1. Chemistry

    A reaction has a standard free-energy change of –12.40 kJ mol–1 (–2.964 kcal mol–1). Calculate the equilibrium constant for the reaction at 25 °C.
  2. College Chemistry

    The maximum amount of product D that can be produced from the following reaction is 55.75 g. 2A + B ¨ 2C + 3D Following an experiment based on this reaction, when the D was isolated, 50.67 g of D were obtained. What is the percent yield for this
  3. chemistry

    3PbO2 + 2Cr3++ 2H2O3Pb2+ + 2CrO42-+ 4H+ 1. In the above reaction, the oxidation state of chromium changes from (answer) to (answer). 2. How many electrons are transferred in the reaction?
  4. science

    write an equation relating the concentration of a reactant A at t=0 to that of t=t for a first order reaction. Define all the terms and give their units. Do the same for a second order reaction.
  5. chem

    If it takes 84.2 min for the concentration of a reactant to drop to 20.0% of its initial value in a first-order reaction, what is the rate constant for the reaction in the units min-1?
  6. chemistry

    What mass of copper(II) nitrate would be produced from the complete reaction of 25.1 g of copper, according to the chemical reaction shown below? Cu + 2 AgNO3 ----> Cu(NO3)2 + 2 Ag i got 74.08 is that correct?
  7. Biology

    What will happen to the enzyme activity if both competetive and non-competetive inhibitors appear at the same time together with substrates in a reaction? Which inhibitor will affect the rate of the reaction in more?
  8. Chemistry

    A reaction: A(aq) + B(aq) C(aq) has a standard free-energy change of –4.65 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M, respectively?
  9. Biology

    What will happen to the enzyme activity if both competetive and non-competetive inhibitors appear at the same time together with substrates in a reaction? Which inhibitor will affect the rate of the reaction in more?
  10. Chemistry

    Suppose we had mixed 52.37 mL of 1.00 M HI solution with 25.42 mL of 1.00 M KOH solution, and measured a heat of reaction of -1.52 kJ. What is ΔH for this reaction, in kJ? Assume that all solutions have the same density as water (1.00 g/mL).
  11. Chemistry

    A reaction has a standard free-energy change of –12.40 kJ mol–1 (–2.964 kcal mol–1). Calculate the equilibrium constant for the reaction at 25 °C.
  12. Chemistry

    Suppose 1 gram of Li2CO3 is reacted with in 50.0 mL of 3.00 M HCl. What would be the mass of CO2 liberated in the reaction? After the reaction, how many moles of HCl are left over?
  13. Chemistry

    A reaction A+B---> C has a standard free energy change of -5.13 kj/mol at 25 degrees celcius, What are the concentrations of A, B, and C at equilibrium if at the beginning of the reaction there concentrations are .3M, .4M, and 0M respectively?
  14. AP CHEMISTRY!!!!

    Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2 CO(g) + O2(g) → 2 CO2(g) ∆H for this reaction is −566 kJ/mol rxn. What is the ∆H for CO(g)?
  15. Chem

    Which direction will the following reaction in a 5.0 L flask proceed if Qp = 0.013? 2H2O(g) = 2H2(g) + O2(g) Kp = 1.6 x 10-5 Choose one answer. a. to the right because Q > Kp b. to the left because Q > Kp c. to the right because Q < Kp d. to the left
  16. Chemical kinetics

    The energy of activation for a reaction is 100kj/mol.Presence of catalyst lowers the activation by 75%.What will be the effect on rate of reaction at 20°C, other things being the same.
  17. Chemistry

    The reaction X + Y --> Z the reaction rate is for to depend only upon the concentration of X. A plot of 1/X versus time gives a straight line. What is the rate law for this reation?
  18. CHEM

