistry homework. We went over this practise question in class today as an example. However, I wasn't able to fully grasp how to work it out. "How many grams of nitrogen form when 34.6 grams of nitrogen dioxide
  22. Chemistry

    I keep reading that lead is a poor electrical conductor, but I would like to know the chemistry of why exactly it is a poor conductor.
  23. Chemistry

    Balancing chemistry equations and need help! Thank You!? Help balancing any of the following equations: Cl2+Na Br----> NaCl2 + Br Na+LiOH---->
  24. Math

    For a chemistry experiment, Heather needs 3.75 grams of salt. How many decigrams of salt does Heather need?
  25. Biology

    what are some medicines that help someone sleep. and what is the Chemistry Makeup of those medicines used for sleep and the effect on the brain
  26. Chemstry

    I just copied this because i have a couple more questions on this part.... Sulfuric acid/ Lead Battery: -the electrodes for the battery are composed of Pb(s), PbO2, and/or PbSO4. What are the half reaction occuring at each electrode? include electrolysis
  27. Chemistry Suspension Examples...

    I need 10 examples of household suspensions for science class tomorrow. I got 10 solutions, 10 colloids, and 10 solvents...but can't figure out 10 suspensions! Help! http://www.elmhurst.edu/~chm/vchembook/106Amixture.html Suspensions have much larger
  28. Organic chemistry

    please help me with these what are the functional group(s) in Lexiva (Fosamprenavir Calcium)? i only know that it has an amine group but i'm not sure if there is another group!!! and how can i relate Lexiva to chemistry?(ideas please)
  29. Calculus

    (Chemistry: Wind Chill) At 0℃ the heat loss H (in kilocalories per square meter per hour) from a person’s body can be modeled by H = 33(10√v - v + 10.45) where v is the wind speed (in meters per second). Find dH/dv and interpret its meaning. I am
  30. AP Chem!

    Hey, I have a test tomorrow in ap chemistry on gases. My teacher said that the test would be many open ended questions that are sort of like "explain what happens when a balloon is lowered into 77degrees C of liquid nitrogen and why" Can you guys give me
  31. chemistry

    The decomposition of an aldehyde solution in carbon tetrachloride is a first order reaction with a rate constant of 1.20 x 10-3 min-l. If we start with [aldehyde] = 0.0500 molar, what will the concentration be 150 minutes later? a. 0.00900 M b. 0.0418 M c.
  32. CHEMISTRY

    When doing an ICE Chart in Chemistry, when do you know whether the C is a negative or positive? I was told if the problem gives us reactant concentrations and no product concentration then the reaction goes forward and make the reactant lose and the
  33. Chemistry

    For Chemistry, I have to design a coin. What are some anti-counterfeiting measures I could use to prevent people from replicating it? I've googled this, but I haven't found many good ideas. I can only think of putting grooves on the edge of the coin and,
  34. chemistry

    For the reaction, A = B + C, the rate law is kA]. If it takes 80.0 seconds for 70.0% of a 10.0 gram sample of A to be transformed into products, what is the value of the rate constant? a. 0.00450 s-1 b. 0.0290 s 1 c. 0.00530 s-1 d. 0.0150 s-1 e. 5.40 s-1
  35. Need help on my report on a famous Chemist

    http://www.liv.ac.uk/Chemistry/Links/refbiog.html Would you please help me with my report on a famous chemist, i need ideas on who i should do it on, and i need to identify his/her contributions to my life, and the report has to be one and a half to two
  36. Chemistry

    A sample of nicotine weighing 0.3204 g was vaporized in a flask with a volume of 487 mL. This sample exrted pressure of 74.3 mm Hg at 20 degrees C. What is the molar mass of nicotine? I know this has to do with N=P*V/R*T. and 1 atm=760 mm Hg. Please help
  37. chemistry

    I did a chemistry lab on polarimetry where we separated two enantiomers into individual salts and then used a polarimeter to determine the specific rotation and optical purity. What is the relationship of the proline salts to one another? i said that being
  38. Chemistry HELP!!

    A sample of nicotine weighing 0.3204 g was vaporized in a flask with a volume of 487 mL. This sample exrted pressure of 74.3 mm Hg at 20 degrees C. What is the molar mass of nicotine? I know this has to do with N=P*V/R*T. and 1 atm=760 mm Hg. Please help
  39. Chemistry

    Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -247 B -375 C 191 D -483 Express your answer to three significant figures and include the appropriate units. My answer was 285 kJ/mol
  40. Chemistry

    Balance the equation: NO2- (aq) + Al (s) --> NH3 (g) + AlO2- (aq) (basic solution) ** please note the "2-" on the NO2- and AlO2- are not subscripts, they are the charges. I missed a few classes in Chemistry and find myself lost. I have tried to learn these
  41. Math

