1. Chemistry

    The half-life of the following first order reaction is 231 seconds. What percent of the original concentration of nitrite ion remains after 10.0 minutes? NH4+ + NO2- --> N2 + 2H2O

    asked by Ceamus Angelina on July 1, 2018
  2. Physics!

    Consider someone in a rotating space habitat. The outward force felt by the person A.has no reaction counterpart B.is an interaction with Earth C.is a form of gravity D.is real in the traditional sense

    asked by Anonymous on March 19, 2014
  3. Chemistry-Stoichiometry

    A 1.146g mixture of the solid salts NaS)4 and PB(NO3)2 forms an aqueous solution with the precipitation of PbSO4. How would I write the molecular form of the equation for the reaction?

    asked by Edward on March 1, 2012
  4. Chemistry

    2CO(g) + O2(g) 2CO2(g) Go = -511.6 kJ and So = -173.1 J/K at 314 K and 1 atm. The maximum amount of work that could be done by this reaction when 2.43 moles of CO(g) react at standard conditions at this temperature is__________ kJ. how?!

    asked by Bryan on April 26, 2012
  5. chemistry

    Need to find info about chemical reaction of lemon juice and baking soda. Doing experiment where gas produced will inflate balloon hopefully. Will outcome be a lot different than if I had used vinegar?

    asked by Kay on December 7, 2012
  6. Chemistry

    Please check this over and see of they are right...if they are not can you please tell the the right answer and explain how you got it. I think I am getting myself confused. Thank you. Write the neutralization reaction for each of the following. Balance

    asked by Brittney on August 25, 2010
  7. Chemistry

    Do you know how to set up the ICE? That's what you need to do. If you know but are confused, tell us what you don't understand about it. At 55 degrees celcius, the K for the reaction: 2NO2 (g) N2O4(g) is 1.15 Calculate the concentration of N2)4(g) present

    asked by DrBob222 on May 15, 2007
  8. chem

    Based on the ratio of mean moles of O2/mol KClO3 what is the chemical equation for the reaction that occurred? Why? Is this conclusion in accord with the mass of the solid product that you obtained? Explain

    asked by rachel on April 7, 2018
  9. Chemistry

    Suppose 0.30 g of ethane is mixed with 0.47 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.

    asked by monica on December 6, 2011
  10. chemistry

    the standard free energies of formation of SO2(g) and SO3(g) are -300.4 and -370.4kJ mol-1 respectively. Calculate the value of the equilibrium constant at 25'C for the reaction 2SO2(g)+O2(g)==>2SO3(g)

    asked by harry on February 12, 2013
  11. Chemistry(please check my answer)

    Among the following, which is an oxidation-reduction reaction? A. Na2S + CaCO3 → CaS + Na2CO3 B. 2HNO3 + Mg(OH)2 → Mg(NO3)2 + 2H2O C. H2 + F2 → 2HF**** D. 3Ba(OH)2 + 2H3PO4 → Ba3(PO4)2 + 6H2O

    asked by Cherry on September 1, 2016
  12. Chem--PLEASE HELP 911

    Balance the following redox reaction and identify the oxidizing and reducing agents A- Fe2+(aq) + Cr2072-(aq) -->Fe3+(aq) + Cr3+(aq) (acidic) B- N2H4(g) + ClO3-(aq) -->NO2(g) + Cl- (basic)

    asked by JO on April 25, 2013
  13. Chemistry

    Calculate the number of mL of hydrogen gas at 27 degrees Celsius and 640 Torr produced by the reaction of 0.520 grams of magnesium with excess hydrochloric acid.

