1. 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.
  2. Chemistry

    When K is measured for a reaction, the values obtained are 3.1 at 25°C and 7.42 at 35°C. Using the equation lnK=-(∆H°/R)(1/T)+(∆S°/R) (in the form y=mx+b) calculate ∆H° and ∆S° for the reaction PbCl2(s) --> Pb2+(aq) + Cl-(aq)
  3. 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?
  4. 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.
  5. 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 ) ?
  6. help please?!

    If it takes 30 seconds for a reactant concentration to decrease from 1.0 M to 0.5 M in a first-order chemical reaction, then what is the rate constant for the reaction?
  7. 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 =?
  8. 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
  9. 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
  10. 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
  11. Chemistry

    Ok, so in an when an endothermic reaction occurs, is it hot or cold? and why? Also what is it for an exothermic reaction? Thank you
  12. Chemistry

    Show that the reaction caco3 ->cao+co2 is not a redox reaction
  13. Chemistry

    Since decomposition is an endergonic reaction. Does this mean it's reverse reaction synthesis is exothermic?
  14. Chem

    Why do the rate of reaction for a reversible reaction slows down at equilibrium stage.
  15. physical science(chemistry)

    Why can chemical methods not be used to determine the reaction rate at different stages of the reaction?
  16. Chemistry

    Ok, so in an when an endothermic reaction occurs, is it hot or cold? and why? Also what is it for an exothermic reaction? Thank you
  17. Chemistry

    Show that the reaction caco3 ->cao+co2 is not a redox reaction
  18. chemistry

    For the reaction HCO3- H+ + CO32-, ΔG° = +59.0 kJ/mol at 298.15 K. Find the value of K for the reaction
  19. sun shine high shcool

    during the reaction the temperature of 50cm of solution tell by 10centigrade, how much energy did the reaction take in?
  20. chemistry

    what is the oxidation half-reaction in the following chemical reaction? fe(s) + 3 agno3 -> ag + fe(no3)3
  21. chemistry

    balanced reaction for reaction between ferrous sulphate and nittric acid
  22. chemistry

    Given the reaction 1/2 N2( g) + 3/2 H2 (g) ___> NH3 (g) +11.0kcal.Is this reaction exothermic or endothermic?
  23. science

    Given the following reaction, with Kp=1.05 at 250 degrees C what is Kc? The reaction is PCl5 to PCl3+Cl2
  24. chemistry

    for an exotherimic reaction incresing the reaction temperature results in a (n)___k ?
  25. chemistry

    What type of reaction would CO2 + H2O --> H2CO3 be I think it would be synthesis reaction?
  26. Chemistry

    X(g)+ 2Y(s) + 3Z(g) ⟶ 2L(g) + 4T(g) If this reaction occurs in one step, what is the order of this reaction? I am not even sure what this means. Could someone explain?
  27. Science at National University OF Samoa

    2-bromobutane heat with 2M NaOH. What is the observation and the chemical reaction for the reaction?
  28. Chemistry

    What chemical compound is formed in the reaction when 6M HCl and 1M NaOH is reaction?
  29. Chemistry

    How does the activation energy of an uncatalyzed reaction compare with that of the catalyzed reaction?
  30. Physics

    A ball is fired from the ground with an initial speed of 1.36 103 m/s (approximately four times the speed of sound) at an initial angle of 49.0° to the horizontal. Neglect air resistance.
  31. Physics - 2-D kinematics

    A soccer ball is kicked with an initial horizontal velocity of 20 m/s and an initial vertical velocity of 16 m/s. I've calculated: Initial Speed: 25.61 m/s Angle: 38.66 degrees Maximum Height it reaches: 13.06 m Distance kicked: 65.29m NOW I NEED: What is
  32. math

    after passing therough a material t centimeters thick, the intensity I(t) of a light beam is given by I(t) =(4^-ct)Io, where Io is the initial intensity and c is a constant called the absorption factor. Ocean water absorbs light with an absorption factor
  33. HELPP CHEMM

    Heat of fusion of ice lab Initial mass of empty cup calorimeter 9.55g Initial mass of water 200.15g Initial mass of ice + water 209.7g Initial temp of water 41.9°C Initial mass of ice 26.9g Final mass of cup 9.55g Final mass of water 227.05g Final mass of
  34. 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.
  35. 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
  36. Separation of Racemate- Chemistry Lab

