1. Chemistry

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

    asked by Leroy on November 20, 2014
  2. 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

    asked by Victor on April 23, 2016
  3. 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?

    asked by Victoria on December 8, 2012
  4. chemistry

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

    asked by kim on April 5, 2013
  5. Chemistry

    Find the equilibrium moles for the following reaction with initially 0.051 mol for Ethyl acetate, 0.260 mol for water and 0.03045 mol of acetic acid at equilibrium. I'm not sure how to get the ones at equilibrium for the left side or even how much you have

    asked by Robert on August 3, 2012
  6. algebra

    An object is released into the air at an initial height of 6 feet and an initial velocity of 30 feet per second. The object is caught at a height of 7 feet. Use the vertical motion model, h = -16t^2+vt+s, where h in the height, t is the time in motion, s

    asked by alice on April 28, 2010
  7. chemistry

    50.0 mL of a solution of HCl is combined with 100.0 mL of 1.15 M NaOH in a calorimeter. The reaction mixture is initially at 22.4°C and the final temperature after reaction is 31.2°C. What is the molarity of the HCl solution? You may assume that there is

    asked by Marcus on February 28, 2015
  8. CHEMISTRY> HELP QUICK! pls

    1. The rate of a chemical reaction may be defined as: a) The speed at which a molecule travels from point A to point B. b) The change in concentration of reactants or products per unit time. c) The change in concentration of reactant divided by change in

    asked by Lucinda on August 29, 2010
  9. Chemistry

    Which of the following is TRUE for a system that is in dynamic equilibrium? A) The forward reaction goes to 100% completion. B) The concentration of products is equal to the concentration of the reactants. C) The reaction rate of the forward reaction

    asked by Mimi on December 10, 2016
  10. Phyiscs - due at 11PM EST!!

    Two identical conducting spheres, fixed in place, attract each other with a force of 0.114 N when their center to center separation is 45.00 cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres have a net

    asked by Bill on April 13, 2011
  11. physics

    A car is traveling at a constant initial velocity of 100km/h on a level portion of road. It encounters a 6 percent incline (tan(theta)= 6/100) at point A and the car decelerates at a constant rate of gsin(theta). Find the speed of the car (a) 10 seconds

    asked by Jessi on October 4, 2009
  12. Physics

    An object with mass 0.250 kg is acted on by an elastic restoring force with force constant 10.8 N/m. The object is set into oscillation with an initial potential energy of 0.150 J and an initial kinetic energy of 6.00×10−2 J. What is the amplitude of

    asked by Jake on April 3, 2011
  13. oscillation

    An object with mass 0.250 kg is acted on by an elastic restoring force with force constant 10.8 N/m. The object is set into oscillation with an initial potential energy of 0.150 J and an initial kinetic energy of 6.00×10−2 J. What is the amplitude of

    asked by Tyler on April 15, 2010
  14. Physics

    A ball is thrown vertically upward with an initial speed of 11 m/s . Then, 0.67 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 25 m/s . How far above the release point will the ball and stone pass

    asked by Linda on October 1, 2014
  15. physics

    A ball is thrown vertically upward with an initial speed of 25 m/s. Then, 1.8 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 32.1 m/s . How far above the release point will the ball and stone pass

    asked by Mariana on February 9, 2016
  16. thermodynamic

    Calculate the work necessary to compress air in an isolated cylinder with initial and final volumes of 6.0 and 1.2 ft^3, respectively. The initial pressure and temperature are 30.0 psia and 50 degree F, respectively.