    asked by Noah on February 5, 2012
  14. chemistry

    Write the reaction equation for Isopropylbenzene producing Benzene P.S I don't mean to be overburdening you with the same kinds of questions its just that there is a quiz on this stuff on Monday and I want to be FULLY prepared LOL

    asked by Priya on May 2, 2008
  15. Chemistry

    Balance the following redox reaction and identify the oxidizing and reducing agents A- Fe2+(aq) + Cr2072-(aq) -->Fe3+(aq) + Cr3+(aq) (acidic) B- N2H4(g) + ClO3-(aq) -->NO2(g) + Cl- (basic)

    asked by jo on April 25, 2013
  16. Chemistry

    The activation energy for a certain reaction is 113 KJ/mol. By what factor (how many times) will the rate constant increase when the temperature is raised form 310K to 325K? Answer: 7.6

    asked by Anonymous on February 7, 2013
  17. Chemistry

    Why does the reaction of 2-bromo-2-methylbutane and ethanolic solution of silver nitrate interfered by the presence of water in the sodium iodide in acetone reagent? (Substitution chemistry) Thanks for any help!!

    asked by Andrew on November 16, 2008
  18. Chemistry

    what is the balanced net ionic equation for the reaction of ascorbic acid with triiodide ion C6H8O6 ==> C6H6O6+ 2H^+ + 2e 2e + I3^- ==> 3I^- ==================== These are to two half equations. Add them and cancel the electrons.

    asked by mary on October 8, 2006
  19. Chemistry

    Given info: Time(s). (ClO) mol/L 0.0. 0.012 4.0. 0.008 8.0. 0.005 12.0. 0.0035 16.0. 0.0025 20.0. 0.002 24.0. 0.0018 28.0. 0.0017 Calculate the average rate of the overall reaction

    asked by Rose on April 24, 2016
  20. Health And Physical Education

    Identify a common defense mechanism that protects you from an uncomfortable? A.reaction formation B.abstinence C.mature behaviors D.acceptance I would like to know if anyone knew the answer and if so can you please tell me my parents are getting on to me

    asked by Margaret on October 7, 2016
  21. Science

    When sodiun is placed in water,it reacts violent to produce hydrogen gas and form sodium hydroxide solution. write a balanced chemical equation for this reaction

    asked by Boren on February 10, 2017
  22. organic chem

    I prepared triphenylmethanol by a grignard reaction. At the end you add petroleum ether to the mixture and heat it up. It stayed a liquid and got dark and oily but never solidified. What went wrong?

    asked by emily on March 25, 2013
  23. Chemistry

    Zinc reacts with hydrochloric acid according to the reaction equation: Zn(s)+2HCl(aq)->ZnCl2(aq)+H2(g) How many milliliters of 4.50M HCl1(aq) are required to react with 8.25g of an ore containing 30.0% Zn(s) by mass?

    asked by Anna on October 7, 2012
  24. Chemistry 11

    What is the concentration of the solution formed when zinc metal is reacted with 950.0 cm3 of 1.25 M hydrochloric acid? What is the volume of hydrogen gas (at stp) that is evolved in the same reaction?

    asked by Dawn on July 19, 2018
  25. Chemistry

    Calculate the volume of 1.78M sulfuric acid that would be needed to neutralize 62.4 mL of a 2.09 M aqueous ammonia solution. The equation for the reaction is H2SO4(aq) + 2 NH3(aq) ---> 2 NH4(aq)+ SO4 ^-2 (aq)

    asked by Brea on April 16, 2012
  26. Chemistry - Significant Figures

    Suppose it takes 35 min for 2.4 g of sugar to completely react with another reagent we added to the flask. What would the reaction rate be? Calculate to the correct number of significant figures.

    asked by Jamie on May 18, 2017
  27. Chemistry

    3C3H8 + 20H2CrO4-> 9CO2 + 10Cr2O3 + 32H2O Suppose you want to make 1.50 g of chromium (III) oxide, how many ml of 6.25M chromic acid will you need to use if the percent yield of the reaction is 68.6%?

    asked by Michelle on November 27, 2012
  28. cheistry

    Write a net ionic equation for the overall reaction that occurs when aqueous solutions of hydrosulfuric acid and potassium hydroxide are combined. Assume excess base.

