1. Science

    Which of the following best describes the result of using a catalyst in a chemical reaction? A. The yield of product is increased. B. A more desirable product is often formed. C. A greater amount of heat energy is released by the reaction. D. The reaction
  2. Chem

    With which of the following will the weak acid HCHO2 react? If a reaction occurs, write the balanced molecular equation. If no reaction occurs write the left half of the reaction and use "NR". Do not include physical states in your answers. KOH: NH3:
  3. Chem

    I just need to know if I did the problem correctly. The decomposition of phosphine, a very toxic gas, forms phosphorus and hydrogen in the following reaction: 4PH3(g) → P4(g) + 6H2(g) If the instantaneous rate of the reaction with respect to PH3 is -0.41
  4. chemistry

    In general, reaction rates double when the temperature is increased by 10ºC. The temperature of a reaction is increased by 40ºC. The rate of the reaction will increase by a factor of ____? is it 16?
  5. chemistry

    Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.
  6. reaction rate help

    In general, reaction rates double when the temperature is increased by 10ºC. The temperature of a reaction is increased by 40ºC. The rate of the reaction will increase by a factor of ____? is it 16?
  7. Chemistry

    What are the correct and accurate products for the following ion combination reaction? Then write the ionic form of the reaction and the net ionic form of the reaction. K2CO3 + CaCl2 ->
  8. chem

    true or false?? a)If there are no changes in the oxidation state of the reactants or products of a particular reaction, that reaction is a redox reaction. false? b)A reducing agent gets oxidized as it reacts. true?
  9. physics

    ll is thrown vertically upward with an initial speed of 16 m/s. Then, 0.65 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 27 m/s. How far above the release point will the ball and stone pass each
  10. physics

    ll is thrown vertically upward with an initial speed of 16 m/s. Then, 0.65 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 27 m/s. How far above the release point will the ball and stone pass each
  11. physics

    A first object is thrown vertically upward with some initial speed and some initial height above the ground. Simultaneously, a second object is thrown straight down with the same initial speed and same initial height above the ground. Before the second
  12. physics

    A shell is fired from the ground with an initial speed of 1.53 ✕ 103 m/s at an initial angle of 55° to the horizontal.
  13. physics

    A ball is thrown vertically upwards and returns to its initial position in 6.0 second. What is its initial speed
  14. Physics

    Bryant is fired from a cannon with an initial speed of 14 m/s. If his mass is 80 kg what is his initial kinetic energy?
  15. AP Calculus AB

    An object has a constant acceleration of 40 ft/sec2, an initial velocity of -20 ft/sec, and an initial position of 10 ft
  16. Math

    Find the specific solution for the following differential equations: a) (dy/dx)^2 - x^4 = 0 given the initial value y(1) = 0 b) dy/dx = ysinx given the initial value y(pi) = 1
  17. chemistry

    1(a) when 25.0ml of 0.500 mol.dm3 H2SO4(AQ) SOLUTION IS added to 0.025dm3 of 1.00 moldm3 KOH SOLUTION , THE TEMPERATURE OF THE REACTION MIXTURE RISES FROM 23.50 CELCIUS TO 30.17 CELCIUS . THE SPECIFIC HEAT CAPACITY AND DENSITY OF WATER 4.20j.g.celcius and
  18. Chemistry

    The standard free energy of activation of a reaction A is 73.4 kJ mol–1 (17.5 kcal mol–1) at 298 K. Reaction B is one million times faster than reaction A at the same temperature. The products of each reaction are 10.0 kJ mol–1 (2.39 kcal mol–1)
  19. Equilibrium

    The following reaction has an equilibrium constant (Keq) of 160. 2 NO2(g) 2 NO(g) + O2(g) What will be the reaction quotient (Q) and in which direction will the reaction proceed if the partial pressure of NO2 is 5.0*10^-4 atm, NO is 0.080 atm, and O2 is
  20. hh

    When the baseball is shot straight upward with an initial speed of 20 \rm m/s, what is the maximum height above its initial location?
  21. Physics

    in an impulse/ change in momentum problem where mv(final)-mv(initial)=Ft if the initial velocity is zero can i cancel out the masses?
  22. Physics

    A projectile is fired with an initial speed v0 at t = 0. The angle between the initial velocity v0 and the horizontal plane is . x y v0 yma
  23. chemistry