    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
  37. chemistry

    I was having trouble with this problem. initial pressure for the compounds involved in the reaction displayed were determined to be P(CO(g)) = 0.5794 atm, P(H2O(g)) = 0.5662 atm, P(CO2(g)) = 0.7950 atm, P(H2(g)) = 0.2754 atm. Calculate the value of the
  38. Chemistry

    the type of reaction in a voltaic cell is best described as 1.spontaneous oxidation reaction only 2.nonspontaneous oxidation reaction only 3.spontaneous oxidation-reduction reaction 4.nonspontaneous oxidation-reduction reaction i know its spontaneous, but
  39. Physics

    Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are
  40. physics

    Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are
  41. physics

    Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are
  42. 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 these are
  43. Chemistry

    At 573 K, gaseous NO2(g) decomposes, forming NO(g) and O2(g). If a vessel containing NO2(g) has an initial concentration of 1.9 × 10−2 mol/L, how long will it take for 75% of the NO2(g) to decompose? The decomposition of NO2(g) is second-order in the
  44. Chemistry

    A calorimeter, with calorimeter constant 7.31 J K–1, was used to measure the heat of reaction for mixing 100.0 mL of 0.100 M Ag+ with 100.0 mL of 0.100 M Cl–. The temperature change was +0.770 K for the 200.0 g of solution (specific heat capacity =
  45. physics - stopping distance

    when a driver brings a car to a stop by breaki.g as hard as possible the stopping can be regarded as the sum of reaction distance and breaking distance. tje following data are given, v1 m/s contains 10,20,30. reaction distance are 7.5, 15, 22.5. the
  46. chemistry

    In the REDOX reaction in basic solution Zn-->Zn(OH)4+H2 I know that the first half reaction is 4H20+Zn-->Zn(OH)4 +4H+e but the second one is either 2e+2H2O--->H2+2OH (WHICH IS THE ANSWER GIVEN ON THE WORKSHEET) OR 2e+2H-->H2 I think both leads to the same
  47. 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 the
  48. chemistry

    A reaction starts with 1.00 mol each of PCl3 and Cl2 in a 1.00-L flask. When equilibrium is established at 250 degree Celsius in the reaction PCl3(g)+ Cl2(g)--> PCl5(g), the amount of PCl5 present is 0.82 mol. What is Kc for this reaction?
  49. 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 foryour
  50. 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
  51. physics

    A projectile, fired with unknown initial velocity, lands 18.4 s later on the side of a hill, 3290 m away horizontally and 409 m vertically above its starting point. (Ignore any effects due to air resistance.) (a) What is the vertical component of its
  52. Algebra

    The height, in meters, of a projectile can be modeled by h= -4.9t^2 + vt + s where t is the time (in seconds) the object has been in the air, v is the initial velocity (in meters per seconds) and s is the initial height (in meters). A soccer ball is kicked
  53. physics

    a ball is projected at an angle with an initial velocity of 8m/s and an initial vertical velocity of 29.4m/s. Show trajectory diagram. Determine: a) displacement b)height at peak c)final speed
  54. Physics

    A basketball is shot from an initial height of 2.4 m with an initial speed (v0 = 12 m/s) directed at an angle (35 degrees) above the horizontal. Additional information: Height of the basket is 3.05 m Find how far away the player is standing.
  55. Chemistry(Please check)

    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 chose 2 as the answer. Is this correct?
  56. 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?
  57. 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
  58. 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?
  59. 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!
  60. 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?
  61. 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?
  62. 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?
  63. Enthalpy

    Consider the following reaction: 2 Mg + O2 → 2 MgO ΔH rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg. How do I set this up correctly?
  64. Enthalypy Reaction

    What is the standard enthalpy of reaction for the following chemical reaction? CO2(g) + 2KOH(s) --> H2O(g) + K2CO3 (s) Express your answers numerically in kJ.
  65. 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
  66. chemistry

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

    Which of these shows the correct balanced half-reaction for the following? The reaction takes place in acidic solution. C2O42–(aq) → CO2(g)
  68. 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?
  69. 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?
  70. 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?
  71. 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.
  72. 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.
  73. science

    in a certain chemical reaction, two reactants undergo change to form two products why cant you determine what type of reaction occurred from this information
  74. 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.
  75. chemistry

    Represent this reaction with a balance chemical equation. Solid aluminium hydride is formed by a combination reaction of its two elements.
  76. 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
  77. Chemistry