    A gaseous hydrocarbon (an organic compound consisting of C & H) weighing 0.232g occupies a volume of 102mL at 23 degrees Celcius and 749mmHg. Calculate the molar mass and identify the compound. The compound is: a)C2H4 b)C3H6 c)C4H8 d)C5H10 e)C6H12 How is
  19. CHEMISTRY PLEASE!!! ( I NEED HELP ASAP)

    Consider the reaction H3PO4 + 3NaOH → Na3PO4 + 3H2O. How much Na3PO4 can be prepared by the reaction of 3.43 g of H3PO4 with an excess of NaOH? For the reaction ?Fe+?H2O → ?Fe3O4 +?H2, what is the maximum amount of Fe3O4(231.533 g/mol) which could be
  20. English

    Write ten sentences about different people places or things. Begin each sentence with a compound subject. Make sure the compound subject and the verb agree. 1.My friend and I go to the park on the weekend. 2.Lance and Darren don't want to go to the party.
  21. chemistry

    Equilibrium constant K for some reaction at temperature 300K was found to be 100 .Calculate equilibrium for same reaction at 400K if R= 8.23 change in enthalpy is 5000J
  22. chemistry

    which of the following is a characteristic of a catalyst? a...can convert an endothermic to an exothermic reaction b...raises the EA c...raises the energy of the reactant(s) d...is recovered unchanged after completion of the reaction
  23. science

    when a zinc is placed in a copper(ii)nitrate solution,the strip becomes coated with copper.write down the oxidation half reaction for the reaction that takes place.
  24. Chemistry

    Write the balanced chemical reaction (showing appropriate symbols and states) for the chemical reaction with enthalpy change equal to ΔHf° [NH3(g)]
  25. chem

    Reaction H2 +I2 yields 2HI All three gases are initially at 0.1atm/ upon reaching equilibrium it is found that H2 pressure droped by 55% what is the equilibrium constant for this reaction.
  26. chemistry half reactions

    How do i solve this half reaction with Mg(OH)2(s) --> Mg(s)? Complete and balance the displayed half reaction in basic aqueous solution taking into account the electrons. Mg(OH)2(s) → Mg(s)
  27. chemistry

    find mass of magnesium nitride produced in reaction of 5.0of magnesium with 10.0gof nitrogen. the reaction was carried out in a closed container
  28. science(chem)

    NaClO3 + H2O + HCl=> what form is the Cl in ? I know that a gas is formed but the reaction that I did also had Cl reacting with the reactants so I'm not sure in what form of Cl did my reactant react with the product of the above reaction. Thanks
  29. Chemistry

    For the reaction 2NH3(g) 3H2(g) N2(g) at 472oC equilibrium is established when [H2] =0.0200M, [N2] = 0.0100M and [NH3] = 5.37x10^_8 M. What is the equilibrium constant for the reverse reaction?
  30. chem--electrochemistry

    So in this reaction: Ag(s) + Fe(+3) --> Ag(+) + Fe(+2) we are given 20 grams of Ag(s) to start off with. How do we find how many electrons are transfered in the reaction. And how many grams of Fe(+2) is formed. *for the latter, i think that we can
  31. biochemistry

    Reaction A B proceeds with H = 240 kJ×mol-1; S = 40 J×K-1×mol-1. Substance A was taken at initial concentration 2 mM. Determine the concentrations of A and B after the reaction reaches equilibrium at 298 K.
  32. Chemistry

    Consider the rxn during the Haber Process: N2 + 3H2 ---> 2NH3 The equilibrium constant is 3.9 x 10^(5) at 300 K and 1.2 x 10^(-1) at 500 K. Find Delta H reaction and Delta S for reaction
  33. chemistry 101

    given the reaction: 2mg + o2-----> 2mgo . when 4.32g of oxygen react with magnesium 327kj of energy is produced. the heat of reaction for 1 mole of oxygen is???
  34. Science

    A reaction has a standard free-energy change of –11.70 kJ mol–1 (–2.796 kcal mol–1). Calculate the equilibrium constant for the reaction at 25 °C. Im so lost please help
  35. Chemistry

    2NO(g) + H2(g) --> N2O(g) + H2O(g) + energy. 1. Assume the reaction is reversible and at equilibrium. What shifts in the equilibrium of this reaction are suggested by Le Chateliers Principle?
  36. chemistry

    questions 1)why Benzaldehyde and acetone can't do self condensation in claisen-schmidt reaction condensation? 2)In the second step of same reaction why do we add ethanol to form dibenzalideneacetone ?
  37. Chemistry!!!