    In a class 85% of the student received the highest grade in English Literature, 80% in Math, 75% in History, and 30% in Chemistry. About what percentage of the students could you say for sure that they received the highest grade in all 4 subjects?
  42. Chem 3A

    please help me with this chemistry problem. 1) Write out a balanced chemical reaction equation for the reaction of magnesium with hydrochloric acid, and then What is the Theoretical Yield after balancing the chemical equation?
  43. Chemistry 2

    36.) Suppose a chemistry student discoveres that a block of pure ice is left on her porch as she goes to school one day. What will be the percent composition of the pure ice block?
  44. Chemistry

    You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 6 dollars/hr , and each shift lasts 75minutes . Your laundry requires 6quarters/load. How many shifts must you work if you wish to wash 10 loads of laundry?
  45. lighthouses

    Hi my son has to do a lighthouse for a school project and it has to really light, I'm not really sure how to go about this project or what materials he will need. Can anyone offer any help Believe it or not here is a site on how to build a model
  46. Chemistry

    A 19th-century chemist, Marcellin Berthelot, suggested that all chemical processes that proceed spontaneously are exothermic. True or False? I thought it was true, but then in my chemistry textbook, I could not find this person's name. Can someone verify
  47. Organic Chemistry

    Hello, I'm studying Organic Chemistry in College and in a homework there was an exercise that I could't resolve about aldol condensation of the same molecule. It was like this: What are the possible products of the aldol condensation of 4 molecules of
  48. Chemistry

    Chemistry question: Given: CH4 + 2O2 ~ CO2 + 2H2O C - H = 99 kcal O - O = 119 kcal C = O = 192 kcal O - H = 111 kcal Calculate the change in energy for the CH4 - O2 system.
  49. Biology

    Is there any biology websites for teens??? (NOT games! notes and quizzes to practice). The Science of Biology The Chemistry of Life Cell Structure and Function Photosynthesis & Respiration Something REALLY easy to understand(btw I'm going to the 9TH
  50. Chemistry

    Does anyone know of any sites that make learning to balance equations easy? I just transferred to a new school and the chemistry class is way ahead of my old class. I really don't get it. Please help since there is a test tomorrow and it's on stuff that
  51. chemistry

    can you please give me one practical application of analytical chemistry in being a medical technologist? i know it will determine the separation event happening on the lab test... but is that already a practical application? or i have to cite a deeper
  52. chemistry

    i have to do a "chemistry of cooking" project for my chem class. for the project i need to convert pounds, grams, and ounces into moles, but i do not know how. for example, i need to convert 453.5g of beef into mols. how do i do that? do i need to know the
  53. chemistry

    I have a question in chemistry relating to identifying a compound that would precipitate the iron ions out of a water supply. I am unsure of a compound that would react to produce the iron as a precipitate that could be removed. Thoughts?
  54. Chemistry

    For a chemistry lab, I have to calculate the heat of combustion of paraffin wax. So how would I do that? And for the second part of the lab, I have to calculate the heat of fusion of ice from my data. How would I do that? I'm kind of confused so can I get
  55. DMMS

    Chemistry What characteristics are shared by all alkali metals and alkaline earth metals? A They conduct electricity very well B They are strong and shiny C They form alkaline solutions when mixed with water D They do not react with water at all
  56. chemistry

    which of the following is true regarding the inner transition elements? A. their valence electrons can be located in both s and f sublevels B. They occupy the d block of the periodic table C. These include the lanthanides and actinides and do not have f
  57. Chemistry

    I have 25 million gallons of water at a pH of 6.5. I add 17.4 million gallons of 12.5% by wt sodium hypochlorite (NaClO) at a pH of 12.5 to this water. What will my pH of my final solution be? It's been about 5 years since I took chemistry and I just don't
  58. Chemistry

    Aspirin can be prepared in the chemistry laboratory by the reaction of salicylic acid with acetic anhydride. What volume of acetic anhydride is required to produce one killogram of aspirin assuming 100%yield
  59. math/ chemistry

    so I have this chemistry problem which involves math and basically I need to convert 62 g/mol into mol/L but I don't know how. like do you DIVIDE the g/mol by 1000 to convert g to L? and then how to you get the mol to become the numerator?
  60. Science

    A chemistry teacher needs to prepare 750 ml of a 2.5M solution of Potassium iodide for a lab. How many grams of potassium iodide will be needed to make the solution?
  61. Biology

    How do you balance equations? http://www.chemistry.ohio-state.edu/betha/nealChemBal/ The reactants are written on the left and the products on the right.An arrow pointing towards the product is inserted between the reactant and product.The number of
  62. Chemistry

    Why use Methyl tert-butyl ether in the organic chemistry lab when separating compounds? separating WHAT compounds and how? as a solvent? It has a low boiling point and isn't very reactive, generally, but there may be other specific reasons depending upon
  63. science