    asked by savannah on November 17, 2011
  29. Chemistry

    Sorry I accidently hit enter and it posted my question before I was finished... What are the major organic products of this reaction: CH3CH2CH2COCH2CH3 (an O is double bonded to the C before the O) + H2O --> (acid is above the arrow)

    asked by Bobby on March 21, 2010
  30. chemistry

    Explain why methanol spontaneously evaporates in open air at 25.0 . I know that a negative delta G means a spontanious reaction, but I don't think this is an adequate response to this question. I need a little more clarity about this. thanks

    asked by redgy on April 16, 2011
  31. Chemistry

    1. what reaction take place when water is passed through anion exchange resin ? 2. how much na2co3 or salked lime should be added to completely 300cm^3 of 2percent cacl2 solution ?

    asked by Saszuuu on October 12, 2015
  32. Chemistry

    Which of the following is best described as an acid-base reaction? 1. 2HgO -> 2 Hg + O2 2. NH3 + H2O -> NH+4 + OH− 3. KCl + NH4NO3 -> KNO3 + NH4Cl 4. Ca + 2H2O -> Ca(OH)2 + H2 5. NaCl + AgNO3 ->NaNO3 + AgCl How do u tell if it is a salt or not?

    asked by Elva on October 16, 2010
  33. chem- electrochem-HELP

    Determine the equilibrium constant, Keq, for the reaction 5.3 10–19 18.30 1.7 1054 1.9 1018 5.7 10–55 i have tried this but get the wrong answer. i have the half-rxn and fugured out E=0.536. then used eq dG=-nFE, followed by dG=-RTInK. PLS HELP

    asked by lucylu on September 18, 2010
  34. Chemistry

    Consider the reaction below : P4(s) + 5O2(g) P4O10(s) How many grams of phosphorus react with 1.195 x 102 L of oxygen (O2) at STP (standard temperature and pressure) to form tetraphosphorus decaoxide?

    asked by Rayan on February 15, 2018
  35. college chemistry

    calculate the equilibrium constant for the following reaction at 298k given that DeltaGrxn=2.8kj/mol N2O4-2NO2 I thought to get K you use the expression K=e^(-deltaG/(RT)) but I cant get the same answer my professor put down which is 3.1

    asked by Jeremy on April 6, 2016
  36. Chemistry

    Using a closed system experiment will a leak during gas evolving reaction overstate or understate the amount of sodium bicarbonate in an alka seltzer cold tablet?

    asked by Anonymous on September 7, 2016
  37. college chemistry

    Use standard enthalpies of formation to determine ƒ¢Horxn for: 2NH3(g) + 3O2(g) + 2CH4(g) ¨ 2HCN(g) + 6H2O(g) in kilojoules. Find the change in internal energy for this reaction in kJ

    asked by jake on October 18, 2010
  38. Chemistry

    Okay, so i've got 8 reactions i am supposed to balance "according to the half-reaction method". Only problem is, i was gone for the lesson, and my borrowed notes look like an entirely different language! So if you could please show me the steps and explain

    asked by Nessy on May 21, 2010
  39. chemistry

    1) A Galvanic cell runs on the following reaction: Co (s) + Cu2+ (aq) → Co2+ (aq) + Cu (s) Draw a diagram for this Galvanic cell, labeling the electron flow, the anode and cathode, and the positive and negative sides of the Galvanic cell. 2) A Galvanic

    asked by Natalie on January 25, 2017
  40. chemistry

    Condition Pressure Volume Temperature Comment initial 1.0 atm 22.4 L 273 K 1 mole of N2 gas fills the tank. final 3.0 atm 22.4 L 273 K 2 moles of O2 gas have been added to the 1 mole of N2 gas in the tank. Key Questions 7. What was the initial pressure

    asked by alex on March 21, 2013
  41. chemistry

    The balanced equation doesnt seem to help because the thiosulfate is not in the equation, I think it is preventing the reaction from going backwards. THe equation is: 2iodide ion + hydrogen peroxide + 2 H3O --> elemental iodide + 4 H2O within the reaction

    asked by jacob on February 5, 2007
  42. physics

    A bumper car with mass m1 = 100 kg is moving to the right with a velocity of v1 = 4.6 m/s. A second bumper car with mass m2 = 86 kg is moving to the left with a velocity of v2 = -3.8 m/s. The two cars have an elastic collision. Assume the surface is

    asked by stewart on October 14, 2014
  43. physics.