    Consider the rxn during the Haber Process: N2 + 3H2 ---> 2NH3 The equilibrium constant is 3.9 x 10^(5) at 300 K and 1.2 x 10^(-1) at 500 K. Find Delta H reaction and Delta S for reaction
  38. AP Chemistry

    For the reaction cyclopropane(g) → propene(g) at 500◦C, a plot of ln[cyclopropane] vs t gives a straight line with a slope of −0.00067 s−1 . What is the order of this reaction and what is the rate constant?
  39. Chemistry

    the standard free energy change for a chemical reaction is +13.3 kj/ mol. What is the equilibrium constant for the reaction at 125 degree C ? (R= 8.314 j/mol )
  40. Chemistry

    A reaction has a standard free-energy change of -11.80 kJ/mol (-2.820 kcal/mol). Calculate the equilibrium constant for the reaction at 25 degrees C. Please help!
  41. Chemistry

    During a reaction, you see that the heat (q) given off is 4.6 cal calories. Knowing that you used a mass of 100 g and that the temperature change was 7.85°C, what is the specific heat of this reaction?
  42. chemistry(check my answer)

    From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured? A. 2H+ + 2e–H2 B. Li+ + e–Li C. O2 + 4H+ + 4e–2H2O D. F2 + 2e–2F– E. H2 +
  43. chemistry

    What mass of copper(II) nitrate would be produced from the complete reaction of 25.1 g of copper, according to the chemical reaction shown below? Cu + 2 AgNO3 ----> Cu(NO3)2 + 2 Ag
  44. biochem

    When making Aspirin, I know that sulfuric acid is used as a catalyst. But i was wondering 1.) if the reaction would happen without the cataylst and 2.) can other substances be used as a cataylst in this reaction?
  45. Chemistry

    During a reaction, you see that the heat (q) given off is 4.6 cal calories. Knowing that you used a mass of 100 g and that the temperature change was 7.85°C, what is the specific heat of this reaction?
  46. science

    For the reaction mc011-1.jpg at 472°C equilibrium is established when [H2] =0.0200M, [N2] = 0.0100M and [NH3] = 5.37 x 10-8M. What is the equilibrium constant for this reaction
  47. AP Chemistry

    redox reaction: Hydrogen peroxide is added to an acidified solution of potassium permanganate. what is the total redox reaction?
  48. chem

    What mass of copper(II) nitrate would be produced from the complete reaction of 25.1 g of copper, according to the chemical reaction shown below? Cu + 2 AgNO3 ----> Cu(NO3)2 + 2 Ag
  49. Chemistry

    A reaction in which X and Y form products was found to be second order in X and first order in Y. By what factor will the rate of the reaction change if [X] is doubled and [Y] is tripled? a. 10 b. 12 c. 20 d. 2
  50. Gen Chem

    The signs of DG, DH, and DS at 25°C are shown in the table below for three reactions. Reaction DG DH DS I - + + II - - + III - - - Which reaction or reactions should go in the REVERSE direction at high temperature?
  51. chemistry

    Consider the following overall reaction which is experimentally observed to be second order in AB and zero order in C: AB+C -> A+BC Determine whether the mechanism below is valid for this reaction AB+ AB -> AB(sub 2) + A slow AB(sub2) + C -> AB+BC fast
  52. chemistry

    Consider the following overall reaction which is experimentally observed to be second order in AB and zero order in C: AB+C -> A+BC Determine whether the mechanism below is valid for this reaction AB+ AB -> AB(sub 2) + A slow AB(sub2) + C -> AB+BC fast
  53. Chemistry

