1. chemistry

    The normality of Hv2SOv4 is given as 0.20 N for a reaction in which the Hv2SOv4 furnishes two hydrogen ions. What is the molarity of the Hv2SOv4? A. 0.40 M B. 0.30 M C. 0.20 M D. 0.10 M
  2. Science

    Write a mechanism for the Claisen reaction of ethyl ethanoate (ethyl acetate) to give ethyl acetoacetate?
  3. Chemistry

    A decomposition reaction is one in which a reactant decomposes to a limiting reactant and a theoretical reactant. True or False
  4. advanced chem

    Calculate the standard cell potential at 25 ∘C for the reaction X(s)+2Y+(aq)¨X2+(aq)+2Y(s) where ƒ¢H∘ = -653 kJ and ƒ¢S∘ = -263 J/K .
  5. Physics

    Two steel blocks are at rest on a frictionless horizontal surface. Block X has a mas of 3.0 kg ans is attacthed by means of a light taut string to block Y that has a mass of 12 kg. A force of 45 N (E) is applied to block x. Calculate the force block Y exerts on block x. I don'...
  6. Chemistry: Bunsen Burner Lab

    Hi! I have recently completed a bunsen burner lab and need help with a few conclusion questions: 1) What kind(s) of energy is released by the reaction of fuel and air in this system? 2) Which part of the Bunsen flame is hottest? How do you know? ->I researched it and know ...
  7. Calculus

    The temperature of a pan of hot water varies according to Newton's Law of Cooling: dT/dt=-k(T-A), where T is the water temperature, A is the room temperature, and k is a positive constant. If the water cools from 90°C to 85°C in 1 minute at a room temperature of 30°C, how ...
  8. chemistry

    supposed the theoritical yield in a reaction is 68.8g, and the percent yield is 66.0%, what is the actual yield of product obtained?
  9. chemistry

    Give the balance chemical reaction from the following decays.(a) loss of B^+ by ^15,8 O (b) loss of B^- by ^Ag (c) loss of * by ^46,62Sn
  10. Chemistry

    Suppose that 85 mL of 0.4 M NaF and 50 mL of 0.4 M HCl are mixed. What is the K for the dominant equilibrium in terms of Ka's, Kb's, Kw etc.? Ka of HCl 1/Ka of HCl Ka of HF 1/Ka of HF Kb of F- 1/Kb of F- Kb of Cl- 1/Kb of Cl- Kw 1/Kw There is no reaction.
  11. Physics Homework

    1. You push a heavy car by hand. The car, in turn, pushes back with an opposite but equal force on you. Doesn’t this mean the forces cancel one another, making acceleration impossible? Why or why not? -No, because of the system that is involved. The system would be you and ...
  12. math

    suppose there is a 2-degree drop in temperature for every thousand feet that an airplane climbs into the sky.If the temperature on the ground which is at sea level is 52 degres what would be the temperature when the plane reaches an altitude of 27,000 ft.
  13. math (27)

    suppose there is a 3-degree drop in temperature for every thousand feet that an airplane climbs into the sky.If the temperature on the ground which is at sea level is 63 degrees what would be the temperature when the plane reaches an altitude of 30,000 ft.
  14. Physical Science

    A long distance swimmer, who is very cold, m=100 kg., 1000 kilocalories are supplied to warm them up. The specific heat for a human is 0.83. A) What will be the temperature change? B) If the original temperature is 85 degrees, find the final temperature.
  15. Chemistry

    How much ice (in grams) with the temperature of 0∘C would have to melt to lower the temperature of 355mL of water from 26∘C to 4∘C? (Assume the density of water is 1.0 g/mL.)
  16. Calculus

    The temperature of a pan of hot water varies according to Newton's Law of Cooling: dT/dt=-k(T-A), where T is the water temperature, A is the room temperature, and k is a positive constant. If the water cools from 90°C to 85°C in 1 minute at a room temperature of 30°C, how ...
  17. Calculus

    The temperature of a pan of hot water varies according to Newton's Law of Cooling: dT/dt=-k(T-A), where T is the water temperature, A is the room temperature, and k is a positive constant. If the water cools from 90°C to 85°C in 1 minute at a room temperature of 30°C, how ...
  18. chemistry

    Can you check what I did below? On the first problem, I am not sure if I am suppose to add a negative to the first part of the heat loss of water like so -[C(sp)m(w)deltaT(w)]. On the second problem, part(a), I am not sure if I am using the mass from the first problem, 135g, ...
  19. chem

