1. organic chemistry laboratory

    hi, im not sure if all my answers are correct especially number 5. could any one check and tell me? please and thank you. 1. Why is it important to have clean test tubes before running a test? Before which tests should acetone not be used to clean the test tubes? Due to ...
  2. Chemistry

    Can someone check my answers please? I had specific trouble with 7, 13, and 27 (I'm pretty sure my other answers are correct; some reassurance would be nice though). And I have a small question about 8. 1. The ΔHf of an element in its standard state is defined to be 0 kJ/...
  3. language arts

    John Yinger thinks that the natural-born clause should be removed because (1 point)it makes international policy more difficult. it goes against a central principle of American democracy. it damages the relationship between American citizens and immigrant communities. 2. What ...
  4. Chemistry

    I don't really understand these questions and their processes. And I am a bit iffy on redox reactions. For problem 3, can you show a step by step process how to do the problem? Problem 2, I do not fully understand how to do it at all. How would you know the resulted products? ...
  5. Chemistry(Please check answers)

    1) The standard molar entropy value of N2 (g) is 191.5 J/K-mol, of O2 (g) is 205.0 J/K-mol and of NO2 (g) is 240.0 J/K-mol. From these values we can calculate the Delta So for the reaction N2 (g) + 2 O2 (g)-> 2 NO2 (g) to be? I did products - reactants (240 X 2) - [191.5...
  6. Finite math

    A bank account pays interest at 12% compounded monthly, and has a monthly fee of $10, deducted at the end of each month. If $13,000 is deposited on January 1, 2013, how much is in the account on January 1, 2016? I have done some question related to compound interest however ...
  7. Chemistry

    My ONLY three questions I need help on! I did the other 50 something already!(: Why are covalent bonds weak in the presence of heat but strong in the presence of water? What are the 5 rules for ionic bonding? Give an example of a compound that is representative of each rule. ...
  8. contemporary math

    Compute the amount of compound interest earned in 1 year for an investment of $1,000,000 with a nominal interest rate of 8% compounded quarterly. Then Compute the Annual Percentage Yield (APY) for the investment in the previous question. (Round APY to the nearest hundredths of...
  9. business math

    . Compute the amount of compound interest earned in 1 year for an investment of $1,000,000 with a nominal interest rate of 8% compounded quarterly. Compute the Annual Percentage Yield (APY) for the investment in the previous question. (Round APY to the nearest hundredths of a ...
  10. Statistics

    Across the USA, results for these exams are normally distributed. What does that mean and why is this the case? If you were to create a histogram of all GRE scores, what would you expect the histogram to look like? Would it be symmetrical? Would it be bell shaped? How many ...
  11. Chemistry

    A compound D, CH3CHCLCH2CH3 was boiled under reflux for some time with dilute NaOH solution.. Dilute nitric acid was then added to the mixture, followed by dilute silver nitrate solution. A Few drops of concentrated ammonia solution were then added. What observation were ...
  12. chemistry

    2 questions please: The highest positive oxidation number that chlorine can exhibit an any compound is +7, whereas its most negative oxidation number is -1. Write the electron configuration of chlorine and explain why these are limiting oxidation numbers for chlorine. Indicate...
  13. Math

    Here is the question on compound interest. It is not graded, but is bugging me because I can't figure it out. After the third year, $2662 was in Samantha's account. If the account continues to earn 10% interest, how much money will be in the account (1)after the tenth year and...
  14. Chemistry

    You have synthesized a substance from aqueous solution that has a melting point of 152 °C. A pure authentic sample of the intended product has a melting point of 154 °C. The most likely explanation for the difference in melting temperature is that the your product is impure...
  15. chemistry 1

    if 20.2g of zn react with and equal amount of magnesium chloride to form magnesium and zinc chloride[zn+mgcl2> mg+zncl2] a.what is the limiting reactant? b. how much magnesium will be produced? Here is the way to solve most of these stoichiometry problems. Step 1. Write the...
  16. Chemistry