    Consider the reaction below. 3 O2(g) --> 2 O3(g) At 175°C and a pressure of 128 torr, an equilibrium mixture of O2 and O3 has a density of 0.168 g/L. Calculate the Kp for the above reaction of 175°C
  54. Chemistry

    The balanced reaction equation for the combustion of heptane, C7H16, is given below. If the reaction produced 37.5 g CO2, how many grams of heptane were burned?
  55. chemistry

    For a particular redox reaction NO is oxidized to NO3^– and Cu^2+ is reduced to Cu. Complete and balance the equation for this reaction in basic solution: NO + Cu^2+ --> NO3^- + Cu^+ help. thanks.
  56. chemistry

    What is the enthalpy for reaction 1 reversed? reaction 1 reversed: 2CO2+3H2O=C2H5OH+3O2 express the answer in kJ/mol
  57. Chemistry

    Consider the reaction below. 3 O2(g) --> 2 O3(g) At 175°C and a pressure of 128 torr, an equilibrium mixture of O2 and O3 has a density of 0.168 g/L. Calculate the Kp for the above reaction of 175°C
  58. Chemistry

    From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured? A. 2H+ + 2e– ==> H2 B. O2 + 4H+ + 4e– ==> 2H2O C. F2 + 2e– ==> 2F– D. Li+ + e–
  59. Chemistry

    Consider the generic reaction between reactants A and B: 3A+4B→2C How many moles of B will be in the reaction vessel once the reactants have reacted as much as possible? (Assume 100% actual yield.)
  60. chemistry

    Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:2X2Y⇌X4Y2 (fast)X4Y2+Z2→2X2YZ (slow)
  61. chemistry

    Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:X2Y+Z2→X2YZ2 (slow)X2YZ2→X2YZ+Z (fast)
  62. science

    AgNO3+NaCL=AgCL+NaNO3 is not a redox reaction but Cu+2AgNO3=2Ag+Cu(NO3)2 is a redox reaction.explain
  63. chemistry

    operating conditions 250-300 celcius and 50-100 atmospheres are consistent with the aims of achieving a high equilibrium yield of methanol and a high rate of production. noting any conflicts, explain the role of a copper catalyst noting how its presence
  64. Physical Science

    10. The more compact a metal is, the less brittle it becomes. -True? I'm confused about this one because of what the textbook says: "the more compact the atoms become, the harder the metal becomes. While the compactness makes the metal hard, a fracture on
  65. Physical Science

    10. The more compact a metal is, the less brittle it becomes. -True? I'm confused about this one because of what the textbook says: "the more compact the atoms become, the harder the metal becomes. While the compactness makes the metal hard, a fracture on
  66. science

    sorry to annoy anyone, but WHAT is the big idea of energy? i would really appreiciate a response In what context? Too much use. Not reneewable? Cost? availability? in the context of an ironsulphide reaction I still don't understand the question. explaining
  67. Chemistry

    I have 3 I don't understand how to do. A 33.2 g of iron ore is treated as follows. The iron in the sample is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 12.3 grams. What was the percent iron in the sample
  68. Chemistry

    Hi, I am having trouble determining the correct answer for this question. Which one of the following decay modes has not been observed? A)neutron emission B)Positron emission C)Alpha emission D) electron capture I don't know what does it mean be
  69. Chemistry

    The reaction 2NO (g) + 2H2 -> N2 (g) + 2H2O (g) was found to follow the rate law, rate = k[NO]^2[H2]. By what factor will the rate of reaction increase when the pressure of NO gas is increased from 2.0 atm to 3.0 atm? Assume all other conditions are held
  70. chemistry

    Base your answer on the following redox reaction, which occurs spontaneously in an electrochemical cell. Zn + Cr3+ --> Zn2+ + Cr Write the half-reaction for the reduction that occurs.
  71. Chemistry 143