    asked by chris on January 16, 2011
  17. Chemistry

    Neutralization reaction HCL(aq) + NaOH(aq) -> NaCl(s) + H2O(l) Use your results to determine the netball change of the neutralization reaction, in kJ/mol of NaOH, Write the thermochemical equation for the neutralization reaction. I'm not sure how to even

    asked by Julie on March 9, 2015
  18. Chemistry

    Hello, I really don't understand how to find the grams of moles in some of these reactions. If someone could help I would appreciate it. 1) Balance the following chemical reaction and determine the number of moles of HI produced when 2.33 moles of H2(g)

    asked by Anonymous on February 19, 2017
  19. Chemistry

    I'm sorry But I'm still so badly stuck and I don't get it Initial mass of candle 40.3g Mass of tin calorimeter 41.1g Mass of half-filled calorimeter with water 220.4g Initial temp of water 18.8°C Final temp of water 26.6°C Final mass of candle 38.2g

    asked by Anonymous on September 10, 2017
  20. Physics/Math

    The Formula you use is the correct one. However, consider this. If the initial PE existed, wouldn't you have to add it to the initial KE then subtract the PE at some R from the center? We normally make ground zero PE level, but for this... Zero, a

    asked by bobpursley on March 12, 2007
  21. chemistry

    The G value for formation of gaseous water at 298 K and 1 atm is -278 kJ/mol. What is the nature of the spontaneity of formation of gaseous water at these conditions? A. The reaction is never spontaneous. B. The reaction is sometimes spontaneous. C. The

    asked by Morgan on November 26, 2014
  22. chemistry help!!! please!!! DrBob222 I need you!!

    The G value for formation of gaseous water at 298 K and 1 atm is -278 kJ/mol. What is the nature of the spontaneity of formation of gaseous water at these conditions? A. The reaction is sometimes spontaneous. B. The reaction is spontaneous. C. The reaction

    asked by emma on August 20, 2016
  23. College Chemistry

    Now the reaction (2NO+2H2==> 2H20+N2) is believed to take place in three steps, the first of which is the fast reversible dimerization of NO to form N2O2, and the last of which (again fast) is the reaction N20 + H2 --> N2 + H2O. So, what is the slow

    asked by Crystal on April 18, 2012
  24. reversible reaction

    A+B C+D You mix some of A and B in a closed container and the reaction begins. As time passes, what happens to the amounts of A & B? As time goes on, what will happen to the rate at which A & B turn into C + D? Was there any C & D present when the reaction

    asked by abby on April 6, 2007
  25. Chemistry

    Half-life N2O5 dissolved in CCl4 decomposes to give N2O4 and O2. The reaction is first order with a half-life of 1234 seconds. How long will it take, in seconds, for the concentration of N2O5 to fall to 1.1% of its initial value?

    asked by Paul on December 1, 2012
  26. Chemistry Equilibrium Constant

    The initial pressures for I2 (g), H2(g), and HI(g) were Pi2 = 0.100 atm, Ph2 = 0.200 atm, and Phi = 0 atm, respectively. After the system came to equilibrium, the pressure of I2 (g) became very low, PI2 = 1.00 x 10^-5 atm. Calculate the equilibrium

    asked by Raskin on March 19, 2012
  27. Chemistry

    At 1200 K, the approximate temperature of vehicle exhaust gases, Kp for the reaction 2CO2(g)⇄2CO(g) + O2(g) is about 1*E-13. Assuming that the exhaust gas (total pressure 1 bar) contains 0.2% CO, 12% CO2 and 3% O2 by volume, is the system at equilibrium

    asked by Helen on August 16, 2008
  28. Chemistry

    A proposed mechanism for a reaction is: (i) A + B2 = AB2 Ea1 = 12 kJ/mol ƒ´H1 = 3 kJ/mol (ii) AB2 + C2 = ABC + BC Ea2 = 30 kJ/mol ƒ´H2 = 5.2 kJ/mol (iii) ABC + B2 = AB2 + BC Ea3 = 10 kJ/mol ƒ´H3 = -7.8 kJ/mol a) Which is the rate determining step?