    Given 2Al2O3 (s) --> 4Al(s) + 3O2 (g) (standard enthalpy change= 3351.4 kJ) a) What is the heat of formation of aluminum oxide? How do I find heat of formation from standard enthalpy change? I know how to do it when I'm given enthalpy, but they aren't the same thing- ...
  17. Chemistry

    How can you increase the concentration of the product (s) in each of these reactions by varying the temperature and pressure (caused by volume change)? 4NH3 + 5O2 <=> 4NO + H2O Delta H = -903.75 kJ Br2 + Cl <=> 2BrCl Delta H = 14.64 kJ Please help... With gaseous ...
  18. Chemistry

    Combustion of natural gas (primarily methane) occurs in most household heaters. The heat given off in this reaction is used to raise the temperature of the air in the house. Assuming that all the energy given off in the reaction goes to heating up only the air in the house, ...
  19. Chem Very Urgent

    if 4.55 g of sodium sulphide and 15.0 g of bismuth nitrate are dissolved in separate beakers of water which are then poured togehter, what is the maximum mass of bismuth sulphide an insoulble compound that could precipitate? Which reactant was the limitting reactant? Na2S + Bi...
  20. Science asap

    Which organisms are capable of converting gaseous nitrogen in the air into a form that other living organisms can use? nitrogen-fixing bacteria denitrifying bacteria decomposers producers Which step in the nitrogen cycle is accelerated at the beginning of the eutrophication ...
  21. chem

    I have to balance an equation and I had to make the equation from an experiment we did. So far, my equation looks like this and I know what I have is correct: Cu(NO3)2+H20+NaOH----->Cu(OH)2 I think I probably need an N or a Na on the right side. What do you think? You don't...
  22. Chem.....

    Methanol, CH3OH, is produced on an industrial scale from carbon monoxide and hydrogen. At the temperatures used, gaseous methanol is formed according to the following thermochemical equation: CO(g)+ 2H2(g) <---> CH3OH(g) H = -90Kj 1. State Le Chateliers principle and ...
  23. chemistry

    what experimental difficulty would you encounter if you had neglected to include a drying step before evaporating the ether solution of the neutral organic compound? Water was added to the organic solvent ,but a drying agent wasn't added. So would the difficulty be a ...
  24. algebra

    i did not get a response so i am rewording question . please help if you can. thanks ann store A charges 9.75% tax store B charges 7.25% tax If a shopper's pre tax receipt is between $11.57 and $81.43, write a compound inequality that describes the difference in taxes paid for...
  25. Chemistry Problem

    A student proposes to use visible spectroscopy to measure the kinetics of the permanganate/oxalic acid reaction. The initial permanganate solution was very dark. For a 1 cm sample cell, the absorbance A = 2,500[MnO4]. As a practical rule of thumb, Beer's law is only accurate ...
  26. Chemistry

    Help with lab report Need Help finishing my lab report.KNOWN VALUES ARE V OF HCL=50ML,M=2.188.V OF NAOH=55.3ML,M=2.088.INTIAL TEMP FOR HCL=22.5C,NAOH IS 23C.this is for part A: Mass of final NACL solution assuming that the density of a 1 M Nacl solution is 1.04 g/ml? Heat ...
  27. math

    sam invested $5000 in a GIC earning 8% compound interest per year, the interest gets added to the amount invested, so the next year sam gets the interest on the interest already earned , as well as on te original amoun, how much will sam's investment be worth at the end of 10 ...
  28. chemistry

    4NH3(g)+5O2(g) yield 4NO(g)+6H2O(g) Deduce the equilibrium constant expression for the reaction.
  29. Science

    How would you prove that sodium hydroxide is a base without using a litmus paper to test? Give the equation for the reaction?
  30. Chemistry

    How much work (in J) is involved in a chemical reaction if the volume decreases from 5.00 to 1.26 L against a constant pressure of 0.857 atm?
  31. chemistry

    write and equation for the reaction of triethylamine and water. does the eqilibrium go to the right or left. so far what I have is C6H15N + H2O but I'm not sure of the products
  32. chemistry

    what is the volume in liters in H2gas produced at 24 degree celsius and 835 mmhg from the reaction of 12g of many thanks
  33. Chemistry

    Write the equation for the reaction by which aspririn decomposes in an aqueous ethanol solution. C9H8O4 + C2H6 --> ?
  34. CHEM-HELP!!!!

