1. Chemistry

    The reaction of iron and water vapor results in an equilibrium reaction, 3 Fe(s) + 4 H2O(g) ¡ê Fe3O4(s) + 4 H2(g) and an equilibrium constant of 4.6 at 850¡ÆC. What is the concentration of Hydrogen present at equilibrium if the reaction is initiated
  2. Chemistry

    There's reaction involving gas: Fe + H2SO4 -> Fe2(SO4)3 + H2O + SO2 How Fe2(SO4)3 is occur? I know the "2" comes from the ion of SO4, but I don't know where the "3" comes up. Is the Fe2(SO4)3 comes up from half-reaction method? Is the reaction occurs in
  3. Organic Chem

    A 20 g mixture containing 95% (by weight) of A and 5% of B is recrystallized in toluene (b.p. 110 C). Solubility for compound A is 1.5 g @20 degrees and 10 g @ 110 degrees. For compound B solubility is 0.5 g @20 degrees and 8 g @ 110 degrees. What amount
  4. Chemistry

    Predict the product(s) for the following reaction: H2SO4(aq) + KOH(aq) --> Choose one answer. a. K(s) + H2(g) + SO3(g) b. K2SO4(aq) + H2O(l) c. No reaction occurs d. K2S(aq) + H2O(l) e. KSO4(aq) + H2O(l) I keep getting: K2SO4(aq) + 2H2O(l) which isn't
  5. chemistry

    3. When a mixture of 10.0 grams of acetylene (C2H2) and 10.0 grams of oxygen (O2) is ignited, the resulting combustion reaction produces CO2 and H2O. A) Write a balanced equation for this reaction. B) What is the limiting reactant? C) How many grams of C2,
  6. Chemistry

    For the reaction 2CO2(g) + 5H2(g)C2H2(g) + 4H2O(g) H° = 46.5 kJ and S° = -124.8 J/K The standard free energy change for the reaction of 1.75 moles of CO2(g) at 328 K, 1 atm would be ___ kJ This reaction is (reactant, product) ____ favored under standard
  7. Chemistry

    Consider the following reaction occurring at 298K BaCO3(s)-> BaO(s) + CO2 (g) show that the reaction is not spontaneous under standard condition by calculating delta G rxn. I calculated delta G and got 219.7 kJ, now the question asks if BaCO3 is placed
  8. chemistry, science

    Carbon is also removed from the atmosphere during the process of weathering. carbon dioxide combines with water to form carbonic acid. this reacts with calcium silicate (in rocks) to produce calcium ions, bicarbonate ions and silicon dioxide (silica) the
  9. chem -repost for bobpursley

    Posted by polkadot on Friday, April 8, 2011 at 8:46pm. Can someone please help me by explaining and correcting me? 1) A 0.057M solution of a weak acid has a pH of 4.93. Determine the ionization constant, Ka, of the acid. a) 2.1 x 10^-4 b) 2.4 x 10^-9 c)
  10. Statistics

    Use the Empirical Rule to find what two values 95% of the data will fall between for a data set with a mean of 294 and standard deviation of 13.
  11. CHEM

    A 7.5 g sample of Cu(NO3)2.nH2O is heated. After the water has been driven off, 5.8 g of Cu(NO3)2 remains. What is the value of n in the empirical formula of this hydrate?
  12. Social and Behavioural Sciences

    I'm not sure how to define these words. 1) moral authorities 2) systematic empirical research 3) scientific research
  13. Chemistry

    How do I do the empirical formula for 37.01% carbon, 2.22% hydrogen, 18.50% nitrogen, and 42.27% oxygen? My teacher gave me the answer (C7H5N3O6), but I can never get that answer.
  14. chemistry

    The formula of benzine and organic solvent is C6 H6. what is the empirical formula express the mass of a mole of materials in gram
  15. chemistry

    Benzene has the empirical formula CH and an experimental molar mass of 78 g/mol. What is its molecular formula? Explain how you got your answer.
  16. Chemistry

    What is the molecular formula of a molecule that has an empirical formula of CH2O and a molar mass of 120.12g/mol?
  17. Chemistry

    Consider the decomposition of barium carbonate: BaCO3(s)= BaO(s) + CO2(g). Using data from Appendix C in the textbook, calculate the equilibrium pressure of CO2 at 298K.
  18. Calc Help Please Again Last one!