    asked by Sarah on September 21, 2014
  29. Chem

    Carbonyl fluoride, COF2, is an important intermediate for organic fluorine compounds. It can be prepared by the following reaction: CO2(g) + CF4(g) 2COF2(g) At 1000*C, K for this reaction is .50. What are the partial pressures of all the gases at

    asked by JP on April 15, 2007
  30. CHEMISTRY

    The initial concentration of PCl5 was 0.1983 M. It was allowed to decompose at some temperature until equilibrium had been attained (see reaction below). What must be the equilibrium concentration of PCl3? PCl5(g) ↔ PCl3(g) + Cl2(g) Kc = 0.0580 a. 0.1162

    asked by Chemistry on April 6, 2014
  31. Chemistry

    A quantity of 100 mL of .5M of HCl (aq) is mixed with 100 mL of .5M of NaOH (aq) in a constant pressure calorimeter. The initial temperature of the solutions is 22.30 C and the final temperature of the mixed solution is 25.00 C. What is "q" for solution

    asked by Dante on April 9, 2012
  32. Chemistry

    The equilibrium constant Kp for the reaction below at 700°C is 0.76 atm. CCl4(g) C(s) + 2 Cl2(g) Determine the initial pressure of carbon tetrachloride that will produce a total equilibrium pressure of 1.20 atm at 700°C

    asked by Elizabeth on February 21, 2012
  33. Chemistry

    The equilibrium constant Kp for the reaction below at 700°C is 0.76 atm. CCl4(g) --> C(s) + 2 Cl2(g) Determine the initial pressure of carbon tetrachloride that will produce a total equilibrium pressure of 1.20 atm at 700°C

    asked by Andre on February 21, 2012
  34. Math prep

    1). Using the function: y=y0,(.90)^t-1. In this equation y0 is the amount of initial dose and y is the amount of medication still available t hours after drug is administered. Suppose 20mg of the drug is administered. How long will it take for this initial

    asked by Britt on November 19, 2012
  35. CHEMISTRY

    Method for getting correct answer for this? Thank you! A mixture containing an initial concentration of 0.1877 M for H2 and 0.1432 M for Cl2 is allowed to come to equilibrium (see reaction below). What must be the equilibrium concentration of HCl? H2(g) +

    asked by Chemistry on April 6, 2014
  36. Chemistry

    Describe the apparent relationship between H30 and OH concentrations when an endpoint is reached in acid-base titration.

    asked by Artem on April 21, 2008
  37. Ap chemistry

    Calculate the concentrations of all ions present in the following solutions of strong electrolytes : 2.0 times 10-3 M AL2(SO4)3

    asked by Tiffany on October 25, 2016
  38. chemistry

    Indicate the approximate of pH of a buffer made from equal concentrations of each of these pairs C6H5C00H/C6H5C00 H3B03/H2B03

    asked by dude of pluto on October 9, 2011
  39. Chemistry

    Pb(NO3)2(aq) + NaSO4(aq) → PbSO4(s)+ 2NaNO3(aq) Identify the ions that are present in each solution, and calculate their concentrations.

    asked by Sam on May 16, 2012
  40. chemistry

    In clinical lab reports, some concentrations are given in mg/dL. Convert a Ca2+ concentration of 3.5 mg/dL to weight/volume percent.

    asked by Jen on March 28, 2010
  41. Chemisrty

    Assuming equal concentrations, rank these solutions by pH: hclo4 caoh2 NH3 koh hbro

    asked by Carlos on March 6, 2016
  42. chemistry

    A solution is prepared by adding 50 mL of .050 M HCL to 150 mL of .10 M HNO3. Calculate the concentrations. I know I need to find the [H+] and [OH-] but im not sure how.

    asked by Dannie on March 7, 2010
  43. Chemistry

    A 0.500L vessel initially contains 0.0125 mol of H2S2 . Find the equilibrium concentrations of H2 and S2. Kc = 1.67 x 10^-7 2 H2S 2 H2 + S2

    asked by Veronica on June 8, 2014
  44. CHM

    Calculate the percent ionization of hydrazoic acid (HN3) in solutions of each of the following concentrations A) 0.377 M B) 0.107 M C) 4.16*10^-2 M Ka= 1.9*10^-5

    asked by Jordan on October 8, 2012
  45. AP Chemistry

    100. mL of 0.020 M CaCl2(aq) is added to 200. mL of 0.20 M K2SO4(aq). Calculate the equilibrium concentrations of Ca^2+ (aq) and SO4^2-(aq)

    asked by Bob on April 22, 2010
  46. chemistry

    In comparing normal blood concentrations are the solution 0.01% (m/v) NaCl isotonic, hypertonic, or hypotonic and could you explain?