    Consider the reaction 2 NO2 (g) ⇌ 2 NO (g) + O2 (g). If the initial partial pressure of NO2 (g) is 3.0 bar, and x is the equilibrium pressure of O2 (g), what is the correct equilibrium relation?
  24. chemistry

    The reaction SO2 + H2O =H2SO4 Is the last step in the commercial production of sulfuric acid . the enthalpy change for this reaction is -227 KJ . In designing a sulfuric acid plant is it necessary to provide for heating or cooling of the reaction mixture ?
  25. PHYSICS Collision of two Balls Momentum!! HELP

    A ball A of mass .202 kg is moving at a velocity of 2.0 m/s toward a ball B that is at rest. (a) Calculate the initial momentum for Ball A and Ball B. (b) Calculate initial Kinetic energy for Ball A and Ball B. My doubt since its asking for initial moment
  26. PHYSICS Momentum!! Collision HELP

    A ball A of mass .202 kg is moving at a velocity of 2.0 m/s toward a ball B that is at rest. (a) Calculate the initial momentum for Ball A and Ball B. (b) Calculate initial Kinetic energy for Ball A and Ball B. My doubt since its asking for initial moment
  27. Physics

    A projectile is shot from the ground at an angle of 60 degrees with respect to the horizontal, and it lands on the ground 5 seconds later. Find: a. the horizontal component of initial velocity b. the vertical component of initial velocity c. initial speed
  28. Physics

    A projectile is shot from the ground at an angle of 60 degrees with respect to the horizontal, and it lands on the ground 5 seconds later. Find: a. the horizontal component of initial velocity b. the vertical component of initial velocity c. initial speed
  29. chemistry

    Examine the scenario. Chemical Reaction A and Chemical Reaction B involve the same two reactants. Chemical Reaction A is performed in a hot container, while Chemical Reaction B is performed in a cold container. Which of the answer choices correctly
  30. chemistry help

    For the reaction shown, find the limiting reactant for each of the following initial amounts of reactants? 2Na(s)+Br2(g) ---->2NaBr(s) 1. 2mol Na, 2mol Br2 2. 1.8mol Na, 1.4mol Br2 3. 2.5mol Na, 1mol Br2 4. 12.6mol Na, 6.9 mol Br2
  31. Chem

    K so this time it is basic concept and I am suppose to guess what happens, so I've written the cause but I have also written my answer to the reaction and effect. so for: A + B C stress: A is increased reaction: forward effect:[A]increased [B] inc [C]inc
  32. College algebra

    When a ball is thrown up into the air, it makes the shape of a parabola. The equation S= -5t^2 + v*t + k gives the height of the ball at any time, t in seconds, where “v” is the initial velocity (speed) in meters/sec and “k” is the initial height
  33. Ap Chemistry

    I have no idea where to start with this problem: A certain reaction has the following general form: aA -> bB At a particular temperature and (A)o = 2.00(10^-2)M, concentration versus time data were collected for this reaction, and a plot of In(A) versus
  34. AP Chemistry

    I have no idea where to start with this problem: A certain reaction has the following general form: aA -> bB At a particular temperature and (A)o = 2.00(10^-2)M, concentration versus time data were collected for this reaction, and a plot of In(A) versus
  35. chemistry

    A reaction is first order and it takes 324 minutes for the reaction to be 50.0% complete. How long will it take for the reaction to be 85.0% complete at the same temperature? The answer is 887 minutes but I have no idea how he got that? help
  36. Calc

    The temperature of a chemical reaction, t seconds after the reaction starts, is given by: T(t)= 20+5.25t^.75 degrees F , What is the average temperature during the whole process, if the reaction lasts for 4 minutes and 16 seconds ?
  37. Physics

    A soccer ball is kicked with an initial speed of 12.2 m/s. After 0.497 s it is at its highest point. What was its initial direction of motion?
  38. Physics

    A soccer ball is kicked with the initial speed of 10.7m/s . After 0.780s it is at its highest point. What was its initial direction of motion?
  39. CHEMISTRY

    1. Give reasons for your choice. 2. Give reasons for rejecting other options. The reaction C(s) + O2(g) CO2(g) + heat reaches equilibrium in a closed reaction vessel. Which one of the following actions causes the equilibrium to shift to the right ? A
  40. Chemistry

    The following reaction mechanism has been proposed for a reaction: (slow) NO2 + NO2-> NO3 + NO (fast) NO3 + CO -> CO2 + NO2 A. Write the equation for the overall reaction from the mechanism above. B.Write the rate law for the reaction
  41. Chemistry

