1. Chemie

    for the reaction at 20 C NH3 (aq) + H+ (aq) <----> NH4+(aq) the equilibrium constant is calculated to be K=4.5 x 108
  2. Chemistry

    If u place a metal cube in beaker as a catalyst, what effect will it have on the reaction? And why?
  3. Chemistry

    your reactants are an element and compound that is not not a hydro carbon. What type of reaction do you probably have??
  4. chemistry

    estimate the enthalpy change for the following reaction: OF2 + H2O = O2 + 2HF
  5. Chemistry!

    What is theoretical yield when 15.6g of bromobenzene & 8.3g of methyl benzoate is used in a Grignard reaction.
  6. Chemistry

    What is the complete redox reaction of KMnO4 against (NH4)2Fe(SO4)2
  7. chem

    what is the major product of this reaction CH2=CH-CH2CH3+H2O H2SO4
  8. chemistry

    1.10 is allowed to react with 9.57 , producing 2.50 . What is the theoretical yield for this reaction under the given conditions?
  9. Chemistry

    Balance the equation and write the reaction-quotient expression, Qc. U(s) + F2 (g) <----> UF6 (g)
  10. biology

    How would lgiht reaction be affected if there were no concentration gradient across the thlykoid membrane?
  11. chemistry

    What is the balanced equation of the reaction between ammonium ion amd water?
  12. Chemistry

    Write a balanced chemical reaction showing how the 4.99 g Sn dissolves in HNO3.
  13. Science

    Chemistry: What is the general formula for a chemical reaction? reactants >> products
  14. chemistry

    When you mix baking soda with vinegar is the reaction endothermic or exothermic?
  15. Chem Help

    What is the heat of reaction when 4 moles of carbon monnozide are buened in oxygen?
  16. Chemistry

    If SiO_2 undergoes a double-displacement reaction with HF, what is the balanced equation?
  17. science

    what will happen if you increase the surface area of a solid in a chemical reaction?
  18. Organic Chemistry

    what is the major product of a reaction with 1-butene and Br2 in water?
  19. Chemistry

    Write an equation for the half-reaction in which a potassium atom, K, is oxidized. A) K + e- ----> K+ B) K ----> K+ + e- C) K- ----> K+ + 2 e- I think A
  20. chem

    Chromium(III) chloride(aq) + potassium sulfide(aq) what are the products of this reaction
  21. science

    write an equation relating the concentration of a reactant A at t=0 to that at t= t for a first order reaction.
  22. Chemistry

    What kind of reaction is it when the reactants produce carbon dioxide and water
  23. Environmental science 11th

    Describe how energy is produced in a nuclear reaction.
  24. chemistry

    what is the limiting reagent in a reaction between copper sulfate and barium nitrate?
  25. Chem

    What is the enthalpy for the following reaction? overall: C2H4+H2O--->C2H5OH is -1411kJ correct??
  26. Chemistry

    3.00 g of Zn is allow to react with 1.75 g CuSO4 . calculate how many grams of Zn will remain after the reaction is complete ?
  27. chemistry

    write the reaction for the neutralization of nitric acid with calcium hydroxide.
  28. AP Chemistry

    What is the redox reaction of (i don't understand how to do this): MnO4-(aq) + H2O2(aq) -> Mn2+(aq) + O2(g)
  29. Chemistry

    CH4 + Cl2 → CH4Cl + HCl Is this a double replacement reaction? I believe it is but am not entirely sure.
  30. Chemistry

    What is the formula of the precipitate formed from the precipitation reaction of Li2CO3 and ZnCl2?
  31. Cemistry

    Why do we have to heat KMnO4 solution when we have to do the titration with the oxalate ions for such reaction?
  32. chemistry

    By what factor is the rate of a reaction changed if an enzyme lowers the Ea by 9.0 kJ/mol at 37°C?
  33. Chemistry

    Which reaction would occur more readily? Why? 1) Mg + Cl2 --> MgCl2 2) 2Mg + O2 --> MgO Thanks!
  34. Help

    Fibrin is produced when the blood components called what start chain reaction
  35. Chem

    How does the collision model explain the ffect of concentration on the reaction rate?
  36. Chemistry