    A mixture of benzenoic acid aniline and phenol is dissolved in chroloform and the solution was treated with sodium hydroxide.hydrochloric acid and sodium bicarbonate.show the separation chart,identify the composition of each phase and explain the chemistry
  64. Science

    Sir, I am Raveesh, I have done my M.Sc in Botany and B.Ed in Chemistry and Biology. Now i am working as a Lecturer in a college from last 2 years. I really interested to do online tutoring as a TUTOR / e-tutor. But I don't know how to do? Because I stay in
  65. CHM 312L

    Experiment: Thermodynamics of Real Gases Chemistry 311L (Heat Capacity Ratio and the Joule-Thomson Effect) question: Imagine that you forget that an oil manometer measures pressures above atmospheric. What will happen to your calculated heat capacity
  66. Ap Chemistry

    Posted by Jake on Sunday, September 23, 2007 at 1:08pm. My objective is to find the molar volume of a gas. Is this the correct balanced equation for magnesium ribbon reacting with hydrochloric acid to form hydrogen gas? 2Mg (s) + 2HCL (l) ----> H2 (g) +
  67. Chemistry - HELP IGCSE

    I have a chemistry exam tomorrow and I don't get the double bonding in covalent bonding I tried many websites , textbooks and other books and yet nothing worked Can someone please explain it clearely and in a simple way and please don't put any links for
  68. Math

    Stupid question time. I need to figure out how to rearrange equations to solve for x in my chemistry homework, which involves putting equations in quadratic form first. But I can't for the life of me remember how to "rearrange" them correctly. So what in
  69. chemistry

    So I have to make a green cleaner for a project in chemistry. I think my ingredients should be: vinegar, salt, water, and lemon juice. But I don't know how I would write that exactly as a chemical formula. How could I write a chemical equation if I have 4
  70. Chemistry

    Explain in terms of forces between structural units why H2O2 has a higher melting point than C3H8. Also, which between the two examples has a lower boiling point? NH3 or AsH3 C3H7OH or C2H5OCH3 Can you possibly give me a good website that simply explains
  71. CHEMiSTRY PROJECT

    For chemistry I have to make a comic strip about gold. The comic strip has to included all the important facts i.e. atomic mass, symbol, weight,etc... Any suggestions on what my comic strip could be or any ideas. Thanks ahead for you help.
  72. chemistry

    Effusion/Diffusion Chemistry Help!!! If 4.83mL of an unknown gas effuses through a hole in a plate in the same time it takes 9.23mL of Argon, Ar, to effuse through the same hole under the same conditions, what is the molecular mass of the unknown gas?
  73. chem

    A chemistry lab experiment requires 33.3 g of silver nitrate. How many grams of a 14.1% by mass solution of silver nitrate should be used? _________g Solution
  74. Chemistry

    according to the bohr model of the hydrogen atom, what is the closest an electron can get to the nucleus? What is the farthest it can get from the nucleus? ( if the latter answer seems absurb, it might amuse you to know that it is the same value predicted
  75. chem

    how many grams of sulfur are needed to react w/ 246 grams of mercury to form HgS? Hg + S ==> HgS unless your instructor insists on writing S as S8, in which case it will be 8Hg + S8 ==> 8HgS. The answer will be the same no matter which way the equation is
  76. statistics and probabilities

    Suppose you will be taking exams in English, statistics and chemistry tomorrow and from past experience you know that for each exam you have a 50% chance of receiving an A. List all the possibilities for receiving A's on various exams. Letting X represents
  77. PSYCH/SOCIOLOGY!!!

    Should I take psychology before sociology or take sociology before psychology. Like saying "You can't do well in chemistry unless you finish biology"
  78. oscotech

    chemistry: is the formula to be used @ 25 degree c is E=Eo -(0.059/n(log a)) or Eo+(0.059/n)(log a)
  79. Chemistry

    Hello, we recently did a lab in our chemistry class to analyze an Unknown amount Calcium Carbonate which was titrated with EDTA. Our titration results were: mass of the unknown CaCO3 was 0.172 g and the mL of EDTA added was 30.7. How do I find the percent
  80. Chemistry

    I'm doing a lab in chemistry and I need help with a question, here is my data: Mass Before: 26.4 g After burned: 26.25 g Total Mass burned: .15 g 1. Calculate the mass of oxygen that was consumed while the candle burned. I think I need to use mole
  81. chem

    Assuming the volumes are additive, what is the [Cl-]solution obtained by mixing 210mL of 0.600M KCl and 630ml of 0.385M MgCl2 ? Responses chemistry - bobpursley, Friday, September 19, 2008 at 4:20pm You have to assume each chloride is soluble. How many Cl
  82. AP Chemistry

