1. science

    The primary source of energy in our solar sysem is from? a) fusion reaction on the sun b) fission reaction on the sun c) fission reaction on the earth d) fission and fusion in the galaxy e) fusion reactions in comets the answer i picked was a
  2. Physics

    If a supersaturated sugar solution is allowed to evaporate slowly, sugar crystals form in the container. Hence, sugar molecules go from a disordered form (in solution) to a highly ordered, crystalline form. Does this process violate the second law of
  3. Chemistry

    1. A combination reaction may also be a displacement reaction. True or False 2. The combustion of an element is always a combination reaction. True or False For number 1, I first thought true, but then again, nothing is being displaced in a combination
  4. Chemistry

    An structural isomer of bromobutane (C4H9Br) can be hydrolysed using aqueous sodium hydroxide to produce butanol. This can be represented by the following equation: C4H9Br(l) + OH-(aq)  C4H9OH(l) + Br-(aq) This reaction was investigated
  5. MATH

    Fraction form 1/3 if changed Decimal form it is 1/3=0.331/3 if changed to Percent form it is 1/3=331/3% Is this correct? I just want make sure.
  6. tax

    The educator's expense deduction is taken: A. on Form 2106. B. on Schedule C. C. above the line on the Form 1040. D. on the educator's expense form. it it C
  7. Chemistry

    Which of the following is an example of a double-displacement reaction? AlCl3 + 3 NaOH → Al(OH)3 + 3 NaCl Na2O + H2O → 2 NaOH CuCO3 → CuO + CO2 None of the above are examples of double-displacement. A Which of the following is a
  8. Chemistry

    Write rate law expressions? 2NOCl(g) --> 2NO(g) + Cl2(g) S2O3^2-(aq) + H^+(aq) --> HSO3^-(aq) + S(s) (Sulfur initially forms a colloid solution so it can be treated as aqueous.) (1) Write the rate law expression for the above reactions, assuming
  9. chemistry

    When the reaction is run in a buffer solution, however, it is pseudo-first-order in CH3I. rate = k[CH3] What is the half-life of this reaction in a pH 10.00 buffer if the pseudo-first-order rate constant for this reaction is 7.3 x10-9 s-1?
  10. Chemistry

    Cyclobutane consisting of molecules in which four carbon atoms form a ring decomposes when heated to give ethylene. The reaction is first order. In an experiment, the initial concentration of cuclobutane was 0.00150M. After heating at 450 degrees C for
  11. Chemistry

    Cyclobutane consisting of molecules in which four carbon atoms form a ring decomposes when heated to give ethylene. The reaction is first order. In an experiment, the initial concentration of cuclobutane was 0.00150M. After heating at 450 degrees C for
  12. chem please help

    What is Gibbs free energy? A. The energy lost as heat to the surrounding molecules B. The usable energy released or absorbed by a reaction C. The energy in the form of kinetic energy in a system D. The energy contained within the bonds of molecules Do not
  13. chemistry

    For the electrolysis of molten potassium bromide: (a) write the equation for the reaction at cathode. (b) write the equation for the reaction at anode. (c) write the equation for the overall reaction.
  14. Chemistry(Please help explain)

    The decomposition of hydrogen peroxide in the presence of potassium iodide is believed to occur by the following mechanism: step 1 slow: H2O2 + I^- = H2O + OI^- step 2 fast: H2O2 + OI^- = H2O + O2 + I^- 1) What is the equation for the overall reaction? Use
  15. Chemistry(Can someone please answer!!)

    The decomposition of hydrogen peroxide in the presence of potassium iodide is believed to occur by the following mechanism: step 1 slow: H2O2 + I^- = H2O + OI^- step 2 fast: H2O2 + OI^- = H2O + O2 + I^- 1) What is the equation for the overall reaction? Use
  16. Chemistry

    When the oxide of generic metal M is heated at 25.0 °C, only a negligible amount of M is produced. O2M(s) ----> M(s) +O2(g) Delta G^o = 290.3 kJ/mol When this reaction is coupled to the conversion of graphite to carbon dioxide, it becomes spontaneous.
  17. chemistry