    Calculate the equilibrium constant, k a reaction with delta G= -32.5 kj/mol at 25 degrees C
  37. chemistry

    why the increasing in substrate concentration increase in the rate of reaction of enzymes.
  38. Chemistry

    If 2.5x10^-3 moles of O2 were produced in the reaction, how many grams of H2O2 had to react?
  39. Stoichiometry

    if you have 66.6g NH3, how many grams of F2 are required for a complete reaction? please show work!!!!!
  40. chemistry

    what is an example of autocatalysis? what will the graph of the rate of an autocatalytic reaction versus time look like?
  41. Chem

    How does the collision model explain the ffect of concentration on the reaction rate?
  42. chemistry

    A student generates H2(g) over water using the reaction between zinc and hydrochloric acid Zn(s)+ 2HCl(aq)---> ZnCl2(aq)+ H2(g) Data: Mass of vial and zinc 15.5082 mass of vial 15.3972 mass of zinc 0.111 final burette reading 45.30mL barometric
  43. chemistry

    I am doing a home lab experiment about acid-base neutralization. I just need a little help to see if I am doing it correctly. I completed the experiment and recorded the data. We were to add 25 ml of vinegar and the 1 ml of cabbage indicator, the add i ml
  44. Finance

    The company bought some land three years ago for $3.8 million in anticipation of using it as a toxic dump site for waste chemicals, but it built a piping system to safely discard the chemicals instead. The land was appraised last week for $4.6 million. In
  45. Chemistry

    For my chemistry lab, I reacted Mg powder with HCl to create H2 gas. I measured the volume of H2 gas created by salt water displacement by reading off an inverted test tube. I measured 14.0 mL and calculated the percent yield (used PV=nRT to find
  46. physics As

    The table below shows how the braking distance x for a car depends on its initial speed u u / ms-1 5.0 10 20 4 x / m 2.0 8.0 32 128 the reaction time of a driver is 0.60s. Calculate the sopping distance of the car when u= 30ms-1. The mark scheme says:

    The autocatalytic reaction of A to form Q is one that accelerates with conversion. An example of this is shown below: A+Q~Q+Q However, the rate decreases at high conversion due to the depletion of reactant A. The liquid feed to the reactor contains 1 mol
  48. check.

    12. The substance produced by the light-reaction and used in the light-independent reaction is A. water B. oxygen C. hydrogen D. carbon dioxide hi there so I belive that the answer is b or d but i am leaning more toward b is that correct? Your question is
  49. Motion in 2d

    A projectile is fired at 37.0° above the horizontal with an initial speed of 65.0 m/s. Find it's range. Well what I did was get the x and y components for the vector by: V-subX= (65 m/s) (cos(37°)) = 51.91 V-subY= (65 m/s) (sin(37°)) = 39.11 I'm not
  50. physics

    You are the first person to land on the planet Mars where the gravitational acceleration is 3.71 m/s2. You jump with joy with an initial speed of 4.30 m/s. How high do you rise above the martian surface?
  51. finance

    investment requires an initial oulay of 105,000 and will generate cash inflow of 20000 for 11 years. What is the NPV using discount rate of 8%
  52. physics

    A lead pellet is propelled vertically upward by an air rifle so that its initial speed is 49 m/sec. Find its total time of flight.
  53. Physics

    how long will it take a bullet fired from a cliff at an initial velocity of 700m per second at an angle of 30 Degree below the horizontal to reach the ground 200m below?answer
  54. physics

    A football is thrown upward at a(n) 37 angle to the horizontal. The acceleration of gravity is 9.8 m/s2 . To throw a(n) 57.8 m pass, what must be the initial speed of the ball? Answer in units of m/s
  55. Physics 1

    A football is thrown upward at an 48◦ angle to the horizontal. The acceleration of gravity is 9.8 m/s^2. To throw an 80.4 m pass, what must be the initial speed of the ball? Answer in units of m/s.
  56. Chemistry Numerical

    The half life period of a radioactive element is 27.96 days. Calculate the time taken by a given sample to reduce to 1/8th of its initial activity
  57. math

    a particle with initial velocity of 200m/s travels 1500m with uniform retardation 10m/s2.what is the time reqd? explain reason for two answer
  58. Physics

    If the force of friction is constant, prove that the stopping distance of a car on a level road varies directly with the square of the initial speed.
  59. English