    For the following equilibrium system, which of the changes will form more CaCO3 (more moles CaCO3)? CO2 + Ca(OH)2=CaCO3 +H2O delta H =-113kJ Write and explain if amount CaCO3 decrease, no change or increase with regards to the following situations: a) Decrease temperature at ...
  20. science

    A heat exchanger is used to warm apple cider using steam as the heat source. The cider is heated from an initial temperature of 4 degrees celcius to a final temperature of 65 degree celcius. The steam enters the heat exchanger as 50% quality steam and exits as water condensate...
  21. chemistry

    write an equilibrium constant expression for the reaction of acetylene gas with hydrogen gas to produce methane gas.
  22. Chemistry

    Determine whether the following reaction is endothermic or exothermic: Mg(g) + 2 F (g)--> Mg 2+(g) + 2 F- Mg: I1= 738 kJ/mol I2= 1451 kJ/mol F: EA= -328 kJ/mol
  23. Chemistry 2

    Calculate Kp for the reaction C(s)+CO2(g)<-->2CO(g) kp=? C(s)+2H2O(g)<--->CO2(g)+2H2 kp1=3.47 H2(g)+CO2(g)<--->H2O(g)+CO(g) kp2=0.735
  24. chemistry

    find the heat of reaction deltaT = -95.7KJ 2 Al2 O3(s) > 4Al (s) + 3 O2 (g) a. - 95.7kj b. +95.7kJ c. -47.8 KJ d. +47.8KJ e. +191.4KJ
  25. chemistry

    A 52.3 kg sample of ethanol is needed for a reaction. What volume in liters of ethanol should be used? The density of ethanol is 0.789 g/mL
  26. Reading - Rip Van Winkle By Washington Irving

    (a) What is Rip's reaction when he reenters the village? (b) How do the villagers react to rip?
  27. physics

    A cannonball is shot (from ground level) with an initial horizontal velocity of 33.0 m/s and an initial vertical velocity of 25.0 m/s. What is the initial speed of the cannonball?
  28. chemistry

    A voltaic cell is contructed in which a copper wire is placed in a 1.0 M Cu(NO3)2 solution and a strip of gold i placed in a 1.0 M AuNO3 solution. The measured potential of the cell is found to be 1.36V and the copper electrode is negative. The Ered for the Cu2+/Cu half- cell ...
  29. Chemistry

    An ideal gas originally at 0.8 atm and 77C was allowed to expand untel its final volume ,pressure and temperature were 600 ml ,0.4 atm and 27C.what was the initial volume
  30. Chemistry

    A professor orders 250 mL of house coffee at precisely 95°C. She then adds enough milk at 10°C to drop the temperature of the coffee to exactly 90° C. Calculate the amount of milk (in mL) the professor must add to reach this temperature. Assume that the coffee and milk have...
  31. math

    a cold front moves in at noon and in 5 hours, the temperature had dropped 23%. the temperature at 5:00 p.m. was 14%. let x be the temperature at noon. write an equation to find x.
  32. physics

    the temperature of a body falls from 30C to 20C in 5 minutes. The air temperature is 13C. Find the temperature after a further 5 minutes.
  33. math

    The temperature outside was 3 degrees Fahrenheit at midnight. During the next hour the temperature fell 7 degrees. What was the temperature at 1 A.M. Can u explain to me how to do it please
  34. Math

    The temperature one spring day was 78 degrees. Starting at 1:15 pm the temperature drops 0.25 degrees per minute. What temperature will it be at 1:25 pm? Do I divide 0.25/1:25 to get the answer?
  35. Chemistry-Dr.Bob222

    Like a equilibrium constants, the values of Kw depends on temperature. At body temperature (37 C), Kw= 2.4 x 10^-14. What are the [H3O+] and pH of pure water at body temperature?
  36. Math

    Between 1am and 3am the temperature fell by 9C. Over the next hour, the temperature rose by 2C, Reaching -3C by 4am. What was the temperature at 1am?
  37. Physics

    a beaker contains 500g of water at a temperature of 80 C. How much ice at a temperature -20 C must be dropped in the water so that the final temperature of the system will be 50 C
  38. math

    The temperature outside changed from 69°F to 45°F over a period of eight days. If the temperature changed by the same amount each day, what was the daily temperature change? A.-24°F B.24°F** C.-3°F D.3°F
  39. lae school

    a storm front went through and the temperature dropped 10celsius in 3hr. If the temperature started at 6celsius, what was the temperature after the 3hr?
  40. algebra