    Hydrogen gas (a potential future fuel) can be formed by the reaction of methane with water according to the following equation: CH4(g)+H2O(g) = CO(g) + 3H2(g) In a particular reaction, 26.5 L of methane gas (measured at a pressure of 736 torr and a
  18. Chemistry

    "How many grams of the precipitate will form if 25.5 mL of 4.5 M solution of lead (II) nitrate is allowed to react with 35.5 mL of 3.0 M solution of potassium chloride? What is the concentration of the excess reactant after the reaction has reached
  19. Chemistry

    Write a balanced equation for the following reaction. Use whole number coefficients and subscripts as appropriate. Carbon tetrachloride is an industrial liquid solvent. It is made by combining methane gas with elemental chlorine. These react to form carbon
  20. Chemistry

    How many grams of glycine amide (FM 74.08) should be used with 1.0 gram of glycine amide HCl (FM 110.54, pKa=8.20) to give 100 mL at pH 8.0? The buffer equilibrium reaction is: GlycineAmideHCl <--- ---> GlycineAmide + H+ which has the general form:
  21. chemistry

    In a reaction vessel, the following reaction was carried out using 0.250 mol of NH3 and 0.100 mol of N2, 4NH3(l) + N2 (g) = 3N2H4 (l) what is the compositon in moles in the vessel when the reaction is completed? Is the answer: 0 mol NH3, 0.063 mol N2, and
  22. chemistry

    20 mL of 0.125 M potassium iodide solution is mixed with 10 mL of 0.1 g L–1 sodium thiosulfate solution and 0.2 g of solid iodine indicator is added. To this solution is added 20 mL of 0.025 M peroxodisulfate solution. After 46 seconds a blue colour
  23. Chemistry

    Barium carbonate and nitric acid reacts in a double displacement reaction. One of products also dissociates and evolves carbon dioxide. Write the net ionic reaction including the proper use of phase labels for this solution run in aqueous solution. After
  24. Chemistry

    For the reaction: 5A + 3B -> 6C + D, the following data is found: Time________A 0.00s .775 M 5.00s .200 M Find the rate of disappearance of A, the overall rate of reaction, and the reates of disapperance and appearance of B, C, and D. The answers I got
  25. chemistry

    Explain why the rate of a simple chemical reaction such as NO(g)+1/2O2(g)=NO2(g) is likey to be most rapid at the beginning of the reaction.
  26. Chemistry

    Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc.
  27. Chemistry

    Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc.
  28. chemistry

    True or False? An equilibrium constant K_c=1x10^7 for a reaction indicates that the reaction favors product formation.
  29. physical science

    the influence of the magnitude of the surface area on the rate of reaction of a specific reaction using rennies tables
  30. Chemistry

    A certain reaction has an activation energy of 58.80 kJ/mol. At what Kelvin temperature will the reaction proceed 6.50 times faster than it did at 303 K?
  31. chemistry

    A certain reaction has an activation energy of 74.38 kJ/mol. At what Kelvin temperature will the reaction proceed 7.00 times faster than it did at 313 K?
  32. chemistry

    A certain reaction has an activation energy of 74.38 kJ/mol. At what Kelvin temperature will the reaction proceed 7.00 times faster than it did at 313 K?
  33. CHEMISTRY

    We have this reaction : HCO3- + OH- => CO3^-2 + H2O Specify the conjugate pairs and , which direction the reaction equilibrium shift ? and How ( as a rule ) ?
  34. Chemistry

    A reaction yields 3.75 L of nitrogen monoxide. The Volume is measured at 19 *C and a pressure of 1.10 atm. What mass of NO was produced by the reaction?
  35. Chemistry

    Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc.
  36. chemistry

    Which term has the same numerical value for the forward reaction as it has for the reverse reaction, but with opposite sign? a. ^E ( delta E) b. Ea1 c. Ea’ d. Ea2
  37. chemistry

    Al2O3+6HCl----->AlCl3+3H2O what type of reaction is this? -combination -decompisition -or double displacement reaction
  38. chemistry

    A certain reaction has an activation energy of 27.34 kJ/mol. At what Kelvin temperature will the reaction proceed 3.50 times faster than it did at 335 K?
  39. chemistry

    2 HI(g) H2(g) + I2(g) The reaction above has an initial concentration of 2.00 M HI. (No other species are initially present.) If 22.4% of the HI has reacted when equilibrium is established, calculate Kc for the reaction.
  40. Science!