    Thank you for your suggestions. Here is part of the exercise. 1) I b.. the newspaper every day. 2) Can you p... me the salt, please? 3) He knows all the a...... (Instructions: fill in the blanks with a suitable word. The initial is already given. (Does it
  60. physics

    A 0.5 kg block is sliding along a table top with an initial velocity of 0.2 m/s. It slides to rest in a distance of 70 cm. Find the frictional force that is slowing its motion.
  61. physics

    a 1240 kg automobile stops in a distance of 41m. if initial velocity was 22.5m/s, what force did the road exert on the car to stop it? Answer pls... Thank You
  62. Physics 1

    A rock is thrown straight upward with an initial velocity of 9.6 m/s in a location where the acceleration due to gravity has a magnitude of 9.81 m/s2. To what height does it rise? Help meh please.
  63. Math

    An initial investment in an account in which interest is compounded repeatedly is $813. If the time doubles the amount in 9 1/4 years, what's the annual rate going to end up being?
  64. algebra

    Brandon hit a baseball upward with an initial speed of 120 feet per second. How much later did Ollie catch the ball? Use the formula h = -16t squared + vt.
  65. Physics

    Two 6.0 μF capacitors, two 2.2 kΩ resistors, and a 14.5 V source are connected in series. Starting from the uncharged state, how long does it take for the current to drop from its initial value to 1.40 mA
  66. Physics

    A ball thrown straight up at ground level passes a height of 115.7 m in 5.6 s. The acceleration of gravity is 9.8 m/s^2. What was its initial speed? Answer in units of m/s.
  67. chem 2

    For 520.0mL of a buffer solution that is 0.140M in HC2H3O2 and 0.125M in NaC2H3O2, calculate the initial pH and the final pH after adding 0.020mol of HCl
  68. physics

    A football is kicked with an initial speed of 18 m/s at an angle of 36 degrees above the horizontal. (a) What is the maximum height that it reaches? (b) At what time does it land? (c) How far horizontally does it travel?
  69. accounting 305

    You are reviewing the December 31, 2012 financial statements of Ellie's Antiques that is considering an initial public offering of its shares. The following items come to your attention
  70. Physics

    A basketball is thrown at 45° to the horizontal. The hoop is located 6.2 m away horizontally at a height of 1.1 m above the point of release. What is the required initial speed? I know that I need to use d = vit + (0.5)at^2, but I then get stuck. Thanks!
  71. science

    An outfielder throws a 1.88 kg baseball at a speed of 57 m/s and an initial angle of 10.2. What is the kinetic energy of the ball at the highest point of its motion? Answer in units of J
  72. Physics

    A stone is thrown from ground level at 84 m/s. It's speed when it reaches it's highest point is 50 m/s. Find the angle, above the horizontal, of the stones initial velocity.
  73. Physics

    An outfielder throws a 2.12 kg baseball at a speed of 114 m/s and an initial angle of 54.8 ◦ . What is the kinetic energy of the ball at the highest point of its motion?
  74. physics

    an arresting device on a carrier deck stops an airplane in 1.5s. the avg. acceleration was 49 m/s2. what was the stopping distance? what was the initial speed? so i think v2=0, t=1.5, a= 49, so i need d and v1. i got v1=73.5 m/sec and d= 55 m. i took
  75. Physics

    Find the maximum height and the time of flight of a body fired vertically up from the ground given that it loses 60 percent of its initial speed in rising 4.2m

    if by some suitable mechanism the falling body had been given an initial downward push instead of just being released, would the resulting value of (g) acceleration due to gravity have been different?why? tnx....please answer it...
  77. Finance

    an initial outlay of $10000 resulting in a free cash flow of $1993 at end of each year for the next 10 years. the internal rate of return?
  78. chemistry

    Find the initial concentration of the weak acid or base in an aqueous solution of pyridine (C5H5N) with a pH of 8.65. Kb = 1.80×10−9 . Answer in units of mol/L
  79. physics

    A body is projected at an angle of 30 degree with the horizontal at initial speed of 200m/s. In how many seconds will it reach the ground? How far from the point of projection will it strike?
  80. physics

    A baseball pitcher throws a pitch with an initial velocity of 39.9 m/s, directed horizontally. How far does the ball drop vertically by the time it crosses the plate 18.0 m away?
  81. chemistry