    asked by veronica, rena, joshua on August 9, 2013
  47. chemistry

    calculate Ke for the following (equilibrium concentrations given below substances) N2O4(g)+heat yields 2NO2(g) [.0325] [.022] Thank you!

    asked by mary on January 19, 2010
  48. chemistry

    In comparing normal blood concentrations are the solution 0.01% (m/v) NaCl isotonic, hypertonic, or hypotonic and could you explain?

    asked by veronica, rena, joshua on August 9, 2013
  49. chemistry

    Calculate Ke for the following (equilibrium concentrations given below substances) H2(g)+Br2(g) yields 2HBr(g) + heat[.513] [.62] [.346] Thank you!

    asked by mary on January 19, 2010
  50. Calculus

    A ball is thrown straight up from the top of a hill 30 feet high with an initial velocity of 72ft/sec. How high above level ground will the ball get? (Objects subjected to gravity adhere to s(t) = -16t^2 + v0t + so where s is the height of the object in

    asked by Help on January 5, 2016
  51. AP Chemistry

    Q - An electrochemical reaction occurs between an unknown element and zinc. The half-cell reaction for the zinc is: Zn(s) → Zn2+(aq) + 2e− The cell potential for the reaction is Eºcell = 1.83 V. Is the reaction spontaneous or nonspontaneous? Explain.

    asked by Ned on November 9, 2016
  52. Chemistry

    In the reaction between H2O2 and I-, 15 mL of 0.30M KI, 65. mL of 0.10M H2O2 and 19 mL of 0.020M Na2S2O3 were mixed in a flask containing starch and buffer and the total volume was made up to 500mL with distilled water. The solution turned blue (indicating

    asked by Nikita on March 22, 2011
  53. chemistry

    In the presence of a tungsten catalyst at high temperature, the decomposition of ammonia to nitrogen and hydrogen is a zero order process. If the rate constant at a particular temperature us 3.7x10^-6 mol. How long will it take for an ammonia concentration

    asked by court on March 26, 2012
  54. Chemistry

    The reaction of CH4 in 2CH4(g) ---->/

    asked by Student on February 29, 2016
  55. Physics 101

    Two ice skaters, each with a mass of 72.0 kg, are skating at 5.10 m/s when they collide and stick together. If the angle between their initial directions was 117°, determine the components of their combined velocity after the collision. (Let the initial

    asked by Lorelei on March 3, 2016
  56. Chemistry

    I need some help with writing reactions. I have the following to write out: a. the hydration of copper sulfate b. the reaction of liquid sulfuric acid to form aqueous sulfuric acid c. the reaction of calcium oxide w/ water to form calcium hydroxide For a,

    asked by Nikki on October 4, 2009
  57. Calculus

    In a certain chemical reaction, substance A combines with substance B to form substance 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

    asked by Anonymous on December 4, 2017
  58. Chemistry

    I'm doing a chemistry lab called colorimetric equilibrium study of a complex ion. But I just have one question which is how to obtain CS which is the total stoichiometric molarity of thiocynate ion and CF which is iron (III) iron. Fe+3 + SCN --> Fe(NCS)^+2

    asked by Katie on September 14, 2012
  59. Chemistry/Equilibrium calculations

    At 1200 K, the approximate temperature of vehicle exhaust gases, Kp for the reaction 2CO2(g)->

    asked by Mary on August 16, 2008
  60. Chemistry

    At 1200 K, the approximate temperature of vehicle exhaust gases, Kp for the reaction 2CO(g) + O2(g) is about 1*10E-13. Assuming that the exhaust gas (total pressure 1 bar) contains 0.2% CO, 12% CO2 and 3% O2 by volume, is the system at equilibrium with