    The following reaction mechanism has been proposed for a reaction: (slow) NO2 + NO2-> NO3 + NO (fast) NO3 + CO -> CO2 + NO2 A. Write the equation for the overall reaction from the mechanism above. B.Write the rate law for the reaction
  42. Chemistry

    The following reaction mechanism has been proposed for a reaction: (slow) NO2 + NO2-> NO3 + NO (fast) NO3 + CO -> CO2 + NO2 A. Write the equation for the overall reaction from the mechanism above. B.Write the rate law for the reaction
  43. physics

    x=x0+v0t+1/2at^2. Assuming that x0=0, a=2, and x=h, solve for t in terms of initial v and h? x0 mean initial value of x same with v0
  44. chem plzzz help

    okay so im doing pre lab questions on reaction rates I have a chart labeled effects of varying concentration in reaction #1 flask A contains 7.50mL of .200 M KI , none of .20M KCI, 5.00 mL of .0050 M S2O3^2-, 1 drop of starch. Flask B contains 7.5mL of
  45. AP CHEM-- check work?

    How many moles of ATP must be converted to ADP by the reaction ATP(aq) + H2O ---> ADP(aq) + HPO4-2(aq) + 2H+(aq) delta-G*= -31 kJ to bring about a nonspontaneous biochemical reaction in which delta-G*= +372 kJ? I did my work out like this..: 372 kJ x 1
  46. Chemical Kinetics

    The kinetics of the catalytic decomposition of NH3 into N2 and H2 on a hot tungsten filament at 1100 °C was investigated by Kunsman. He measured the times (t1/2) required for half of NH3 to decompose at different initial NH3 pressures, as shown below: P
  47. Chemistry

    The solubility products of Fe(OH)2 and Fe(OH)3 are 10^-17 and 10-38 respectively. If the concentrations of Fe2+ and Fe3+ are each 10^-5, at what pH will each hydroxide just begin to precipitate?
  48. chemistry

    Calculate the concentrations of all species present in a 0.32 M solution of ethylammonium chloride (C2H5NH3Cl).
  49. Chemistry

    Calculate the percent ionization of benzoic acid at the following concentrations: 0.00014 M i got 68% but it says its wrong
  50. CHEMISTRY

    Assuming equal concentrations , rank these solutions by pH. RbOH(aq), NH3(aq), HF(aq) HBr(aq), Ca(OH)2(aq).
  51. Chemistry

    DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 Help!
  52. Science

    Do you know at what level PCE concentrations are of concern? Is 8,300 PPB a major problem?
  53. physics

    An ideal gas has an initial volume of 500 cm3 , an initial temperature of 20◦C, and an initial pressure of 2 atm. What is its final pressure if the volume is allowed to expand to 1000 cm3 while the temperature increases to 60◦C?
  54. physics

    A soccer ball is kicked from the ground with an initial speed of 14.5 m/s. After 0.272 seconds, ts speed is 12.4 m/s. (A) Give a strategy that will allow you to calculate the ball's initial direction of motion. (B) Use your strategy to find the initial
  55. Chemistry

    Nitrogen and oxygen can react directly with one anotheer to produce nitrogen dioxide according to N2(g) + 2O2(g) --> 2NO2(g) The reaction may also be imagined to take place by first producing nitrogen oxide N2(g) + O2(g) --> 2NO(g) which then produces NO2
  56. Chemistry

    HELP! we just started kinetics and i have no clue how to solve this problem. For the reaction between reactants A and B below, if 4.925 moles of A is placed into a flask with excess B it is found that the amount of A remaining after 6.85 seconds is 2.737
  57. Chemistry

    Ethane, C2H6, forms ·CH3 radicals at 700.°C in a first-order reaction, for which k = 1.98 h-1. (a) What is the half-life for the reaction? (b) Calculate the time needed for the amount of ethane to fall from 1.00 10-3 mol to 2.48 10-4 mol in a 500. mL
  58. Physics

    Initial Statement: A soccer ball is kicked with an initial horizontal velocity of 15 m/s and an initial vertical velocity of 14 m/s. 1) What is the initial speed of the ball? 20.518 2) What is the initial angle θθ of the ball with respect to the ground?
  59. AP Chemistry