    8. 2(NH4)3PO4--> 3N2+ O2+ 12H2+ 2PO3 a)name products b)Name the reactant c)type of reaction this is the only info that is given///thank you
  35. Science

    How does Exothermic and Endothermic reactions affect the rate of a reaction? Please help. I need something that will be easy for me to understand and adopt into my own words. Thank You :)
  36. Chemistry

    A reaction at 3.24 atm consumes 5.10 L of a gas adiabatically (q = 0). Calculate the change in internal energy of the system (in kJ).
  37. ap chemistry

    Consider the reaction 2 Al2O3(s) -> 4 Al(s) + 3 O2(g) . H = +3339.6 kJ/mol How much heat is generated when 0.455 L of a 3.60 M Al solution reacts with 1.05 mole O2 ?
  38. HCA/220

    how does blood clotting, immune response, allergic reaction and hormone resonse relate to each other
  39. Chemistry

    Hydrofluoric acid etches glass by reacting with the silica in it according to the following equation. H° = 54.5 kJ and S° = 436.5 J/K Calculate G° at 25°C for this reaction.
  40. chemistry

    If the initial concentration of AB is .250 M, and the reaction mixture initially contains no products, what are the concentrations of A and B after 75s?of XY after 5.0 X10^1s?
  41. Chemistry

    Determine how many milliliters of 0.448 M HClO4 will be required to neutralize 38.30 g Ca(OH)2 according to the reaction: 2HCl+Ca(ClO4)2+2H20
  42. Chemistry

    Enter the net ionic equation, including phases, for the reaction of AgNO3(aq) with BaO(aq). Is it... Ag+O2--->AgO?
  43. chemistry

    What assumption did you make about the reaction of KMnO4 solution in those determinations where temp didn't change to allow k to be a constant?
  44. Chem 104

    The reaction of 2.30g N2 with excess H2 produces 2.00g NH3. The percent yield of this reaaction is?
  45. Science PLEASE HELP

    How does Exothermic and Endothermic reactions affect the rate of a reaction? Please help. I need something that will be easy for me to understand and adopt into my own words. Thank You :)
  46. chemistry

    Ca(s) + Br2(l) --> CaBr2 is synthesis my teacher also said that the cause of the reaction is stable electron configuration is that the same thing as the electrolytes one
  47. College Chemistry Really Need Help

    THE EQUILIBRIUM CONSTANT FOR A REACTION IS 2.48 AT 25 DEGREES CELSIUS. WHAT IS THE VALUE OF ΔG°(KJ)AT THIS TEMPERATURE? (R=8.314 J/K mol)
  48. chemistry

    what mass of salt can be produced from the reaction of 3.45 grams of sodium hydroxide and an excess of hydrochloric acid?
  49. Chemistry 1002

    Calculate the standard entropy change for the following reaction at 25 °C. 2 Al (s) + 3 ZnO (s) --> Al2O3 (s) + Zn (s) answer is in J/K mol
  50. Science

    Which reaction is exothermic? A. Cellular respiration B. Photosynthesis C. Baking soda + vinegar D. Melting Ice***
  51. Chemistry

    I have to write the rate law for two elementary reaction equations A ) 2a+b>c+d B ) X+Y>Z I'm pretty sure it's just k[ A ][ B ] and k[ X ][ Y ] but does the coefficient affect it in this case? is it [ A ]^2 ?
  52. College Chemistry

    For a certain first-order reaction the rate constan is 2.9 s-1. what is the fraction of the reactant remaining after 4 half lives?
  53. Chemistry

    When the oxidation-reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag^+ + Cu = Ag + Cu^2+
  54. Chemistry

