1. chemistry

    Do any of you think that spontaneous combustion is possible? If a reaction brings about an increase of entropy (increase in randomness) and also exodermic, then a reaction is spontaneous. Right? Yes, I think spontaneous combustion is possible. It happens.
  2. Chemistry

    Recall that all aqueoous solutions contain_____. Water can also undergo ____. This process is called the ______of water. The reaction can be written as: Notice the double arrow in the reaction. This indicates that the reaction is_____. However, only a tiny
  3. Chemistry

    Which of the following is the best definition of Hess' Law? A. Heat evolved in a given process can be expressed as the sum of the heats of several processes that, when added, yield the process of interest. B. The enthalpy of a process is the difference
  4. Chemistry - Enthalpy reactions

    What is the reaction enthalpy for CaCO3(s) --> CaO(s) + CO2(g)? should i be using a enthalpy reaction table?
  5. chem

    Complete the reaction? IF no reaction say so H2O C4H6O3 ====> H2O c) Cu ===== > H2O d) K2O=====> e) 2 NaNO3 + ht →
  6. science

    humidity is the amount of water vapor in the air ata given time.if the air at 75degrees holding the maximum amount of moisture it can,and the temperture suddenly drops to 60 degrees,what is likely to happen? a)percipitation will be released in the form of
  7. chemistry

    already missed question so I just need help figuring out what I did. Small amounts of chlorine gas can be gener- ated in the laboratory from the reaction of manganese(IV) oxide with hydrochloric acid: 4 HCl(aq) + MnO 2 (s) → 2 H 2 O( ℓ ) + MnCl 2 (s) +
  8. Chemistry (equilibrium)

    C2H6(g) <=> C2H2(g) + 2 H2(g) The ΔH° for the reaction above is +312 kJ. The system is initially at equilibrium. In which direction will the reaction shift in each of the following situations? e) The temperature is decreased. g) He is added at
  9. BIOLOGY

    Can TAMIFLU form a hydrogen bond with another molecule? Can TAMIFLU form a ionic bond with another molecule? Can TAMIFLU form a van der Waals forces bond with another molecule?
  10. french- affirmative commands

    When you are putting a verb into the tu form of an affirmative comand like don't eat any. Why is it N'en mange pas and not manges (the tu form of manger)
  11. Pre Calc

    Derive the equation of the locus of all points that are equidistant from the point F(-3,4) and the line y=-2. Leave your answer in general form. [General Form: ax^2+by^2+cx+dy+e=0]
  12. algebra

    Rewrite into standard form (0,5), m=-3/5. Write the equation of the line passing through each of the given pairs of points. Write the answer in slope-intercept form, where possible. (2,-3) and (2,4)
  13. English

    1. He often takes pictures of sunrises/sunrise. (Do we have to use the singular form or the plural form?) 2. What's wrong with your brother? - No, not at all. (Is this answer suitable? Do you have other suitable answers?)
  14. Algebra

    Write an equation in standard form (slope-intecept form) of the line passing through the pair of points (3,4) and (5,8) containing point (5,9) and parallel to the line.
  15. Algebra

    Rewrite into standard form (0,5), m=-3/5. Write the equation of the line passing through each of the given pairs of points. Write the answer in slope-intercept form, where possible. (2,-3) and (2,4)
  16. chemistry

    The body-centered cubic unit cell of a particular crystalline form of silver is 2.2887A on each side. Calculate the density of this form of silver?
  17. Spanish

    Write the correct form of ser. Tu y tus padres________________de Puerto Rico? Which is the correct form? 'son' or 'sois' and why? Muchas Gracias
  18. Science

    For example HNO2 + H20 ----> H30+ NO2- I don't understand how the hydronium ions form. How do I figure out if a OH- or H30+ will form from the reactant side.
  19. French

    Which form of conjugation would I use for the following? Like would I use the tu, vous, nous, il, elle, etc. form for which one? -Les enfants -Ma famille -Les adultes -Ces fruits coupes Thanks
  20. Pre-Calculus

    Find a solution to the equation if possible. Give the answer in exact form and in decimal form rounded to three decimal places. 1=21tan(2x+2)-6
  21. Chemistry

    How do write a skeleton equation for this reaction? When heated, baking soda (sodium hydrogen carbonate) decomposes to form the products sodium carbonate, carbon dioxide, and water. Can someone please break it down so i can see how you got that ansewer?
  22. Chemistry