    Write three thermochemical equation needed to calculate delta H for the following reaction: 2Mg(s) + O2(g) = 2MgO Include delta h values in kJ for each reaction. Please help!! I don't even know were to start!!
  72. Chemistry

    Consider the following chemical reaction 2HCl+Ca(OH) CaCl+2H2O you have a mixed solution with 20.00mL of 0.100M Ca(OH)2 solution What is the molarity of the HCl,Ca(OH)2 and CaCl2 after the reaction has stopped?
  73. chemistry

    For the reaction Al (s) + 3 HCl (aq) -> AlCl3 (s) + ₃/₂ H2 (g), it was observed that when 4.00 g of aluminum reacted with excess HCl, exactly 30.0 kJ of heat were released. The delta H for this reaction is a) – 91.3 kJ b) – 120 kJ c) – 202 kJ d)
  74. 12th grade

    gaseous ammonia is made by the following reaction: N2+3H2 - 2NH3. if you start with 7 liters on nitrogen gas, how many liters of hydrogen are needed for a chemical reaction?
  75. Chemistry

    (a) Calculate the standard free-energy change (ΔG°) for the following oxidation-reduction reaction. Cu(s) + Br2(aq) → Cu2+(aq) + 2 Br−(aq) (b) Calculate the equilibrium constant for this reaction at 298 K.
  76. chemistry

    For the reaction Al (s) + 3 HCl (aq) -> AlCl3 (s) + ₃/₂ H2 (g), it was observed that when 4.00 g of aluminum reacted with excess HCl, exactly 30.0 kJ of heat were released. The delta H for this reaction is a) – 91.3 kJ b) – 120 kJ c) – 202 kJ d)
  77. Chemistry

    2 NO + O2 --> 2 NO2 The reaction rate is increased five­fold when the temperature is  increased from 1400 K to 1500 K. What is the activation energy for the reaction?  I have no idea how to do this and would greatly appreciate some
  78. Chemistry

    Calcium fluoride (CaF2) is a slightly soluble salt, which dissociates in water according to the following reaction: CaF2(s) ⇌ Ca2+(aq) + 2F–(aq) What is the solubility product constant for this reaction?
  79. Chemistry

    Pb(aq)2+ + 2e- → Pb(s) Ero = - 0.13 V Sc(aq)3+ + 3e- → Sc(s) Ero = - 2.02 V a) Write a balanced chemical equation for a spontaneous reaction involving these half reactions. b) Explain your rationale for the reaction going in this direction. I'm not
  80. chem class

    The value of Keq for the following reaction is 0.25: SO2 (g) + NO2 (g) SO3 (g) + NO (g) The value of Keq at the same temperature for the reaction below is __________. 2SO2 (g) + 2NO2 (g) 2SO3 (g) + 2NO (g) answer is 0.25 how do i figure this out?
  81. Chem

    2 H2O (l) → 2 H2 (g) + O2 (g) Using the thermodynamic values to calculate accurate values of ΔHr and ΔSr, will the reaction be product favored at high temperature? Why? r stands for reaction
  82. chemistry

    The following reaction was monitored as a function of time: AB--->A +B A plot of 1/[AB] versus time yields a straight line with slope 5.2 x 10^-2 M*s. What is the value of the rate constant (k) for this reaction at this temperature?
  83. chemistry

    By applying Le Châtelier’s principle to a reaction that has come to equilibrium, the reaction can be made to A. produce more reactants. B. run to completion. C. reach a new chemical equilibrium. D. All of the above Is the answer D?
  84. chem

    Pb(aq)2+ + 2e- → Pb(s) Ero = - 0.13 V Sc(aq)3+ + 3e- → Sc(s) Ero = - 2.02 V a) Write a balanced chemical equation for a spontaneous reaction involving these half reactions. b) Explain your rationale for the reaction going in this direction.
  85. Chemistry