    1) Which of the following is true about photosynthesis? A. it is an exothermic reaction B. it is an endothermic reaction C. It produces carbon dioxide D. it occurs in animals I think it's A.
  41. Chemistry

    A certain reaction has an activation energy of 25.65 kJ/mol. At what Kelvin temperature will the reaction proceed 5.50 times faster than it did at 291 K?
  42. Science

    If the concentration of AgCl drops from 1.000 M to 0.655 M in the first 30.0 s of the reaction, what is the average rate of reaction over this time interval?
  43. chemistry

    The reactant concentration in a second-order reaction was 0.790 after 200 and 8.80×10−2 after 740 . What is the rate constant for this reaction?
  44. Chemistry

    Predict the products and write a net ionic reaction for the reaction of cadmium chloride and ammonium sulfide.
  45. chemistry

    If the reaction Cl2 (g) + O3 (g) = Cl2O (g) + O2 (g) occurred in just two steps, what would be the overall order of the reaction be? a. 1 b. 2 c. 3 d. 4 e. not possible to determine from the information given i have absolutly no idea how to do this
  46. Chemistry

    For the reaction HCONH2(g) --> <--NH3(g) + CO(g), Kc = 4.84 at 400 K. If delta H for this reaction is 29 kJ/mol, find Kc at 500 K. The answer is 27 I just don't know why.
  47. chemistry

    The reaction x products follows Ist order kinetics in 40 minutes the concetration of x changes from 0.1M to 0.025M then the rate of reaction when conc of x is 0.01
  48. Chem

    A certain reaction has an activation energy of 66.58 kJ/mol. At what Kelvin temperature will the reaction proceed 4.50 times faster than it did at 289 K?
  49. Chemistry

    the reaction of 6.62g of carbon with excess oxygen yields 13.40g of CO2. what is the percent yield of this reaction
  50. Kinetics Problem II

    The data below were collected for the following reaction: 2NO2 (g) + F2 (g) ->2NO2F(g) A: Calculate the value of the rate constant, k. B: What is the overall order of the reaction?
  51. Chemistry

    A gas-phase reaction has Kp = 2.44 × 10 20 at 25 ◦ C. Calculate ∆G 0 for this reaction. Answer in units of kJ/mol rxn
  52. Chemistry

    Explain the reaction mechanism of the following reaction by showing the types of bond splitting and atom rearrangements. C + O2 = CO2
  53. chem.

    A certain reaction has an activation energy of 66.58 kJ/mol. At what Kelvin temperature will the reaction proceed 4.50 times faster than it did at 289 K
  54. Chemistry - Rates

    For a particular reaction, the rate constant is 2.32 ✕ 10−3 M/s at 185°C and 3.70 ✕ 10−3 M/s at 235°C. What is the activation energy for this reaction? _______ kJ/mol
  55. chemistry

    How many liters of HCl are produced by the reaction of 5.7 L of hydrogen with an equal amount of chlorine? The reaction occurs at STP.
  56. chemistry

    Explain the reaction mechanism of the following reaction by showing the types of bond splitting and atom rearrangements. C + O2 = CO2
  57. Chemistry

    in a particular redox reaction, Cr is oxidized to CrO42- and Ag+ is reduced to Ag. Complete and balance the equation for this reaction in acidic solution.
  58. Chemistry

    for a particular reaction H=-28.4 KJ and S=-87.9 J/K. Assuming these values change very little with temperture, over what temperature range is the reaction spontaneous in the forward direction?
  59. Chemistry

    For the balanced redox reaction 2 Al(s) + 3 Br2(g) → Al2Br6(s), determine the number of electrons transferred in the overall reaction.
  60. chemistry

    A certain reaction has an activation energy of 25.14 kJ/mol. At what Kelvin temperature will the reaction proceed 8.00 times faster than it did at 305 K?
  61. chemistry

    Question: When a pink aqueous solution of potassium permanganate, faintly acidified with dilute sulfuric acid was treated with 10% aq. hydrogen peroxide, the reaction took place with the evolution of gas bubbles, and the pink solution was turned colorless.
  62. precalc