    asked by Helen on August 16, 2008
  61. Physics

    A soccer ball is kicked with an initial horizonal velocity of 18 m/s and an initial vertical velocity of 18 m/s. 1) What is the initial speed of the ball? 2)What is the initial angle of the ball with respect to the ground? 3)What is the maximum height the

    asked by Aziz on September 29, 2011
  62. Chemistry

    Please show me how to work! Ethane, C2H6(g) can be made by reaction of hydrogen gas with acetylene, C2H2(g). the standard enthalpies of formation of ethane and acetylene are -84.68 and +226.73 kJ mol-1, respectively. what is the reaction enthalpy for the

    asked by Sam on October 21, 2012
  63. chemistry

    For the reaction CO2 + H2 CO + H20 + heat, indicate how the change in condition will shift the equilibrium (ie right or left) a. Removal of CO2 b. Addition of H2 molecules c. Increase volume of reaction vessel d. Addition of catalyst e. Refrigerate

    asked by K on March 25, 2013
  64. Chemistry

    In a laboratory, the following reaction is performed by combining 358 g of H2O and a sufficient amount of CaC2. The percent yield for this reaction is 94.5%. Calculate the actual yield of acetylene (C2H2) in grams from this reaction. CaC2 + 2H2O C2H2 +

    asked by Lori on May 1, 2016
  65. 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 double-displacement

    asked by Robb4301 on February 4, 2015
  66. chemistry

    The standard internal energy change for a reaction can be symbolized as ΔU°rxn or ΔE°rxn. For the following reaction equations, calculate the energy change of the reaction at 25 °C and 1.00 bar. Sn(s) + 2Cl2(g) --> SnCl4(l) ΔH°rxn = -511.3 kJ/mol

    asked by jake on February 28, 2016
  67. Chemistry

    I know nothing about chemistry, but am wondering if someone could help me with these. 1) Balance this redox reaction using the oxidation-number method. Zn + O2 + HCl ® ZnCl2 + H2O 2) Balance this redox reaction using the half-reaction method. (basic

    asked by Sara on October 14, 2010
  68. Chemistry

    Asprin C9H8O4 is made by the reaction of salicylic acid C7H6O3 and acetic anhydride C4H6O3. The other product in the reaction is acetic acid HC2H3O2. How many of each reactant should be used to produce 75.0g of asprin. Assume that the reaction gives a

    asked by Mookie on October 9, 2008
  69. Chemistry

    A gaseous reaction occurs at a constant pressure of 50.0 atm and releases 69.8 kJ of heat. Before the reaction, the volume of the system was 8.80 L . After the reaction, the volume of the system was 2.80 L . Calculate the total internal energy change,

    asked by Brittany on March 5, 2012
  70. chemplz

    At 462degrees, the reaction (1) heat + 2 NOCl(g) 2 NO(g) + Cl2(g) has an equilibrium constant, Keq = 8.0 x 10-2. a) What is Keq at 462degrees for the reaction 2 NO(g) + Cl2(g) 2 NOCl(g) 1/Keq may I ask how did you get this answer? Keq for the reverse

    asked by Tom on May 2, 2007
  71. Chemistry

    3.25g of zinc was added to 50cm^3 of a 4.0 molar dm^-3 HCl. When the reaction was completed the temperature rose by 28 degrees celcius. (a) Is the reaction exothermic or endothermic? (b)All the zinc dissolve in this reaction. How many moles of zinc

    asked by Jessica on March 25, 2014
  72. algebra

    Patty is only 7 years old, but she insists she can play basketball with a regulation-height hoop. She can throw the ball with an initial velocity of 11 feet per second. The equation for the height of the ball is y = −16t2 + vt + s where v is the initial

    asked by uriel on February 12, 2011
  73. algebra

    Patty is only 7 years old, but she insists she can play basketball with a regulation-height hoop. She can throw the ball with an initial velocity of 11 feet per second. The equation for the height of the ball is y = −16t2 + vt + s where v is the initial

    asked by uriel on February 12, 2011
  74. Chemistry

    I have this question in front of me concerning Methanol (CH3OH) & how geseous methanol is formed via the following thermochemical equation: CO(g)+2H2(g)¡êCH3OH(g)∆H=-90kJ . Now, it asks me (explanations should show a clear understanding of how Le