    Write out the form of the partial fraction decomposition of the function appearing in the integral: integral (6x-58)/(x^2+2x-63) Determine the numerical values of the coefficients, A and B, where A <= B A=? B=? Thank you guys so much! =)
  19. Stoichiometry

    In the decomposition of 2.5 moles of Chromium Hydroxide how many moles of water are produced? Please be VERY descriptive on how to do this. I've been out of school a very long time and am expected to take a test on it tomorrow.
  20. Chem8

    The decomposition of XY is second-order in XY and has a rate constant of 0.00895 M-1s-1 at a certain temperature. If the initial concentration of XY is 0.194 M, how long (in seconds) will it take for the concentration to decrease to 0.047 M?
  21. Chem10

    The decomposition of XY is second-order in XY and has a rate constant of 0.00599 M-1s-1 at a certain temperature. If the initial concentration of XY is 0.174 M, how long (in seconds) will it take for the concentration to decrease to 0.054 M?
  22. Science

    Can an element be separated to form a compound? Can an element form a compund? I think it's a yes to both of the above questions. An element can form a compound by combing with another element.
  23. chemistry

    If a sample of a compound of carbon and oxygen contains 3.00g of carbon and 8.00g of oxygen, what is the mass percent of carbon in the compound? A. 27.3% B. 25.0% C. 37.5% D. 3.67% E. 2.67%
  24. ap chemistry

    When 0.515 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.243◦C is observed. What is Urxn for the combustion of compound X? The hardware component of the calorimeter has a heat capacity
  25. stoichiometry

    A confiscated white substance, suspected of being cocaine, was purified by a forensic chemist and subjected to elemental analysis. Combustion of a 50.86-mg sample yielded 150.0 mg CO2 and 46.05 mg H2O. Analysis for nitrogen showed that the compound
  26. Chemistry test can't fail please help (senior)

    1.Cell respiration glucose is reacted wth oxygen in body to produce carbon dioxide and water how many liters of carbon dioxide would be produced if 90.0 g of glucose completely reacts with oxygen C6H12O6(s)+ 6O2(g) -> 6H2O(g) + 6CO2 (g) How many liters
  27. If you answer these questions I will pass this cla

    1.Cell respiration glucose is reacted wth oxygen in body to produce carbon dioxide and water how many liters of carbon dioxide would be produced if 90.0 g of glucose completely reacts with oxygen C6H12O6(s)+ 6O2(g) -> 6H2O(g) + 6CO2 (g) How many liters
  28. Chemistry

    True and False... 1. A thermodynamically favorable reaction also proceeds spontaneously. I think that it is false? 2. Doubling the concentration of a reactant always causes the reaction rate to double. 3. a reaction that has a large activation energy in
  29. Chemistry-confused

    I am rather confused. Is sand considered a mixture or a compound? Some have said it is a compound because it is silicon dioxide. Others have said it is a mixture because it is impure silicon dioxide. So...?
  30. Chemistry

    1a). If you react 16 mol A with 15 mol B in the reaction 4A + 3B → 2C, what is the limiting reactant? 1b). What is the theoretical yield of product C in mol? 3a.) If Pb(NO3)2 were the limiting reactant in this reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s)
  31. Science

    When determining the formula for a compound, it is important to know the valence numbers of each element. Suppose that "element A" has a valence number of 3 and "element B" has a valence of 2. If the two elements combine, then when writing the formula for
  32. Chemistry

    The mineral cassiterite is a compound of tin and oxygen. Chemical analysis of cassiterite shows that the mass percentages of tin, Sn, and oxygen, O, are 78.8% and 21.2%, respectively. Determine the formula of this compound. I found the molar mass and
  33. chemistry

    A mixture of hydrogen peroxide, H2O2, and hydrazine, N2H4, can be used as a rocket propellant. The reaction is: 7 H2O2(g) + N2H4(l) ® 2 HNO3(aq) + 8 H2O(l) a) How many moles of H2O2 react with 0.477 mol N2H4? [1] ___________ b) How many grams of HNO3 can
  34. Chemistry

    can anybody think of a reaction that involves benzyl acetate? formula is CH3COOCH2C6H5 i already have most of the synthesis's but i really need a reaction that involves this ester as a reactant NOT a product. thanks :) Why don't you just cleave the ester
  35. chemistry