    For the system 2SO2(g) + O2(g) 2SO3 (g), change in enthalpy is negative for the production of SO3. At a particular temperature, 8.00 moles of sulfur dioxide and 10.00 moles of sulfur trioxide are introduced into a 2.00 L container. The system is allowed to
  60. physics

    A projectile is fired through the air. It is launched from the ground, and travels without interference from wind or air resistance, landing on a raised platform above the field. Compare the following values: 1-Initial speed vs. final speed: 2-Initial
  61. 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
  62. 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
  63. physics

    An object with mass of 7kg was thrown down with initial velocity 10m/s and reached the ground in 10s. What was the the initial height
  64. Calculus

    In a chemical reaction, substance A combines with substance B to form subtance Y. At the start of the reaction, the quantity of A present is a grams, and the quantity of B present is b grams. Assume a is less than b. At time t seconds after the start of
  65. Chemistry - check answer

    A 20.0 L reaction vessel contains 0.016 moles CO2, 1.05 moles of CO, and 2.00 moles of C. The mixture is approaching the following equilibrium: CO2(g) + C(s) 2CO(g) a) Calculate the reaction quotient Q. b) If value of K is 1.17, predict which direction the
  66. Science

    1. what is a single replacement reaction A. A reaction in which two or more substances react to form a single substance*** B. A reaction in which one element takes place the place of another element in a compound. C. A reaction in which a compound breaks
  67. chemistry

    Please help! 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?
  68. chemistry

    What change do you expect if the value of the reaction quotient is greater than the value of the equilibrium constant? A. The rate of the forward reaction is greater than the rate of the reverse reaction. More reactant forms. B. The rate of the forward
  69. chemistry

    What mass of benzoic acid can be made from a reaction where 4.87g benzyl alcohol is combined with 300mL of bleach? The reaction is conducted in water and dichloromethane. Describe a method of separating the benzoic acid from the sodium chloride byproduct
  70. Chemistry

    Consider the reaction N2(g)+3H22NH3(g). What is the effect of decreasing the volume on the contained gases The reaction shifts toward the product gas The system reacts by increasing the number of gas molecules*** the pressure on the gases decreases
  71. chemistry

    What mass of benzoic acid can be made from a reaction where 4.87g benzyl alcohol is combined with 300mL of bleach? The reaction is conducted in water and dichloromethane. Describe a method of separating the benzoic acid from the sodium chloride byproduct
  72. Chemistry

    1) Using a table of standard electrode potentials (such as the one in your textbook), calculate the standard cell potential for a cell made by placing a zinc electrode in a Zn2+(aq) solution which is connected by an electrolyte to a Ag+(aq) solution
  73. Engineering Physics

    A car and a train move together along straight, parallel paths with the same constant cruising speed v(initial). At t=0 the car driver notices a red light ahead and slows down with constant acceleration -a(initial). Just as the car comes to a full stop,
  74. Math

    Recall that the equation for the horizontal distance h in feet of a projectile with initial velocity v0 and initial angle theta is given by h=v0^2/16 sin theta cos theta . a. Assume the initial velocity is 60 ft/second. What initial angle will you need to
  75. Chemistry!!!!

    1. For a reaction mechanism to be plausible, what 2 criteria must be met? 2. The reaction between CO and NO2 to produce NO and CO2 is thought to occur in 2 steps. NO2 + NO2 ====> NO + NO3 NO3 + CO =====> NO2 + CO2 The experimental rate law is, R=k[NO2]2
  76. Chemistry!!!!

    1. For a reaction mechanism to be plausible, what 2 criteria must be met? 2. The reaction between CO and NO2 to produce NO and CO2 is thought to occur in 2 steps. NO2 + NO2 ====> NO + NO3 NO3 + CO =====> NO2 + CO2 The experimental rate law is, R=k[NO2]2
  77. chemistry

    The reaction described by this equation O3(g) + NO(g) -- O2(g) + NO2(g) has the following rate law at 310 K. rate of reaction = 3.0x10^6 M^-1 s^-1)[O3][NO] Given that [O3]=2.0× 10–4 M and [NO]=2.0× 10–5 M at t=0, calculate the rate of the reaction at
  78. 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
  79. chemistry