    Identify the Bronsted-Lowry acid in the following reaction. H2O (l) + HCO31- (aq) → H3O+ (aq) + CO32- (aq)
  55. Chemistry

    When the equation for the following reaction in basic solution is balance, what is the sum of the coefficients? MnO2 + HO2^1-.....>MnO4^1- A=11 B=31 C=14 D=9
  56. Chemistry

    How many grams of PI3 could actually be produced from 250 g of I2 and excess phosphorous if the reaction gives a 98.5% yield? P4 + 6I2 --> 4PI3
  57. physics

    if the reaction time is 10.0s, how far will the car travel before hitting the brakes? Vf = 27.42 m initial speed = 80 km/hr coefficient of friction = 1.00
  58. Chemistry

    The half-life (t1/2) of a first order reaction is 0.100 s. What is the rate constant? a. 6.93 s-1 b. 0.693 s-1 c. 0.0693 s-1 d. 0.144 s-1 e. 3.01 s-1
  59. chemistry

    Ca + Br2 --> CaBr2 its synthesis and the reason the reaction happens is stable electron configuration but i don't understand why.
  60. Chemistry

    Write the net ionic equation for the precipitation reaction between ammonium sulfide and cadmium nitrate.
  61. Chemistry

    Write the net ionic equation for the precipitation reaction between ammonium sulfide and cadmium nitrate.
  62. Chemistry

    Write the net ionic equation for the precipitation reaction between ammonium sulfide and cadmium nitrate.
  63. chemistry

    what is the gas formed when baking soda is added to vinegar? complete the reaction: NaHCO3(s) + CH3COOH(aq)
  64. Chemistry

    I have to write the rate law for two elementary reaction equations A ) 2a+b>c+d B ) X+Y>Z I'm pretty sure it's just k[ A ][ B ] and k[ X ][ Y ] but does the coefficient affect it in this case? is it [ A ]^2 ?
  65. Chem 11

    How many grams of O2 are required to produce 255grams of SO2 in following reaction? 4FeS2+11O2===> 2Fe2O3+8SO2
  66. ochem

    For a Grignard reaction, if you start with 3.97 mL of pure bromobenzene and 0.733 g of 1-phenylethanone, what is the theoretical yield of 1,1-diphenylethanol? Please help.
  67. Chem Help Please!

    Give the full mechanism for the reaction of 1-bromo-3-methylpentane with methanol. I know you cant draw on here. but can you tell write it out with words? Thanks!
  68. SCIENCE

    CAN WE USE A COPPPER VESSEL FOR STORING 1 MOLAR AgNO3 SOLUTION? IF NO JUSTIFY BY GIVING CHEMICAL REACTION BETWEEN THEM
  69. chemistry

    explain inside a flashbulb are the 2 reactants necessary for a violent reaction that produce light yet they don't react..
  70. grade 12 chem

    use the activity series to predict if a reaction will occur, complete and and balance your equation. Zn(s)+ Cu(NO3)2
  71. Chemistry

    What amount of ammonium sulfate is produced by the reaction of 8.48g of ammonia with 24.50g sulfuric acid?
  72. Gen Chem

    n = 6 and E° = 0.011v for a redox reaction with Q = 7.03 x 10-1. Calculate E. Assume T = 298.15K. How do I set this equation up?
  73. Gen Chem

    What is n, the number of moles of electrons transferred, in the following reaction? 2 MnO4-(aq) + 16 H+(aq) + 10 Cl-(aq) ===> 2 Mn2+(aq) + 5 Cl2(g) + 8 H2O(l).
  74. Chemistry

    Please help me answer the question: What does it mean Write a net ionic equation for the reaction 2HCl + Ca(OH)2 -> CaCl2 + 2H20
  75. Chemistry

    If a reaction quotient is undefined, and the Kc = 1. A+B=>C A=0m, B=0m, C=10m What happens to the concentrations of A,B,C? do they decrease or increase or no change to reach equil?
  76. Chemistry

    A chemist ran the reaction and obtained 5.70 of ethyl butyrate. What was the percent yield? How do I solve this problem?
  77. Chemistry