    A proposed mechanism for a reaction is: (i) A + B2 = AB2 Ea1 = 12 kJ/mol ƒ´H1 = 3 kJ/mol (ii) AB2 + C2 = ABC + BC Ea2 = 30 kJ/mol ƒ´H2 = 5.2 kJ/mol (iii) ABC + B2 = AB2 + BC Ea3 = 10 kJ/mol ƒ´H3 = -7.8 kJ/mol a) Which is the rate determining step?
  36. Chemistry

    I'm sorry here is another I do not understand. How do you find out exactly how much of a solution you would need to completely precipitate another compound in the reaction? We can precipitate out solid lead(II) iodide from an aqueous lead(II) nitrate
  37. Chemistry URGENT! I really need help!

    Consider the following reaction occurring at 298K BaCO3(s)-> BaO(s) + CO2 (g) show that the reaction is not spontaneous under standard condition by calculating delta G rxn. I calculated delta G and got 219.7 kJ, now the question asks if BaCO3 is placed
  38. Biology Help

    Enzymes: a. increase the amount of energy release in a reaction b. decrease the amount of energy release in a reaction c. catalyze only redox reactions d. reduce the activation energy needed to for a reaction I think its d. or a. Help Please
  39. science-CHEM

    Fe+3 + SCN- ==Fe(SCN)+2 if adding NaOH will form precipitates, but what is the precipitates' formula? And after this reaction, if we add HCl to the reaction, will the precipitates dessolve? What does the HCl affect the reaction? THX
  40. Chemistry

    Can you have one half-reaction take place, without the other half-reaction taking place immediately? The other half-reaction takes place when the cell potential is raised. I half witness this in some electrochemical cells. Sincere Thanks.
  41. Chemistry

    3. An electrochemical reaction occurs between an unknown element and zinc. The half-cell reaction for the zinc is: Zn(s) → Zn2+(aq) + 2e− The cell potential for the reaction is Eºcell = 1.83 V. a. Is the reaction spontaneous or nonspontaneous?
  42. Chemistry

    Which of the following can we predict from an equilibrium constant for a reaction? 1 The extent of a reaction 2 Whether the reaction is fast or slow 3 Whether a reaction is exothermic or endothermic a. 1 only b. 2 only c. 3 only d. 1 and 2 only e. 1 and 3
  43. chemistry

    When 0.572 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.461 ◦ C is observed. What is ∆Urxn for the combustion of compound X? The hardware component of the calorimeter has a heat
  44. chemistry

    Which of the answer choices correctly describes an action that will increase the solubility of a solid solute in water? cool the solution increase the pressure heat the solution decrease the pressure Examine the statement. The energy required to break the
  45. Chemistry

    Which of the following pairs of atoms would you expect to combine chemically to form an ionic compound? A.Li and S B.O and S C.Al and O d.F and Cl e.I and K F.H and N Which of the following pairs of elements will not form ionic compound. a.sulfur and
  46. chemistry

    A student prepared a column of alumina and was able to purify a compound by passing the compound dissolved in diethyl ether through the column. In this example, diethyl ether is the ??? phase and the alumina is the ???? phase
  47. chemistry

    Which of the following statements is true about the nucleus? Only the strong nuclear force holds the nucleus together. The strong nuclear force and the residual strong force hold the nucleus together. The presence of neutrons, the strong nuclear force, and
  48. Science (Chemistry)

    A chemical system within a sealed 1 L reaction vessel is described by the following reversible reaction equation: 2H2S(g) <---> 2H(g) + S2(g) If the equilibrium constant is 0.000 004 200 at 1103 K find: (a) the reaction quotient intially (b) the
  49. chemistry

    What is the empirical formula for menthol when a 0.1005g sample of menthol is combusted, producing 0.28298g of CO2 and 0.1159g of H2O. Thank you!
  50. Chemistry

    Hydrocarbon burn in excess oxygen yields 4.4g of carbon(iv)oxide and 2 of 7g of water. Find the empirical formula of hydrocarbon
  51. chemistry