    Suppose that z1=6-8i. Find: A. The Trig Form of the complex number z1, where your theta is in degrees. B. The Trig form of z1*z2, where z2=5[cos(60degrees)+isin(60degrees)] C. The Trig Form of (z1)^4
  63. Science (chemistry)

    Write a balanced chemical equation and state the reaction type for each of the following reactions: a.) nitrogen gas reacts with hydrogen gas forming ammonia (NH3) b.) carbonic acid breaks down to form carbon dioxide gas and water c.) aluminum foil reacts
  64. Chemistry

    2 H2S (g) + SO2 (g) <===> ƒnƒn3 S (s) + 2 H2O (g) 1) At 298 K, the standard enthalpy change, H¢X, for the reaction represented below is -145 kilojoules. (a) Predict the sign of the standard entropy change, S¢X, for the reaction. Explain the basis
  65. Chemistry; Stoichiometry

    Consider the reaction 2Al + 3CuSO4 = Al2(SO4)3 + 3Cu What is the maximum amount of Cu (63.5 g/mol) that could be produced by reacting 20.0 grams of Al (27.0 g/mol) with excess CuSO4? 1. 70.6 g 2. 57.2 g 3. 129 g 4. 31.4 g Consider the reaction 4As + 3O2 =
  66. Chem Help Please!

    Compare the relative reaction rates of 1-bromobutane, 2-bromopropane, and 2-bromomethylpropane under SN1 reaction conditions. Silver nitrate will be used to provide nitrate ion as the nucleophile to produce alkyl nitrates as products. 1) I found the answer
  67. Algebra

    What is 2x=7? Is it a standard form, or slope-intercept form, or not a linear equation? Can you explain what a standard form and a slope-intercept form is PLEASE!? The standard form for a straight line is y=mx+b where m is the slope and b is the y
  68. AP Chem (Conceptual Questions)

    Hey guys! If you could just please, look over a few of these conceptual problems because I'm pretty confused? (I put what I think is the answer below each question). Thank you for any help in advance!!!! A.Which statement *does not* apply to a
  69. Chemistry

    When 442 mg of NO2 is confined to a 150. mL reaction vessel and heated to 300°C, it decomposes by a second-order process. In the rate law for the decomposition of NO2, k = 0.54 1/(M·s). A) what is the initial reaction rate? B) what is the reaction rate
  70. organic chem

    Please help! It's one of the prelab questions. **Exp. Ethanol from Sucrose The diethylacetal of acetaldehyde can be detected by gas chromatography. How does this impurity arise in fermentation? **Exp. Acetaminophen In the reaction between p-aminophenol and
  71. Chemistry

    True or False: A non-spontaneous reaction is converted into a spontaneous reaction in a voltaic cell by the expense of electrical energy. I believe it is true because in a non spontaneous reaction, energy must be induced in order for it to occur. Is this
  72. Chemistry

    What is the difference between a forward and a reverse reaction? I am studying Lechatelier's principal and it states that with an increase in temperature it favors a reverse reaction and when the temperature decreases it favors a forward reaction. What
  73. Chemistry

    At a given temperature, a first-order reaction has a rate constant of 3.5 ´ 10–3 s–1. How long will it take for the reaction to be 24% complete? A chemical reaction that is first-order in X is observed to have a rate constant of 2.20 ´ 10–2 s–1.
  74. chemistry

    Consider the first order reaction A --> products where 25% of A disappears in 24 seconds. What is the half life of this reaction? ...i thought it would just be doubled but it isn't. i'd appreciate an explanation.
  75. Chemistry

    For the reaction given below, the frequency factor A is 8.7 multiplied by 1012 s-1 and the activation energy is 63 kJ/mol. NO(g) + O3(g) NO2(g) + O2(g) What is the rate constant for the reaction at 55°C?
  76. Chemistry

    For the reaction given below, the frequency factor A is 8.7 multiplied by 1012 s-1 and the activation energy is 63 kJ/mol. NO(g) + O3(g) NO2(g) + O2(g) What is the rate constant for the reaction at 55°C?
  77. why will no one answer? chem

    If the reaction Cl2 (g) + O3 (g) = Cl2O (g) + O2 (g) occurred in just two steps, what would be the overall order of the reaction be? a. 1 b. 2 c. 3 d. 4 e. not possible to determine from the information given i have absolutly no idea how to do this
  78. college

    For the reaction NO(g) + O3(g) „_ NO2(g) + O2(g) The frequency factor A is 8.7 X 1012 s-1 and the activation energy is 63kJ/mol. What is the rate constant for the reaction at 75 ¢XC?
  79. Science Help!