    A 20.0 kg cannon ball is fired from a cannnon with muzzle speed of 1000 m/s at an angle of 37.0 with the horizontal. A second ball is fired at an angle of 90.0. Use the conservation of energy principle to find a] the maximum height reached by each ball and

    asked by Jean on March 15, 2007
  44. physics

    A brick is thrown upward from the top of a building at an angle of 25° to the horizontal and with an initial speed of 17 m/s. If the brick is in flight for 2.5 s, how tall is the building?

    asked by tiffany on September 20, 2010
  45. Chemistry

    Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10-2 hr-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

    asked by Ericka on December 10, 2009
  46. Physics

    A quantity of monatomic ideal gas expands adiabatically from a volume of 2.0 liters to 6.0 liters. If the initial pressure is P0, what is the final pressure?

    asked by Alex on February 12, 2013
  47. Chemistry

    Radium-223 has a half-life of 11.4 days.Approximately how long would it take for the activity of a sample of Radium-223 to decrease to 1.00% of its initial value?

    asked by Michelle on March 1, 2013
  48. science

    A balloon with an initial volume of 2.8L at a temperature of 296K is warmed to 375K . What is its volume at the final temperature? (Assume constant pressure.)

    asked by michelle on October 22, 2012
  49. Physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 12 m/s. If the brick is in flight for 3.5 s, how tall is the building?

    asked by Court on September 11, 2011
  50. physics

    A brick is thrown upward from the top of a building at an angle of 15° to the horizontal and with an initial speed of 16 m/s. If the brick is in flight for 2.8 s, how tall is the building?

    asked by Claudia on September 27, 2010
  51. Physics, newtons laws

    A bullet is fired with a certain velocity at an angle above the horizontal at a location where g= 10.0 m/s^2. The initial x any components of its velocity are 86.6 m/s and 50 m/s respectively. How long does it take before the bullet hits the ground?

    asked by Naf on October 29, 2012
  52. physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 14 m/s. If the brick is in flight for 3s, how tall is the building?

    asked by TNT on February 16, 2018
  53. Math, Science

    A woman throws a 0.25 kg ball straight up in the air with a initial speed of 15 meters per second. how far above the woman will the ball go before it starts coming back down?

    asked by Wyatt Bendickson on April 2, 2015
  54. physics

    A brick is thrown upward from the top of a building at an angle of 40° to the horizontal and with an initial speed of 12 m/s. If the brick is in flight for 2.5 s, how tall is the building?

    asked by Anonymous on September 25, 2010
  55. Chemistry

    An aqueous solution of an unknown, monobasic weak base has an initial molarity of .176 M and a final[OH-] of .0000158 M. What is the Kb of the unknown base?

    asked by Natalie on December 8, 2010
  56. Physics

    What happens when an electron travels through an electric field? Will its speed remain constant or will it accelerate? The initial velocity is in the same direction as the electric field.

    asked by Ichi on January 26, 2019
  57. Physics

    An object is thrown upwards at an initial speed of 19.6m/s from a height of 55m. How long will it take for the object to reach the ground.(from the time it was thrown)

    asked by Derp on August 22, 2012
  58. physics

    A boy moves 400m towards north 300m towards west and again 400m towards south calculate displacement of the boy from initial position

    asked by rom on June 25, 2016
  59. physics

    a ball is thrown vertically into the air because of air resistance its speed when it returns to its staring level compared to it initial speed is what?

    asked by Anonymous on February 6, 2011
  60. physics

    The ball is thrown with an initial speed of 3.7 m/s at an angle of 15.4° below the horizontal. It is released 0.83 m above the floor. What horizontal distance does the ball cover before bouncing?

    asked by !!!! on September 12, 2011
  61. Physics

    A proton collides head on with a helium atom at rest. Their combined velocity after the collision is 8 x 10^5 ms^-1. Calculate the initial velocity of the proton. *** HELP PO PLEASE!!

    asked by Carolyn Bautista on January 31, 2013
  62. physics

    two stones with initial speeds of 13 m/s and are thrown at an angle 30 degrees, one below the horizontal and one above the horizontal. What is the distance between the points where the stones strike the ground?