    6.10g of boron reacted completely with 22.9g of chlorine to give 29.0g of the metallic chloride. Calculate the empirical formula of the chloride.
  52. chemistry

    Doing review for an exam and I can't find how to do this problem in my notes. 2 SO2 + 2 Cl2 -----> 2 SOCl2 + O2 from a previous problem I solved: rate=k[SO2]^2[Cl2] k = 467.666666... or in sig. figs 467 Energy reaction: T= 25 C The activation energy
  53. chemistry

    Doing review for an exam and I can't find how to do this problem in my notes. 2 SO2 + 2 Cl2 -----> 2 SOCl2 + O2 from a previous problem I solved: rate=k[SO2]^2[Cl2] k = 467.666666... or in sig. figs 467 Energy reaction: T= 25 C The activation energy
  54. Chemistry due soon

    What is enthalpy? A. Enthalpy is the kinetic energy of a system. B. Enthalpy is the heat involved in a reaction. C. Enthalpy is the temperature of a reaction. D. Enthalpy is the mass involved in a reaction. I think the answer is a or b
  55. chem

    I need major help im not understanding this at all: Complete and balance each of the following equations for acid-base reactions. (Type your answer using the format CO2 for CO2 and Al(OH)3 for Al(OH)3. Use the lowest possible coefficients.) HBr(aq) +
  56. Bio-Chemistry

    Which compound is capable of donating a proton (H+)? A. Acetic acid B. Sodium hydroxide C. Acetylene D. Pentane E. Cyclohexane Which of the following statements is not true of a C-C triple bond? A. Longer bond length than a C=C double bond. B. 180 degree
  57. chemistry

    in a compound of nitrogen and oxygen, 14.0 grams of nitrogen combines with 32.0 grams of oxygen. How much oxygen is required to combine with a sample of 10.5 grams of nitrogen in producing same compound? How do you do the math?
  58. College Algebra

    I have a few more questions that I'm not understanding. Its multiple choice however I would appreciate a breakdown on how to solve. 4.Simplify the compound rational expression. Use either method. 1+(5/y-10)/y+(25/y-10) a. 1/y-5 b. 1/y+5 c. 6/y+25 d.
  59. AP Chem

    A 1.73 g sample of a molecular compound is dissolved in 105 g of tetrachloromethane (carbon tetrachloride). The normal boiling point of the solution is 61.51C, the normal boiling point of CCl4 is 61.2C. The boiling point constant for CCl4 is 4.95 K ·
  60. factoring

    Factor x3 + 9x2 + 27x + 27 Factor 8a3 + 60a2b + 150 ab2+ 125b3 I tried doing them, but I just don't get how; perfect squares didn't work and neither did decomposition... someone please help me.
  61. Logic

    Using truth tree decomposition, determine the consistency of the set of propositions. Include line numbers and justifications, and recover the truth values if consistent. {A and B, ~B v C}
  62. maths

    how to work out partial fraction decomposition when given 1/x(x^2+1) and 2x-1/(x+4)(x-3) if you could give me an idea of the formula and what changes i need to make to the formula when the denominator changes that would help and please use idiot speak
  63. Chemistry

    Use the equation to determine what volume of nitrous oxide can be produced from the decomposition of o.55 moles of ammonium nitrate useing the equation: NH4NO3 (s)--> N2O (g) + 2H2O (g)
  64. math

    Let A= [7 -4 4] [-4 5 0] [4 0 9] a) Orthogonally diagonalize A b) Use answer from a) to construct a spectral decomposition for A. c) Suppose that x=[1 2 1] and let u be the eigen vector from a) corresponding to the largest eigen-value of A. If W=Span {u},
  65. Chemistry Need help ASAP

    A proposed mechanism for a reaction is: (i) A + B2 = AB2 Ea1 = 12 kJ/mol ƒ´H1 = 3 kJ/mol (ii) AB2 + C2 = ABC + BC Ea2 = 30 kJ/mol ƒ´H2 = 5.2 kJ/mol (iii) ABC + B2 = AB2 + BC Ea3 = 10 kJ/mol ƒ´H3 = -7.8 kJ/mol a) Which is the rate determining step?
  66. Chemistry Need help ASAP