    Suppose the temperature outside is dropping at a constant rate. At noon , the temperature is 70 degrees f and it drops to 58 degrees f at 5:00 P.M. How much did the temperature change each hour?
  41. Math

    At noon temperature was38degree Celsius.temperature decreases at rate of 6 degree Celsius per hour. What will be the temperature of room after....... Hours
  42. physics question

    For a science fair competition, a group of high school students built a kicker -machine that can launch a golf ball from the origin with a velocity of 11.2m/s and initial angle of 31.5° with respect to the horizontal. a) Where will the golf ball fall back to the ground? b) ...
  43. Dr.Bob, response to your reply to last answer

    Sorry, I didn't see this. Actually you have only one mixture; it happens to have two components. There is a more or less standard procedure for separating complete unknowns (that's where you know nothing about it) and if you know nothing about it that is where you start. You ...
  44. Chemistry

    If a strong acid or base is dissolved in water, will all of its parts have the concentration? For example in Ca(OH)2 = Ca + 2OH if the concentration of Ca(OH)2 is 8.11x10^-3 M, would the concentrations of Ca and 2OH be the same? or in the case of OH, the concentration has to ...
  45. math

    A cold front caused the temperature to drop to 21f. The temperature after the drop was 36f. Write and solve an equation to find the temperature before the temperature dropped. my answer is 57f. my equation is 36f=21f-f
  46. Chemistry

    Okay, I feel like this question should be really easy because it's a multiple choice question but how do you figure it out?? I'm completely drawing a blank. Consider the following equilibrium N2O4(g) <-> 2NO2(g) Kc = 4.8E-3 Which set of concentrations represents ...
  47. engineering

    A thermometer is used to measure the temperature of a gas flow through a pipe. The gas temperature is read at 500°C and the duct temperature is measured to be 350°C. The thermometer is cylindrical with a diameter of 1 mm and an intrusion length of 1 cm. It can be assumed ...
  48. Physics

    A certain type of ideal gas at pressure p0 is contained in a plugged flask of volume V initially at temperature T1 . The environmental pressure remains constant p0 . (a) As the flask is heated up to temperature T2 , the plug pops out. What is the pressure p2 of the ideal gas ...
  49. Food Chemestry

    A heat exchanger is used to warm apple cider using steam as the heat source. The cider is heated from an initial temperature of 4 degrees celcius to a final temperature of 65 degree celcius. The steam enters the heat exchanger as 50% quality steam and exits as water condensate...
  50. Physics

    Determine the amount of energy required to raise the temperature of 250 grams of steel from a temperature of 15 oC to a temperature of 40 oC . The specific heat of steel is 0.11 cal/gram oC.
  51. Chemistry

    I don't get how to fill in the blanks Show the products for cellular respiration by completing the following chemical reaction equation. Give the correct formula for oxygen as well Glucose+_________ ---> ________+______+___________
  52. chemistry

    "a test liquid has a density of 1.1g/ml.. when u pour some of it into a cup of water what will happen asuming thar their nature are such that they don't mix and that their is no chemical reaction between the two substance? please help !!!
  53. Global

    One way in which the Sepoy Mutiny in India, the Zulu resistance in southern Africa, and the Boxer Rebellion in China are similar is that each resulted from native reaction to foreign interference in the region, correct?
  54. Chemistry

    What volume of benzene (C6H6, d= 0.88 g/mL, molar mass = 78.11 g/mol) is required to produce 1.5 x 103 kJ of heat according to the following reaction? 2C6H6(l)+15O2(g)-->12CO2(G)+6H2O(g) :delta:Hrxn=-6278kj
  55. chemistry

    What is the minimum amount of 5.0M H2SO4 necessary to produce 24.1g of H2(g) according to the following reaction? 2Al(s) + 3H2SO4(aq) produces Al2(SO4)3(aq)+3H2(g). Express your answer using two significant figures.
  56. physics

    Identify the action-reaction paris in the following situations: a) a person takes a step b) a snowball hits someone in the back c) a footbal player catches a ball d) a leaf falls to the ground HELP
  57. chemestry

    Consider once again the magnesium nitride addition reaction from the previous question. This time, suppose you start with 10.0 g N2 and an unlimited supply of Mg. What is the maximum number of MOLES of Mg3N2 that could be produced in this case?
  58. chemistry

    follows first-order kinetics and has an activation energy of 244 kJ mol-1. At 684 K, k = 0.00000508 s-1. What is the half-life (min) for this reaction at 427 °C ? Round your answer to 3 significant figures. I really don't know what to do
  59. Chemistry