    asked by James on September 29, 2012
  63. Solution Stoichiometry

    If 75.0 mL of an AgNO3 solution reacts with enough Cu to produce .25g Ag by single displacement, what is the molarity of the initial AgNO3 solution if Cu(NO3)2 is the other product?

    asked by Anonymous on March 29, 2009
  64. physics

    A metal sphere is launched with an initial velocity of 1.5 m/s as it leaves the ramp. The end of the ramp is 1.2 m above the floor. Calculate the range of the sphere.

    asked by Christian on October 13, 2014
  65. physics

    a ball is thrown upward with an initial velocity. What is it's velocity to halfway to its highest point? the answer is the square root of 2, but how do u get that answer?

    asked by Anonymous on October 19, 2008
  66. physics

    two stones with initial speeds of 13 m/s and are thrown at an angle 30 degrees, one below the horizontal and one above the horizontal. What is the distance between the points where the stones strike the ground?

    asked by James on September 29, 2012
  67. physics

    two stones with initial speeds of 13 m/s and are thrown at an angle 30 degrees, one below the horizontal and one above the horizontal. What is the distance between the points where the stones strike the ground?

    asked by James on September 29, 2012
  68. physics

    a stone is thrown vertically upward with an initial velocity u from the top of tower, reaches the ground with a velocity 3u. what is the height of tower?

    asked by pavatharani on July 13, 2011
  69. physics

    A 240 g ice cube at -10 C is placed in an aluminum cup whose initial temperature is 70 C. The system comes to an equilibrium temperature of 20 C. What is the mass of the cup?(answer in kg)

    asked by ana on December 2, 2009
  70. MATH

    a drug has a half life of 5 hours. write the exponential function that gives the concentration of the drug over time assuming an initial concentration of 2 mg/ml

    asked by Matt on September 21, 2016
  71. physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 15 m/s. If the brick is in flight for 2.7 s, how tall is the building?

    asked by lisa on February 5, 2016
  72. physics

    The initial velocity of a 1.55 kg block sliding down a frictionless inclined plane is found to be 1.27 m/s. Then 1.07 s later, it has a velocity of 5.37 m/s. What is the angle of the plane with respect to the horizontal?

    asked by sam on February 12, 2014
  73. Physics

    A ball is thrown straight up, when it reaches the maximum height x, a second identical ball is thrown up with the same initial velocity as the first one. Where will these balls meet.

    asked by John on September 11, 2013
  74. Physics

    A brick is thrown upward from the top of a building at an angle of 25° to the horizontal and with an initial speed of 17 m/s. If the brick is in flight for 3.3 s, how tall is the building? m

    asked by Crown on September 12, 2012
  75. Physics

    A proton collides head on with a helium atom at rest. Their combined velocity after the collision is 8 x 10^5 ms^-1. Calculate the initial velocity of the proton. *** HELP PO PLEASE!!

    asked by Carolyn Bautista on January 31, 2013
  76. Physics

    A proton collides head on with a helium atom at rest. Their combined velocity after the collision is 8 x 10^5 ms^-1. Calculate the initial velocity of the proton. *** HELP PO PLEASE!!

    asked by Carolyn Bautista on January 31, 2013
  77. physics please help

    A soccer ball is kicked from the top of a 256 -foot building with an initial velocity of 6 ft/s. How far from the base of the building will the ball land?

    asked by carissa on October 19, 2008
  78. physics

    A water balloon is launched at a building 24m away with an initial velocity of 18 m/s at an angle of 50° above the horizontal. At what height will the balloon strike the building?

    asked by James on October 13, 2014
  79. Physics

    A ball rolls off the edge of a table that is 1.03 m high, and it strikes the floor at a point 1.40 m from the base of the the table. What is the initial speed in m/s of the ball?

    asked by Asia on November 13, 2012
  80. Math

    An object is launched upward from the ground with an initial vertical velocity of 40 feet per second. After how many seconds does the object reach a height of 25 feet?

    asked by Amy on April 18, 2013
  81. Physics

    A ball is thrown straight up, when it reaches the maximum height x, a second identical ball is thrown up with the same initial velocity as the first one. Where will these balls meet.