    A proposed mechanism for a reaction is: (i) A + B2 = AB2 Ea1 = 12 kJ/mol ƒ´H1 = 3 kJ/mol (ii) AB2 + C2 = ABC + BC Ea2 = 30 kJ/mol ƒ´H2 = 5.2 kJ/mol (iii) ABC + B2 = AB2 + BC Ea3 = 10 kJ/mol ƒ´H3 = -7.8 kJ/mol a) Which is the rate determining step?
  67. Science

    An investigation was conducted to study the effect of the concentration of a reactant on the (trial) time need to complete a chemical reaction. Four trials of the same reaction were performed.In each trial the initial concertration of the reactant was
  68. Chemistry

    2A + 3B + C ⟶ D + E The rate constant for this reaction is 0.25, and the reaction is second order in A and is first order in B and C. Which option correctly gives the rate of the reaction if [A] is 0.4 M, [B] is 0.1 M and [C] is 0.2 M?
  69. PHYSICS

    the consumption of natural gas by a company satisfies the empirical equation V= 1.5t + 0.008t^2 where V is in volume in millions of cubic feet and t is the time in months. what are the dimensions of the constants 1.5 and 0.008?
  70. chemistry

    A non-metal element which lies in the third row of the Periodic Table forms a gaseous compound H2Y with hydrogen and the compound Li2Y with lithium, which has a solid crystalline structure and a high melting point (greater than 900 °C). • A non-metal
  71. chemistry

    write the equations for the substitution reaction of methene with bromine under the following conditions. a) reaction in the presence of sunlight CH4+Br2 sunlight=? b) reaction in the absence of sunlight CH4+Br2 =?
  72. chemistry

    Equilibrium is established in a reversible reaction when: A)the [product] = [reactants] B)rate of reaction of products = rate of reaction of reactants C)all the reactants dissolve or dissociate D)products are no longer produced
  73. Chemistry/Equilibrium calculations

    At 1200 K, the approximate temperature of vehicle exhaust gases, Kp for the reaction 2CO2(g)-> <- 2CO(g)+ O2(g) is about 1 E-13. Assuming that the exhaust gas (total pressure 1 bar) contains 0.2% CO, 12% CO2 and 3% O2 by volume, is the system at
  74. Chemistry

    Tungsten metal can be produced by the reaction of tungsten oxide powder (WO3) with hydrogen gas (H2) in a reactor heated to 800oC. The by-product of the reaction is water vapor (H2O). The reactor is charged with 128.0 kg of WO3 and 41.0 kg of H2. Assume
  75. Chemistry

    Could someone explain Le Chatelier's principle to me? Thanks Reactions tend to go to the direction that reduces stress: stress from pressure, temperature. If a reaction gives off heat (exothermic), it will go faster if temperature is reduced, ie, it is
  76. Chemistry

    for the redox reaction given in the chemical equation Pb(OH)4^2- (aq) + ClO- (aq) --> PbO2 (s) + Cl- (aq) For the oxidation half reaction I got Pb(OH)4^2- (aq) --> PbO2 (s) + 2H2O (l) + 2e- For the reduction half reaction I got 2e- + 2H2O(l) +
  77. Chemistry 101

    Write the reaction that occurs when sodium phosphate and barium chloride react. Be sure to include the phase labels. Then write the total ionic reaction and the net ionic reaction including proper phase labels.
  78. Chem 1200

    Freezing-point depression can be used to determine the molecular mass of a compound. Suppose that 1.28 g of an unknown molecule were added to 19.9 g of water and the freezing point of the solution determined. If the new freezing point of water were found
  79. Chemistry 1200

    Freezing-point depression can be used to determine the molecular mass of a compound. Suppose that 1.28 g of an unknown molecule were added to 19.9 g of water and the freezing point of the solution determined. If the new freezing point of water were found
  80. English (Please help!)