    In a fit of boredom, a chemistry teaching assistant swallows a small piece of solid dry ice (CO2). The 8.9 g of dry ice are converted very quickly into gas at 311 K. Assuming the TA’s stomach has a volume of 1.5 L, what pressure is exerted on his
  83. Science

    What were Mendeleev's reversals?How did Henry Moseley explain them? Mendeleev thought the periodic table was in order of atomic mass. Mosley determined that atomic number was the correct order. http://www.chemistry.co.nz/henry_moseley.htm
  84. Chemistry

    Hi Dr. Bob, I am quite stumped on how to figure out when chemical equations have a REACTION or NO REACTION. I have read the material in my textbook and even took out a chemistry books for the "Utterly Confused" to try to figure this out. Example: Zn(s) +
  85. Chemistry

    Hi there, can someone please help me with this chemistry problem? Write the equation for the acid-base reaction that takes place when nitric acid (HNO3) dissolves in H2O. (Include the phase of each substance.) I got HNO3(aq) + H2O --> H3O+(aq) + NO3−(aq)
  86. Chemistry

    In an organic chemistry lab, why is the organic layer usually the upper layer in the separatory funnel while the aqueous layer is usually the bottom layer?
  87. organic chemistry

    a careless organic chemistry student was performing "competing nucleophiles in nucleophilic substitution reactions" experiment , and left his container of tert-butyl chloride and tert-butyl bromide open to the air for several hours. what happened to the
  88. Coordination Chemistry

    A particular metal ion octahedral complex has the same number of unpaired electrons (non-zero) whether the complex uses weak or strong field ligands. List several fourth period transition metal ions that could have this behavior. Also, if someone could
  89. cHEMISTRY

    GIVE THE EMPIRICAL FORMULAE OF THE HIGHEST HYDRIDE AND HIGHEST FLUORIDE OF UNUNHEXIUM, EXPLAINING HOW YOU ARRIVED AT YOUR CONCLUSIONS Here is the web site for a very good periodic table. Look for element #116, Uuh. Elements in the periodic table have
  90. sat essay

    please give me some advice. thank u! assignment:Is the way something seems to be not always the same as it actually is ? Most people tend to consider what they see as facts or truth. As far as I am concerned, what we see is sometimes conceiving and
  91. sat essay

    please give me some advice. thank u! assignment:Is the way something seems to be not always the same as it actually is ? Most people tend to consider what they see as facts or truth. As far as I am concerned, what we see is sometimes conceiving and
  92. soil chemistry

    Can someone please help me answering this question regarding soil chemistry? A sandy soil has a CEC = 5 meq/100g and a K saturation = 6%. An alfalfa crop yields 5 ton/ac/yr at 3% K. Calculate initial exchangeable K and estimate final exchangeable K. Where
  93. Chemistry

    Hi, I have few questions from a chemistry lab that i did, 1) I'm not sure whats the point of heating a nitrate (NaNO3) 2) I'm not sure why you add NaOH to NaNO3 after it has dissolved in water 3) I'm not sure why do we have to test what gas is produced
  94. Chemistry

    I have a Chemistry question which should be very simple but I do not know what significant figures are. Assuming the following numbers are measurements and using the rules for significant figures, determine the answer for the following calculation.
  95. Physical Chemistry Help!

    I am posting a link to the jpeg file of the physical chemistry homework i need help with, because everytime I try typing it out, I just get wierd symbols. If somebody could please help, that would be greatly appreciated! Thanks~ =) img.photobucket. com/
  96. Chemistry

    When 155 mL of water at 26 degrees Celsius is mixed with 75 mL of water at 95 degrees Celsius, what is the final temperature of the mixture? (d Water = 1.00 g/mL) Im really stuck on this problem and chemistry isnt exactly my strong point, thanks in
  97. For DrBob222

    the chemistry question: v=0.465L T=559.15K P=112.496 kPa Pv/t = Pv/t 112.kpa(0.465)/559.15 = (x)(0.464428)/(247.8) x= 49.9 kPa ...i skipped conversion steps, but i'm pretty sure i did those right..
  98. Chemistry+balancing equation tips

    We are on combustion reaction at the moment in chemistry, and I have to say, these reactions are like extremely hard to balance(well, just alot of erasing). It takes me a while to balance combustion reactions and I want to know if theres any tips in
  99. Science

    What means Cells in Science? It depends on the context: In electricity, or chemistry, cells are sources of electrical energy. In life science, cells are the basic unit of construction for animal or plant life.
  100. Ap Chem,

    1) What kind of chemistry makes it possible for DNA of materials being tested to lodge at only one kind of probe molecule? 2) What is normally the connection between damage to a cell and the p53 protein? 3) From the perspectives of the society as a whole,

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