    If .002 L of .650 M NaOH are added to 1.0 L of 0.9 M CaCl2 what is the value of the reaction quotient and will a precipitate form? I keep getting 0.0011 because I thought the answer was [Ca+][OH-] but that's not correct, I think I'm missing a final step
  60. 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
  61. Chemistry

    the equation is TiCl4 + O2 (yields) TiO2 + 2Cl2. How much titanium(IV) chloride must react with excess oxygen to prepare 175 grams of the pigment? The reaction is found to be 85% efficient? (%yield)??
  62. chemistry

    Balance each of the following redox equations using the half-reaction method. HI(s) + H2SO4 (aq) --> H2S(g) + I2 (s) My only question about this equation is...how do I know how many electrons I need to put on both sides? Other than that I know how to do it.
  63. Chemistry

    consider the following reaction: 2CH3OH(g) yields 2CH4(g) + O2(g) change in enthalpy= 252.8kJ How many kilojoules of heat are released when 38.4 g of CH_4 g) reacts completely with O2 (g) to form CH3OH (g) at constant pressure?
  64. chemistry

    480 g of FeS2 is combined with 12.000mol of molecular oxygen. balanced chemical reaction is 4FeS2 + 11O2 ---> 2Fe2O3 + 8SO2 a. Which cheical will run out first? b. What mass of Fe2O3is produced?
  65. Chemistry

    1) given the following equation : Na2O 2Hl__>2Nal H2O (501.6KJ) a) 1f 9g of Nal are formed by the process, how much heat(q)will be involved? b) state whether the reaction is endorthermicor exothermic
  66. 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?
  67. Chemistry answer check

    What quantity of heat is required to produce 5 mol of oxygen gas by this reaction? HgO(s) → Hg(l) + ½ O2(g), ΔH = +90.7kJ I calculated 90.7*5, but my online homework says its wrong how do I calcuate this?
  68. Organic Chem

    adding one equivalent of sulfuric acid to 2,4-hexadiene gives 2 possible products. Give the structure and write all steps in the reaction mechanism that explains how each product is formed
  69. AP Chemistry

    We drop 30 grams of magnesium into 770 mL of a 4 M HCl solution. What is the maximum volume of dry hydrogen that could be produced by this reaction at STP? Mg(s) + 2HCl(aq)→MgCl2(aq) + H2(g) Answer in units of liters
  70. Chemistry

    Write the balanced chemical equation for each of the following. (Use the lowest possible coefficients. Include states-of-matter at 1 atm and 25unknown_prefixC in your answer.) (b) the reaction of magnesium metal and hydrobromic acid
  71. chemistry help fast

    The following reaction occurs in a blast furnace Fe2O3 +3Co--------2Fe+3Co2 Calculate the mass of carbon monoxide needed to reduce 16 tones of iron (111) oxide
  72. 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 ?
  73. Chemistry

    use the appropriate standard reduction potentials in the appendix of your book to determine the equilibrium constant at 285 K for the following reaction under acidic conditions 4H+(aq) + MnO2(s)+2Fe+2(aq)----> Mn+2 (aq)+2Fe3+(aq)+2H2O(l)
  74. Chemistry

    use the appropriate standard reduction potentials in the appendix of your book to determine the equilibrium constant at 285 K for the following reaction under acidic conditions 4H+(aq) + MnO2(s)+2Fe+2(aq)----> Mn+2 (aq)+2Fe3+(aq)+2H2O(l)
  75. chemistry

    how many moles of NH3 does it take to make 8.0 mol of H20 according to the reaction shown below? 4NH3 + 5O2 --> 4NO + 6H2O I REALLY NEED HELP WITH THIS AS I AM LOST. PLEASE PROVIDE NOTES.
  76. Chemistry

    Barium sulfate, BaSO4 is made by the following reaction. Ba(NO3)2(aq) + Na2SO4(aq)----> BaSO4(s) + 2NaNO3(aq) An experiment was begun with 91.77 g of Ba(NO3)2 and an excess of Na2SO4. After collecting and drying the product, 62.3 g of BaSO4 was obtained. Calculate the ...
  77. earth science

    If the temperature at the surface is 230 C, what is the temperature at a height of 2 km under average conditions (when temperature decreses with height by 6.50 C per km)?
  78. algebra1

    friday's temperature was 20 degrees warmer than monday's temperature t. write an expression for friday's temperature.... my answer is 20dregees + T is that correct?
  79. math