    Which rules are correct for punctuating poems? Select all that apply. A. Use hyphens in compound words or between double adjectives that modify a noun. B. Use dashes in compound words or between double adjectives that modify a noun. C. Use commas to
  81. Chemistry

    In the following reaction, first find how many oxygen molecules would be used to completely react with 230 grams of pentyl alcohol (C5H11OH)? Then, if exactly 1.505x10^21 carbon dioxide molecules were formed in this reaction, calculate the grams of water
  82. Chemistry

    In the following reaction, first find how many oxygen molecules would be used to completely react with 230 grams of pentyl alcohol (C5H11OH)? Then, if exactly 1.505x10^21 carbon dioxide molecules were formed in this reaction, calculate the grams of water
  83. Chemistry

    Reaction: C6H11OH(l) ==> C6H10(l) + H2O(l) Calculate the mass of cyclohexanol (C6H11OH) needed to produce 45.0g cyclohexene (C6H10) by reaction if the reaction has a 86.2% yield and the cyclohexanol is 92.3% pure. Usually this problem would be fairly
  84. Chemistry

    In the following reaction, first find how many oxygen molecules would be used to completely react with 230 grams of pentyl alcohol (C5H11OH)? Then, if exactly 1.505x10^21 carbon dioxide molecules were formed in this reaction, calculate the grams of water
  85. chemistry

    2.241g sample of nickel reacts w oxygen to form 2.85g of the metal oxide. Calculate the empirical formula of the oxide?
  86. chemistry

    combustion analysis of a hydrocarbon produced: 33.01 g CO2 and 13.51 g H2O Calculate the empirical formula of the Hydrocarbon. I got CH5 but that doesn't seem right? how do i do this problem?
  87. Chemistry

    Hi, this is a reply to the question I asked earlier. I asked about the classification and functional group of an organic compound. It has bonds between H-C-C-H. Off of each Carbon is single bonds of Hydrogen above and below. making a total of 6 Hydrogens
  88. Chemistry

    I need definitions for chemistry and I can't come up with any heterogeneous reaction homogeneous reaction activation energy activation energy activated complex elementary reaction
  89. chemistry

    problem 3. A compound Y containing carbon,hydrogen and oxygen was burned in a stream of oxygen,the carbondioxide and water were cooled in a pre way absorption tube and carefully reweighed.Readings obtained were initial mass of Y is 20.63mg mass of
  90. chemistry

    Why are half-reactions used in redox reactions? A. They make it easier to keep track of spectator ions in the reaction. B. They make it easier to see the oxidation and reduction parts of the reaction separately. C. They make it possible to neglect the
  91. chemistry

    "Following the reaction of zinc with hydrochloric acid, a secondary reaction can occur if a product of the first reaction is ignited. Write the complete reactions for both reactions." "If 2.75g zinc with 0.15 moles HCL, how much flammable product can be
  92. Chemistry

    I know nothing about chemistry, but am wondering if someone could help me with these. 1) Balance this redox reaction using the oxidation-number method. Zn + O2 + HCl ® ZnCl2 + H2O 2) Balance this redox reaction using the half-reaction method. (basic
  93. Chemistry

    Consider the following reaction between sulfur trioxide and water: SO3(g)+H2O(l)→H2SO4(aq) A chemist allows 61.5 g of SO3 and 11.2 g of H2O to react. When the reaction is finished, the chemist collects 51.0 g of H2SO4. Determine the percent yield for
  94. Chemistry

    For the following redox reaction, give the complete reduction half reaction. Na(s) + Al+3(aq) Na+1(aq) + Al(s) Please help asap!!
  95. biochemistry

    I am studying for a midterm. Do you know this answer? what reaction does LDH actually catalize and why is that reaction important?
  96. Chem II

    A first-order reaction is 35.5% complete in 4.90 minutes. The rate constant of the reaction is _____
  97. college

    For the reaction P4(s) + O2(g) = P4 O10(s) Identify the limiting reaction mixture conataining 1.00 mol each of P4 and O2
  98. chemistry

    WHAT WOULD HAPPEN TO THE REACTION THAT PRODUCES AMMONIA IF WATER IS PRESENT IN THE REACTION MIXTURE?
  99. Chemistry

    Assume the reaction of 55.25 g of Ge in the following reaction to determine the other quantities. 3Ge + 2N2 -> 1Ge3N4
  100. Chemistry

    Explain, in terms of collision theory, how and why a reaction’s rate changes as the reaction progresses.