    Identify the acid or base behavior of each substance in this reaction: H2PO4 + H2O <----> H3O+ + HPO4-
  78. chemistry

    Determine how many milliliters of 0.255 M HClO4 will be required to neutralize 48.56 g Ca(OH)2 according to the reaction: 2HClO4(aq)+Ca(OH)2(s)=CA(ClO4)2(aq)+2H2O(l)
  79. chemistry

    If 2.00g of Zn is allowed to react with 1.75g of CuSO4, how many grams of Zn wil remain after the reaction is complete?
  80. Chemistry- Please Help!!

    Predict the proper equilibrium constant expression for the following reaction... Fe(OH)3(s) ----> Fe3+(aq) + 3 OH-(aq) Explain the reasoning behind your answer.
  81. Chemistry

    Which of these is best described as an acid-base reaction? KCl + NH4NO3 = KNO3 + NH4Cl NH3 + H2O = NH4 + OH
  82. Chemistry

    Complete the following chemical reaction. Label any precipitate that forms. KCl(aq) + AgNO3 (aq) ¨KNO3 (aq)+AgCl(s)
  83. Chem H

    How do you write a balanced net ionic equation for the reaction Cr2(SO4)3(aq)+(NH4)2(CO3)(aq)?
  84. Science HELP!

    The body's reaction to information is to send these to the brain. A. Neurons B. Impulses C. Dendrites D. Synapse Is the answer B? Thanks
  85. chemistry

    Please help again. How many grams of lithium are required to completely react with 70.7 mL of N2 gas at STP when given the following reaction: 6Li + N2 = 2Li3N
  86. Chemistry

    Which of these is best described as an acid-base reaction? KCl + NH4NO3 = KNO3 + NH4Cl NH3 + H2O = NH4 + OH
  87. chemistry

    find mass of sulfuric acid obtained in reaction of 20.0g if sulfur trioxide with excess of water
  88. chemistry

    Which of the following is true for the gas phase reaction shown below? 4NH3(g) + 5O2(g) ¨ 4NO(g) + 6H2O(g), ƒ¢H = -0.905 kJ
  89. Chemistry

    how many moles of silver nitrate are required to react with 24.8 mL of 1.15M calcium chloride in a metathesis reaction Thanks!
  90. Chemistry

    Formic acid is only readily soluble in water and in both 0.6 M NaHCO3 and 2.5 M NaOH. give a brief explanation of the reaction for each
  91. chemistry

    Phosphorus (p4) burns in the air to give diphophorus pentoxide. what is the blance chemical equation for the reaction
  92. chemistry

    HOw many calories of heat were produced by the reaction of 10ml water with the powder of two compartments (2x3.23 g) of the heater?
  93. Chemistry

    Which of these is best described as an acid-base reaction? KCl + NH4NO3 = KNO3 + NH4Cl NH3 + H2O = NH4 + OH
  94. Chemistry

    Sulfur Trioxide can be dissolved to form sulphuric acid. But it is avoided since the reaction is violent. Explain why?
  95. chemistry

    if a reaction vessel contains 11.5g NH3, 12.0g O2, and 10.5g CH4, what is the maximum mass in grams of hydrogen cyanide that could be made?
  96. Chemistry

    Which of these is best described as an acid-base reaction? KCl + NH4NO3 = KNO3 + NH4Cl NH3 + H2O = NH4 + OH
  97. Chemistry

    Write the net ionic equation for the precipitation reaction between ammonium sulfide and cadmium nitrate.
  98. Chemistry

    How many grams of dichloromethane result from reaction of 2.62 kg of methane if the yield is 43.5 %? CH4+2Cl -> CH2Cl2+2HCl
  99. Chemistry

    Calculate the grams of NaNO3 required to produce 5L of oxygen at STP if the percent yield of the reaction is 78.4%?
  100. chemistry

    For the following reaction, identify the substances oxidized, reduced and the oxidizing and reducing agents? 2SO2 + O2 --> 2SO3
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