    At 9:00 pm the outside temperature was 20 celcius, by midnight the temperature had dropped x degrees. Which of the following represents the midnight temperature? 20 + x 20-x 20 20x
  80. math

    One day at 3:00 a.m., the temperature was -13 degrees f in Kodiak, Alaska. At 10:00 a.m., the temperature was 22 degrees f. What was the average change in temperature per hour?
  81. Math

    On average, the temperature falls about 5.4 F for every 1,000 ft of additional altitude. If the temperature is 42 F on the ground estimate the temperature at 5,000 ft
  82. math

    what is the temperature at the top of the stratosphere if the sea level temperature was 22 degrees and air temperature decreases 6 degrees every 1km
  83. Chemistry

    Like a equilibrium constants, the values of Kw depends on temperature. At body temperature (37 C), Kw= 2.4 x 10^-14. What are the [H3O+] and pH of pure water at body temperature?
  84. Math

    One day at 3 am., the temperature was -13 Fahrenheit in Kodiak, Alaska. At 10 am the temperature was 22 Fahrenheit What was the average change in temperature per hour?
  85. Appoquinimink School

    One winter night the temperature dropped 3 degrees every hour. If the temperature was 0 degrees at midnight,what was the temperature at 4:00 am?
  86. chem

    Which statement is wrong? 1. Adding the same amount of heat to two different objects will produce the same increase in temperature. 2. When the same amount of heat produces different changes in temperature in two substances of the same mass, we say that they have different ...
  87. Chemistry

    X + Y --> Q The reaction above has the rate law: rate = k[X]³. When [X] is doubled the rate increases by a factor of ?
  88. Chemistry I

    iF THE THEORETICAL YIELD IF A REACTION IS 0.121G AND THE ACTUAL YIELD IS 0.112G WHAT IS THE PERCENT YIELD
  89. chemistry

    If the theoretical yield of a reaction is 0.173g and the actual yield is 0.165g , what is the percent yield?
  90. chemistry

    What happens to the following reaction at equilibrium if the pressure is decreased? 2H"subtext"2(g) + O"subtext"2(g) 2H"subtext"2O(g)
  91. Chemistry

    I am having trouble with this question: A byproduct is chloroform (CHCL3) , a suspected carcinogen produced when HOCL, formed by the reaction of CL2 and water, reacts with dissolved organic matter. If a solution consist of 100 ppb of CHCL3 in drinking water, convert this ...
  92. college

    how can you differentiate between oxalic acid, citric acid and tartaric acid with CaCl2 test? show the chemical reaction?
  93. ap chemistry

    A titration. 12.46 mL of KMnO4 are titrated with 25 mL of H2C2O4. The half reaction is 2H2O+H2C2O4 ARROW 2H2CO3+2H+2e-. How do I get the molarity of H2C2O4? PLEASE HELP
  94. ap chemistry

    A titration. 12.46 mL of KMnO4 are titrated with 25 mL of H2C2O4. The half reaction is 2H2O+H2C2O4 ARROW 2H2CO3+2H+2e-. How do I get the molarity of H2C2O4? PLEASE HELP
  95. Biology

    What are the three reaction pathways which pyruvate undergoes in the metabolic pathways inside the cell and what are the names of the final products of each of these pathways?
  96. Chemistry

    Silicon Carbide, SiC,is prepared using the chemical reaction: SiO2 + 3C ---> SiC +2CO How many grams of SiC can be produced from 15.0g of C? Thanks!
  97. Physics

    Distance DC = FE = HG = AB = 2.7m FH = FD = GE = EC = CB = 2 m Find the supporting reaction of H, Member BD (Tension Force), Member CE, and Member CF? Figure Links: freeimagehosting 72dje
  98. Chemistry!!

    Complete and balance the reaction of A) (CH3)2NH(aq)+CH3COOH(aq)→ B) CH3CH2NH2(aq)+HBr(aq)→ C) CH3NH2(aq)+HCOOH(aq)→
  99. Chem

    Complete and balance the reaction of A) (CH3)2NH(aq)+CH3COOH(aq)→ B) CH3CH2NH2(aq)+HBr(aq)→ C) CH3NH2(aq)+HCOOH(aq)→
  100. Chemistry

    In the reaction between bromine and sodium, a bromine atom gains an electron. What ion is formed? Is the bromine oxidized, or is it reduced?
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