    Which of the following is true about photosythesis? A. It is an exothermic reaction B. It is an endothermic reaction C. It produces carbon dioxide D. It occurs in animals Is the answer C? Thank you
  80. sofunda

    science chemistry..investigate the reaction of a number of elements and compound with water and classify the reaction as exothermic or endothermic.
  81. Chemistry

    The rate constant of a particular reaction is halved when the temperature is decreased from 323 K to 273 K. Calculate the activation energy for the reaction.
  82. Chemistry

    A particular reaction has an activation energy of 51.6kJ/mol-rxn. How much faster is the reaction at 50 degrees C versus 25degrees C? I do not know how to start this!
  83. Chemistry

    Examine the redox reaction. As2O3(s) + Cl2(g) + H2O(l) → H3AsO4(aq) + HCl(aq) How many electrons are lost by each As atom during the reaction? A)4 B)3 C)2 D)1
  84. chemistry

    Represent this reaction with a balance chemical equation. Solid aluminium hydride is formed by a combination reaction of its two elements.
  85. chemistry

    For the following reaction in acidic solution. Cr2O7^2- + I- ---> Cr^3+ + IO3- give the balanced half reduction reaction. Indicate the oxidizing species.
  86. Chemistry

    How many grams of fluorine are needed to produce 120. g of phosphorus trifluoride if the reaction has a 78.1% yield from the following reaction: P4+6F2 -> 4PF3
  87. Chemistry

    When acetone, C3H6O, is oxidized via combustion, the following reaction can be envisioned. Balance this reaction and determine the total of the coefficients when added together.
  88. Chemistry

    In a few concise sentences, explain how you could predict the products of a chemical reaction using the reaction between sodium nitrate and magnesium phosphate as an example?
  89. Chemistry

    In a few concise sentences, explain how you could predict the products of a chemical reaction using the reaction between sodium nitrate and magnesium phosphate as an example?
  90. Chemistry

    Given the reaction below, and your knowledge of the "Law of Conservation of Mass", what is the missing product from the chemical reaction? How do you know? Zn(s) + HCl(aq) --> ___ + ZnCl2(aq)
  91. Chemistry

    Consider the reaction when aqueous solutions of manganese(II) sulfate and barium bromide are combined. The net ionic equation for this reaction is:???
  92. chemistry

    For the reaction A to products}, the following data were obtained: t=0 s, A}]=0.715 M; 22 s, 0.605 M; 74 s, 0.345 M; 132 s, 0.055 M. What is the half-life of the reaction?
  93. chemistry

    For the reaction A to products}, the following data were obtained: t=0 s, A}]=0.715 M; 22 s, 0.605 M; 74 s, 0.345 M; 132 s, 0.055 M. What is the half-life of the reaction?
  94. Chemistry - Science (Dr. Bob222)

    Consider reaction below: 50H3O^+(aq) + 7Cr2O7^2-(aq) +3I_2(aq) --> 6IO_4^-(aq) + 14Cr^3+(aq) + 75H2O (l) How many electrons are transferred in this reaction?
  95. chemistry

    Consider the following reaction: 2 Mg + O2 → 2 MgO △H rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg.
  96. Chemistry

    A first-order reaction has a half-life of 26.4 seconds. How long does it take for the concentration of the reactant in the reaction to fall to one-eighth of its initial value?
  97. chemistry... please help!

    A mass of 11.6g of phosphoric acid was produced from the reaction of 10g of P4O10 with 12g of water. What was the percent yield for this reaction?
  98. chemistry

    For the reaction A to products}, the following data were obtained: t=0 s, A}]=0.715 M; 22 s, 0.605 M; 74 s, 0.345 M; 132 s, 0.055 M. What is the half-life of the reaction?
  99. gr10 science

    The products of the reaction are iron (III) hydroxide and sodium chloride. How could I write a word equation for this reaction?
  100. (19) Chemistry - Science (Dr. Bob222)

    Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E° = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E° = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be