    Find the initial concentration of the weak acid or base in an aqueous solution of pyridine (C5H5N) with a pH of 8.65. Kb = 1.80×10e-9 . Answer in units of mol/L
  82. Physics

    A stone is thrown from the ground with initial velocity v0 directed at angle alpha with respect to the horizon. Find equations of its motion both in x and y directions.
  83. physics

    A missile is launched at an angle of 25 degrees to the ground. It hits a target at 301.5 meters from the point of launch. find the initial velocity
  84. geometry

    Using the following values, calculate the amount accumulated (future value): Initial Principal = $9000 Interest Rate = 8% Number of years = 9 Monthly Compounding
  85. physics

    with an initial speed of 260km/h a train takes 1.50 x 10^3 m to stop on a level track. assuming the 'deceleration' is constant. what is the time in seconds taken for stopping?
  86. physics

    A 0.13 kg ball of dough is thrown straight up into the air with an initial speed of 18 m/s. The acceleration of gravity is 9.81 m/s2 .What is its momentum halfway to its max- imum height on the way up?
  87. Math

    Write an equation with phase shift 0 to represent simple harmonic motion with initial position -1/2, amplitude 1/2, and period 4. I got d=(1/2) sin (pi/2) t + (1/2). Is this correct?
  88. physics..

    What is the maximum height achieved if a 0.800 kg mass is thrown straight upward with an initial speed of 40.0 m·s–1? Ignore the effect of air resistance.
  89. Chemistry

    What is the maximum height achieved if a 0.800 kg mass is thrown straight upward with an initial speed of 40.0 m·s–1? Ignore the effect of air resistance.
  90. physics

    a 1240 kg automobile stops in a distance of 41m. if initial velocity was 22.5m/s, what force did the road exert on the car to stop it? Answer pls... Thank You
  91. Math - Trig

    A projectile is fired with an initial velocity of 88 ft/sec at an angle of 35° to the horizontal. Neglecting air resistance, what is the time of impact? I just can't figure it out.
  92. physics

    12.5 kg wooden crate with an initial velocity of 2.5 m/s slides across a rough cement floor for 1.7 m before coming to rest. Calculate the coefficient of kinetic friction
  93. physics

    suppose the diver vaults off the springboard, leaving it with an initial speed of 3.50 m/s upward. use energy conservation to find his spped when he strikes the water.
  94. physics

    what was the initial velocity of a race car traveling down a long straight track if it accelerates at 5.79m/s^2 and ends up going 163km/h in a time of 3.60 seconds?
  95. Chem

    This is the problem: In a 1-L beaker, 203 ml of 0.307 M ammonium chromate was mixed with 137 ml of 0.269 M chromium (III) nitrite to produce ammonium nitrite and chromium (III) chromate. Write the balanced chemical reaction occuring here. If the percent
  96. physics

    Assuming that the equation Ephoton, final = Ephoton, initial/1 + Ephoton, initial/mec2 (1 − cos θ) can be approximately applied at all scattering angles θ, what is the minimum energy of a scattered X-ray photon if the incident X-ray energy
  97. Chem

    Consider 1.40 mol of carbon monoxide and 3.20 mol of chlorine sealed in a 8.00 L container at 476 oC. The equilibrium constant, Kc, is 2.50 (in M-1) for CO(g) + Cl2(g) ↔ COCl2(g) Calculate the equilibrium molar concentration of CO. So I tried this
  98. Chemistry

    The pesticide DDT (C14H9Cl5)... Express these concentrations in ppm and in milimoles per liter. Orchard - Sample size: 250.0mL Mass of DDT: 0.030 mg Residential - Sample size: 1.750 L Mass of DDT: 0.035 mg Residential After a Storm - Sample size: 50.0 mL
  99. Chemistry

    Assume that a reaction occurs in which unknown substances R and S react to form unknown substances T and U. From the information below, determine the mass of substance T that will be formed if 45.0 grams of substance R reacts with 23.0 grams of substance
  100. Chemistry

    I'm having a bit of trouble translating what I see when I perform the experiment into actual chemical reactions. In one experiment, Magnesium is placed in Hydrochloric acid, and a burning splint is extinguished. So I think that it is producing Magnesium