    Does an insoluble solid dissociate into ions? Is the reaction reversible? Will an equilibrium reaction form when a chemical reaction forms an insoluble solid? Why, or why not?
  80. Heeelllppp in chemistry plzzzz

    the reaction BrO3- + 3SO3 2- ---> has the rate law r= k[BrO3-][SO3 2-]. what is the order of the reaction with the respect to each reactant? wat s the overall order of the reaction?
  81. Plzz help me

    the reaction BrO3- + 3SO3 2- ---> has the rate law r= k[BrO3-][SO3 2-]. what is the order of the reaction with the respect to each reactant? wat s the overall order of the reaction?
  82. chemistry

    (AAAAA)The standard reduction potentials of lithium metal and chlorine gas are as follows: (for Li, reduction potential is -3.04, for Cl it is 1.36) In a galvanic cell, the two half-reactions combine to 2Li{+](s) + Cl{-}2(g) --> 2Li{+}Cl{-}(aq) Calculate
  83. Chemistry

    Just a few questions about rates of reaction. A) Why are the units for average and instantaneous rates the same? -because they are both measures of how quickly a reaction is occuring per unit time B) For a given set of data, two students determined
  84. chemistry

    sodium metal reacts with hydrogen gas to yield solid sodium hydride ( NaH ). A reaction mixture contains 10.00 g sodium metal and 0.235 g of hydrogen gas. write a balanced chemical equation for this reaction? what is your limiting reactant? what is your
  85. physics

    a ball is thrown at an initial angle of 37 and initial velocity of 23.0 m/s reaches a maximum height h, as shown in the Figure. With what initial speed must a ball be thrown straight up to reach the same maximum height h?
  86. Physics

    2)Identify the initial and final states if an electron in hydrogen emits a photon with a wavelength of 1282.0 nm. Enter the initial state first
  87. Finance

    what is the initial rate of return for the following project: An initial outlay of 9,500 resulting in a single cash flow of 16,281 in 7 years
  88. Chemistry

    2A + B2 + C --> A2B + BC Run # Initial Rate (M-1s-1) (A)o (B)o (C)o 1 1.6 x 106 1.2 M 1. x 10-2 M 1.0 M 2 1.6 x 106 2.4 M 1. x 10-2 M 1.0 M 3 3.2 x 106 1.2 M 2. x 10-2 M 1.0 M 4 6.4 x 106 1.2 M 1. x 10-2 M 2.0 M What would be the rate-law expression of the
  89. chemistry

    CH3OH(g) ----> CO(g) + 2H2 (g) (delta H =+90.7k) A) is heat absorbed or released in the course of this reaction? b) calculate the amount of heat transferred when 45.0g of CH3OH(g)is decomposed by this reaction at constant pressure. c) for a given sample of
  90. College Physics

    A single resistor is wired to a battery.Define the total power dissipated by this circuit as P initial. What is the power, in terms of P initial, dissipated by this circuit? Power = P initial.
  91. Chemistry

    Part 1 of 2 Write the balanced molecular equation for the reaction between iron metal (the nail) and aqueous copper II sulfate and classify this reaction. Include the states: solid (s), liquid (l), aqueous (aq), or gas (g). Use your observations to help
  92. Chemistry

    write 2-3 sentences describing and identifying the type of chemical reaction that occurs when Fe^2+ reacts with potassium permanganate and specifying the type of solution required for the reaction to occur I don't know what type of reaction this is or what
  93. Chemistry

    Calculate the molar H3O and ClO3 concentrations of a .28 M solution of perchloric acid (HClO3)?
  94. Chemistry

    What can you conclude about the relative equilibrium concentrations of CrO4 ion in each of the solutions 0.1M K2Cr2O7 and 0.1M K2CrO4?
  95. Chemistry

    What ratio of molar concentrations of sodium acetate to acetic acid can buffer a solution at a pH of 4.89?
  96. Chemistry

    What are the concentrations of acetic acid (pKa = 4.76) and acetate in a buffer solution of 0.15 M at pH 4.5? Please help me do this problem. I have no idea how to do it.
  97. Chemistry

    DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 is 7.1x10^16
  98. chemistry

    Calculate the concentrations of all species present C6H5N2, C6H5NH3+ OH^-, and H3O^+}) in a 0.14 M solution of aniline.
  99. Chemistry

    Calculate the concentrations of Cd2 +, [Cd (CN) 42] and CN at equilibrium when they dissolve 0, 42mol of Cd(NO3)2, molarity= 2.50 M Kf =7.1x10^16
  100. chemistry

    what are the equilibrium concentrations of Pb2+ and F- in a saturated solution of lead (II)flouride if the Ksp for PbF2 is 3.2*10^-8?