    asked by Travis on February 7, 2007
  75. chemistry

    In a certain chemical reaction 1.00 gram of product is produced in 15 minutes when the reaction is carried out at 20oC. Assuming that there is sufficient starting material available, how much product will be produced in the same length of time if the

    asked by chris on April 12, 2010
  76. chemistry

    In a certain chemical reaction 1.00 gram of product is produced in 15 minutes when the reaction is carried out at 20oC. Assuming that there is sufficient starting material available, how much product will be produced in the same length of time if the

    asked by chris on April 12, 2010
  77. chemistry

    A definite amount of nh4cl was boiled with 100ml of 0.8N naoh for complete reaction. After the reaction, the reaction mixture containing excess of naoh was neutralized with 12.5ml of 0.75N nh2s04. Calculate the amount of nh4cl taken. The answer 3.78g who

    asked by Fai on February 10, 2013
  78. Chemistry

    A 1.0-mL volume of 0.010 M H2SO3 is added to a mixture of 12 drops of 0.010 M HIO3, 8 drops of deionized water, and 1 drop of starch solution. a color change occured after 40 seconds. the rate of reaction is measured by the disappearance of HIO3. got the

    asked by Anonymous on February 22, 2013
  79. Chemistry

    I posted before about designing a procedure to determine two unknowns (1 solid, 1 solution). The possible solutions were: NaCl, CaCl2, CuSO4, NaOH,Ba(OH)2, HCl, HNO3, or H2O. The reagents given are: NaOH, HCl, AgNO3, Zn metal, Na2SO4, and H2O. The

    asked by Raj on November 11, 2007
  80. Chemistry

    Consider the following reaction: H2+I22HI A reaction mixture at equilibrium at 175 K contains P(H2)=0.958 atm, P(I2)=0.877 atm, and P(HI)=0.020 atm. A second reaction mixture, also at 175 K, contains P(H2)=P(I2)=0.616 atm, and P(HI)=0.106 atm. What will

    asked by Brooke on April 4, 2011
  81. Chem -Bob Pursley Please Help!

    Consider the following reaction: 2 HI (g) → H2 (g) + I2 (g) Assume that an experiment is carried out in which the starting concentration of HI (g) is 0.100 mol/L. No products are present at the beginning of the reaction. When equilibrium is established,

    asked by Michael on March 10, 2018
  82. Chemistry 2

    An industrial chemical reaction has a rate law: rate = k [C]. The activation energy for the reaction is 3.0000 x 10^4 J/mol and A = 2.000 x 10^-3. What must be the reaction temperature if a rate of 1.000 x 10^-9 M/s is required and [C] must be kept at

    asked by Jessica on March 12, 2012
  83. Physics

    What is the kinetic energy of an ideal projectile of mass 19.4 kg at the apex (highest point) of its trajectory, if it was launched with an initial speed of 29.2 m/s and at an initial angle of 46.9° with respect to the horizontal?

    asked by Anonymous on October 22, 2014
  84. physics

    find the solution of the wave equation for a vibrating string of length (l)=10units with ends fixed .it is given that c^2=1,initial velocity is zero and initial deflection is u(x,o)=k(sinx-sin2x)

    asked by ashely on February 11, 2012
  85. math

    how do I solve this problem 2x/2=(6-3y)/2? 2x/2=(6-3y)/2? I solved it for you in my initial answer. The 2 in the numerator cancels with the 2 in the denominator on th left side and x = (6-3y)/2 which is the solution of the initial equation you had for x in

    asked by cheryl on March 18, 2007
  86. Chemistry(Please check, thank you!!)