    A reaction : A(aq)+B(aq) --> C(aq) has a standard free-energy change of –4.01 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M,
  86. Biochemistry

    Is there a reaction between Na2SO4 with Ch2Cl2? We did a caffeine extraction from tea bags and we are asked why the Na2So4 was added (to remove water I learned) and if a reaction took place. Can someone help? Thanks!
  87. Chemistry

    In the equation: Fe(NO3)3 (aq) + 3KSCN (aq) forms FeSCN3 (aq) + 3KNO3 (aq) What type of reaction is this? why are there two aqueous solutions as products? Is there a secondary reaction? Finally is there a name for these products?
  88. chemistry

    Under standard conditions for all concentrations, the following reaction is spontaneous at 25 ¢XC with EO = 0.16 V. + - 02 (g) + 4 H (aq) + 4 Br (aq) -+ 2 H20 (I) + 2 Br2 (1) If [H+] is a?justed by adding a buffer of 0.10 M NaOCN and 0.10 M HOCN (Ka = 3.5
  89. physhic

    For every reaction there is an exact opposite reaction. True! The question one could ask and explore is what came first? or who or what the reaction is. Could we agree good is supieror to evil just to make my point your preference, makes no difference. If
  90. chemistry - kinetics

    Understanding the high-temperature behavior of nitrogen oxides is essential for controlling pollution generated in automobile engines. The decomposition of nitric oxide (NO) to N2 and O2 is second order with a rate constant of 0.0796 M−1*s−1 at 737∘C
  91. chemistry

    The correct interpretation of the equation below is:? Fe3+(aq) + SCN¨C(aq)¡ú FeSCN2+(aq) A. The reaction is incomplete because the product is still charged. B. A heterogeneous equilibrium exists because of the charged ions. C. The equilibrium constant
  92. Chemistry

    Use enthalpies of formation from the textbook to calculate the standard enthalpy of the reaction for the following methane- generating reaction of methanogenic bacteria given delta Hf of CH3NH2=-22.97kJ/mol: 4CH2NH2+2H2O----->3CH4+CO2+4NH3
  93. Inorganic chemistry

    The standard free energy change for a chemical reaction is -18.3kJ/mole. What is the equilibrium constant for the reaction at 87 degrees Celsius? (R=8.314J/K*mol) Delta G = -Rtlnk -18,300/8.314/360 = -6.114
  94. chem

    Consider the following unbalanced equation: C2H5OH(g) + O2(g) → CO2(g) + H2O(l) 1.55 g of ethanol reacts with 10.0 g of oxygen. What is the total volume of gas present (in L) after the reaction is complete, assuming the reaction takes place at 1.00 atm
  95. Organic chem

    When you react 1-octene wih borane tetrahydrofuran solution and hydrogen peroxided over NaOH and water... (hydroboration- oxidation reaction) how do you run the reaction differently to improve the yield of the major product 1-octanol?
  96. Chemistry

    Mg + 2HCI --> MgCl2 + H2 0.158 g of Mg metal is combined with an excess of HCl to make 100.0 ml of solution in a coffee up calorimeter. The reaction rises from 25.60 C to 32.80 C. Determine delta H for the reaction of one mole of Mg. Units in kJ. 3
  97. chemistry

    The percentage of C,H,O in vitamin C were determined by burning a sample weighing 2.00g. The masses of carbon dioxide and water formed are 3.00mg and 0.81mg respectively. Find the percentage of each element and the empirical fomula of vitamin C
  98. Chemistry

    A reaction A(aq)+B(aq)C(aq) has a standard free-energy change of –3.35 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M, respectively?
  99. chemistry

    balance the following equation, and identify the type of reaction. ZnSO4+SrCl2-> i think it's a double replacement reaction. But could someone please help me balance it. I'm not sure how.
  100. Chemistry

    making 2 moles of No in a reaction requires 180KJ of energy. How much No will be made if this same reaction absorbel 950KJ OF ENERGY