    Consider the reaction when aqueous solutions of manganese(II) sulfate and barium bromide are combined. The net ionic equation for this reaction is:???
  78. 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?
  79. sofunda

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

    The reaction below has an equilibrium constant of Kp=2.26×104 at 298 K. CO(g)+2H2(g)⇌CH3OH(g) Calculate Kp for the reaction below. 3CH3OH(g)⇌3CO(g)+6H2(g)
  81. Chemistry1412

    The reaction below has an equilibrium constant of Kp=2.26×104 at 298 K. CO(g)+2H2(g)⇌CH3OH(g) Calculate Kp for the reaction below. 3CH3OH(g)⇌3CO(g)+6H2(g)
  82. 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)
  83. 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
  84. physics

    calculate the range of the projectile using the initial speed and angle. use 9.8m/s. Initial speed 18m/s and the is 75 degrees. I came up with 8.29 is that right
  85. 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
  86. chemistry

    Calculate the temperature at which it is thermodynamically possible for C (s) to reduce iron(III) oxide by the reaction: 2Fe2O3 (s) + 3 C (s) ---> 4Fe (s) + 3CO2 I don't need a specific answer, but I'm not sure how to approach the problem. I'm assuming it
  87. Chem

    4NH3(g) + 3O2(g) -> 2N2 + 6H20, K=10^80 @ certain temp initially, all the reactants and products have concentrations equal to 12M. At equilibrium, what is the approximate concentration of ammonia?
  88. Chem

    4NH3(g) + 3O2(g) -> 2N2 + 6H20, K=10^80 @ certain temp initially, all the reactants and products have concentrations equal to 12M. At equilibrium, what is the approximate concentration of ammonia?
  89. Chem

    4NH3(g) + 3O2(g) -> 2N2 + 6H20, K=10^80 @ certain temp initially, all the reactants and products have concentrations equal to 12M. At equilibrium, what is the approximate concentration of ammonia?
  90. Chemistry

    A 100.00 ml of volume of 0.500 M HCl was mixed with 100.00 ml of 0.500 M KOH in a constant pressure calorimeter. The initial temperature of individual acid and base was 23.0 oC. The final temperature after mixing was 25.5 oC. The specific heat of the
  91. Health

    What is physical stress? A. A physical reaction to the heart to various triggers B. A physical reaction of the body to various triggers C. A physical reaction of the soul to various triggers D. A physical reaction of the mind to various triggers B
  92. 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
  93. Chemistry

    The free energy profile as the reaction goes from reactants to products is a straight diagonal line from 50 kj/mol to 80 kj/mol. Is the reaction exothermic or endothermic? Does the reaction involve only pure solids and liquids? Is the equilibrium constant
  94. General Chemistry

    NH4+ + NO2- = N2 + 2H2O A reaction is run, and the liberated N2 gas is collected in a previously evacuated 500 mL container. After the reaction has gone on for 750 seconds, the pressure of N2 in the 500 mL container is 2.77 x 10^-2 atm , and the
  95. chem

    N2H4 is decomposed in a closed container according to this reaction: N2H4 → N2 + 2H2 . If the temperature is constant and the initial pressure of N2H4 is 800mm, what will the pressure in millimeters be after the decomposition to N2 + 2H2? Im having
  96. Maths

    Experiments show that the concentration of substance X in a first order chemical reaction at future time (in seconds) t i.e. [X] is described by the following differential equation: d[X]/ dt= .001[X], find: (a) Find an expression for the concentration
  97. Chem

    The initial concentration for the compounds involved in the reaction displayed were determined to be [NO2(g)] = 1.243 mol/L, [N2O4(g)] = 0.2578 mol/L. Calculate the value of the equilibrium constant (Kc) at 500.0 K if the equilibrium concentration of
  98. 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
  99. Chemistry

    A student titrates HCl with 0.0125M KOH. Starting with 50.00 ml of the acid it takes 40.0 ml of base to reach equilavence point. A. What is the concentration of the HCl? B. What is the initial pH of the acid solution? C. What is the pH of the reaction
  100. Chemistry

    A student titrates HCl with 0.0125M KOH. Starting with 50.00 ml of the acid it takes 40.0 ml of base to reach equilavence point. A. What is the concentration of the HCl? B. What is the initial pH of the acid solution? C. What is the pH of the reaction