    For my rate of reaction experiment I have to answer the question "why did we ask you to measure the room termperature and temperature of reaction solutions". For the experiment we used 5 flasks and we put one of them in an ice bath at 6-10 degrees C. My

    asked by Hannah on February 28, 2012
  87. mathematical physics

    Solve the initial initial value problem d^2x/dt^2+2DX/dt-3x =0, x(2π) = 0, x(2π) = 13

    asked by gourav on March 27, 2015
  88. Chemistry

    for the reaction 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) if H = -950kJmol-1, does that mean it's an exothermic reaction? Ooops pressed Post too quickly. Yes it is exothermic. Delta H is negative so heat is lost from the system. If delta H is positive a reaction

    asked by Fiona on April 30, 2007
  89. Chem II

    The equilibrium constant of a reaction is 12.6. If the rate constant of the reverse reaction is 5.1 x 10 -2 the rate constant for the forward reaction is _____ 0.32 0.16 0.64 0.08 I don't even know where to start on this question. Any direction will help

    asked by Ken on June 17, 2008
  90. Life Science

    I tried looking and can't find or understand where the following answer are. Please help me, I feel like I'm going crazy. I’m not sure about the answers I wrote but if someone could correct them and help me out with the ones I didn’t get.

    asked by Bretagne on January 27, 2008
  91. Chemistry

    I have a reaction here: 2Na3PO4.12H2O + 3BaCl.2H2O --> Ba3(PO4)2 + 6NaCl + 30H2O and a question: 0.349g of BaCl2.2H2O and 0.624g of Na3PO4.12H2O are dissolved in 500mL of water to form a solution - how many grams of the excess reactant remain after the

    asked by Lacey on September 25, 2007
  92. chemistry

    an ezyme -catalysed reaction was carried out in a solution buffered with 0.05 M phosphate ph 7.2 . As a result of the reaction ,0.06M of acid was formed. (phosphoric acid has three pka values. The one required for this calculation is pka2=7.2). 1) what was

    asked by josh on January 13, 2016
  93. Chemistry

    The standard internal energy change for a reaction can be symbolized as ΔU°rxn or ΔE°rxn. For the following reaction equations, calculate the energy change of the reaction at 25 °C and 1.00 bar. Sn(s) + 2Cl2(g) --> SnCl4(l) ΔH°rxn = -511.3 kJ/mol

    asked by Anonymous on September 22, 2013
  94. statistics

    1. A professor measured the time (in seconds) required to catch a falling meter stick for 19 randomly selected students’ dominant and non-dominant hand. The professor claims that the reaction time in an individual’s dominant hand is less than the

    asked by arshi on November 24, 2013
  95. math

    A professor measured the time (in seconds) required to catch a falling meter stick for 19 randomly selected students’ dominant and non-dominant hand. The professor claims that the reaction time in an individual’s dominant hand is less than the reaction

    asked by anonymous on December 3, 2013
  96. physics

    Energy is released during a nuclear reaction due to a conversion between mass and energy. Mass is not conserved. The initial and final amounts are different. If a total of 4.6 g of mass were “missing”, how much energy is released? The speed of light

    asked by Anonymous on May 29, 2013
  97. chemistry

    Determine Kc at 298 K for the reaction 2 CH4(g) reverse reaction arrow C2H2(g) + 3 H2(g), given the following data at 298 K. (Hint: How are Kc and Kp for the reaction related?) CH4(g) + H2O(g) reverse reaction arrow CO(g) + 3 H2(g) Kp = 1.2 multiplied by

    asked by Jenny on March 24, 2010
  98. chemistry

    i already posted this question, but im still confused on it. Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) -> 2NO2 (g) 2NO2 (g) Initial conc. 0.400 mol 0 mole (no reaction yet) Change -0.3945 mol + 2 x 0.3945

    asked by Jane on October 26, 2010
  99. Biology

    To take the energy from an exergonic reaction and use it to power an endergonic reaction, a cell can: create the energy for the endergonic reaction to occur. Why is this false? I thought a exergonic reaction create energy for the endergonic reaction to

    asked by Anon on March 18, 2013
  100. chemistry

    calculate the half-life of a first- order reaction if the concentration of the reactant is 0.0396 M at 12 seconds after the reaction starts and is 0.00579 M at 47 after the reaction starts. How long does it take for the reactant concentration to decrease

    asked by saud on November 19, 2011