    asked by John on September 11, 2013
  82. Physics

    A body is moving with uniform acceleration covers 100m in the first 10s and 150m in the next 10s. Find the initial velocity of the body.

    asked by BHAVIN on May 18, 2017
  83. phy

    A baseball is thrown horizontally from the top of a cliff 50 meters up. The initial velocity of the ball is 10 m/s. How far from the base of the cliff will the ball land?

    asked by Anonymous on March 5, 2014
  84. Biology

    The half -life of carbon-14 is 5,730 years.how much of an initial amount of this substance would remain after 17,190 years(3 Half-lifes

    asked by Eileen on November 23, 2010
  85. Physics

    A 5 gm bulet initial velocity is 300ms-1 and after penetrating a 5cm plank then the bulet stopped . So how much time is needed to penetrate the plank..?

    asked by Alvi on November 23, 2016
  86. physics

    A brick is thrown upward from the top of a building at an angle of 40° to the horizontal and with an initial speed of 16 m/s. If the brick is in flight for 3.4 s, how tall is the building?

    asked by kaf on January 29, 2012
  87. Chemistry

    The half life of a radioactive material is 120 months. How much of this material will be left after 350 months if the initial concentration is 2.40M?

    asked by Kay on May 1, 2017
  88. physics

    A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.30 and the push imparts an initial speed of 4.0 m/s?

    asked by KatieC on October 18, 2010
  89. high school physics

    a ball is thrown hirizontally from the roof of a building 45.0 meters tall and lands 24.0 meters from the base. what was the ball's initial speed

    asked by Michael on October 20, 2008
  90. Physics

    A golfer hits a golf ball at an angle of 35° above horizontal. If the initial velocity is 55 m/s, how long does the ball soar before it hits the ground?

    asked by Elaina on December 1, 2010
  91. Physics

    Two identical objects of the same mass and at the same initial temperature cool off. If object A cools off faster than object B, what can you say about the specific heats of the two objects?

    asked by Anonymous on January 14, 2015
  92. PHYSICS

    Charlie now moved onto the next hole where he hit the ball with an initial speed of 30 m s-1 and at an angle of 60 degrees. This time the ball lands with a speed of 17.3 m s-1. Use g = 9.8 m s-2.

    asked by PHYSICS on December 15, 2016
  93. Physics

    A cork shoots out of a champagne bottle at an angle of 39.0 degrees above the horizontal. If the cork travels a horizontal distance of 1.10 m in 1.40 s, what was its initial speed?

    asked by Abby on February 16, 2010
  94. physical science

    a motorcycle has a mass of 2.50*1000 kg. a constant force is exerted on it for 60.0 s. The motorcycle's initial velocity is 6.00 m/s and its final velocity 28.0 m/s. What is its change in momentum?

    asked by Anonymous on September 26, 2011
  95. physics

    Ball A, moving with an initial speed of 3 m/s, has a head-on collision with another ball B at rest, which is twice as massive as A . What are the final velocities of A and B if the collision is elastic?

    asked by jay on December 2, 2012
  96. Physics

    a body moving with uniform acceleration travels 84m in First6s and 180m in next 5s . Find the initial velocity and acceleration of body

    asked by Anonymous on May 1, 2017
  97. physics

    You throw a ball vertically from an apartment balcony to the ground 14.2 m below. Find the ball's initial velocity if it hits the ground 1.08 s after you release it.

    asked by squad on September 30, 2013
  98. physics

    A marble is thrown vertically downward at an initial velocity 200cm/s hits the floor in 2.5 seconds ,At what height is the marble thrown?

    asked by happy on July 15, 2015
  99. chem

    What is the final temperature (degrees celcius) of 1.36g of water with an initial temperature of 23.0degrees celcius after 6.420J of heat is added to it?

    asked by Chironjit on November 19, 2012
  100. Calculus Physics

    A particle is subject to a time-dependent force: F(t)=5t√. If the particle's mass is 7 kg, what will its velocity be at t=6.7 seconds, assuming its initial velocity at t=0 is equal to 0.

    asked by danny on February 19, 2015