    In order for the reaction 2Al(s) + 6HCl(aq)→2AlCl3(aq) + 3H2(g) to occur, which of the following must be true? A. Al must be above Cl on the activity series. B. Al must be above H on the activity series. C. Heat must be supplied for the reaction. D.
  23. chemistry

    In the reaction A to products, A is found to be 0.489 M at t=72.0 s and 0.468 M at t=82.2 s What is the average rate of the reaction during this time interval? Do I take the Ln (0.468/0.489) = -0.04395 / 10.2 = 4.3 * 10^3. yet the comp says its wrong. i
  24. Chemistry

    Consider the generic reaction: 2 A(g)+ B(g)--> 2C(g). If a flask initially contains 1.0 atm of A and 1.0 atm of B, what will be the pressure in the flask if the reaction proceeds to completion? (Assume constant volume and temperature.) answer is 1.5atm
  25. chem

    7.82 SILVER(I) NITRATE REACT WITH POTASSIUM CHLORIDE FIND THE BALANCED CHEMICAL REACTION USING THE GIVEN MASS FIND THE MASS OF THE REAGENT. ALSO CALCULATE THE MASSES OF THE PRODOUCT FORMED IN THE REACTION
  26. Chemistry

    Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: A 2.00-g sample of is reacted with 1.93 g of . How many grams of water remain after the reaction is complete? 0.0714 1.29 0.00 1.04 0.00396
  27. chemistry

    n an experiment, Ann mixes concentrated sulfuric acid with water in a reaction test tube. The walls of the test tube turn hot. What type of reaction has occurred?
  28. Chemistry

    Suppose NaOH is added to the following system when it is at equilibrium. NH3 (aq) + H2O (l) = NH4 (aq) + OH (aq) a) in which direction will the reaction shift after the NaOH is added? b) will this stress increase or decrease the value of the reaction
  29. Chemistry

    Consider the following chemical reaction: C (s)+ H2O(g) --> CO(g)+ H2(g) How many liters of hydrogen gas are formed from the complete reaction of 1.20 mol of C? Assume that the hydrogen gas is collected at a pressure of 1.0 atm and temperature of 310 K.
  30. College Chemistry

    Animals break down glucose (C6H12O6) as a source of energy according to the following overall reaction. C6H12O6(aq) + 6O2(g) ¨ 6CO2(g) + 6H2O(l) What mass in grams of CO2(g) is produced from the reaction of 15.0 g of glucose?
  31. chemistry

    A voltaic cell is constructed based on the following reaction and initial concentrations: Fe^2+,( 0.0055 M ) + Ag+,( 2.5 M ) ----> Fe^3+,( 0.0055 M ) + Ag(s) <---- its a forward and reverse arrow Calculate [Fe^2]+ when the cell reaction reaches
  32. general chemistry

    In a study of the effect of alcohol dehydrogenase on alcohol at 25.0 °C, the concentration of ethanol in a first-order reaction decreased from 220.0 mmol/L to 56.0 mmol/L in 1.22 x 104s. What is the rate constant for the reaction at 25.0 °C?
  33. chemistry

    Ethylene gas (C2H2) can be formed from the reaction of calcium carbide (CaC2) with water. What is the reaction rate if 14.2 grams of ethylene gas are produced over 4.00 seconds? The units are mol/s.
  34. Chemistry Honors

    At a particular temperature, 12.0 mol of NH3 is introduced into a 2.0 container, and the NH3 partially dissociates by the reaction: 2NH3 <> N2 + 3H2 At equilibrium, 6.0 mol of H2 gas are present. Calculate the K for this reaction.
  35. chemistry

    In an experiment, Ann mixes concentrated sulfuric acid with water in a reaction test tube. The walls of the test tube turn hot. What type of reaction has occurred?
  36. chemistry

    Write the equations describing the electrode reactions and the net cell reaction for this electrochemical cell containing indium and cadmium: This is what I have so far: anode: In(s) --> In^3+ + 3e- cathode: Cd^2+ + 2e- --> Cd (s) Need help writing
  37. chem

    The full inoic equation for an electrochemical cell is Br2 + Zn yields 2Br- + Zn2+. write the half reaction that occurs at the anode and the half reaction that occurs at the cathode
  38. biology

    The conversion of molecule S to product P has a Keq = 2.0. Two different, but related enzymes, A and B, can catalyze the reaction. The product P serves as an allosteric inhibitor of enzyme B, but not of enzyme A. A. 10 mM S is placed into three separate
  39. Visual Basic Programming...Very Urgently!!!

    Please Can someone help in proving the code about transactiopn program of images. it must have a two diffetrent form that will perform simultaneously which menas that first form will have login password to log in to use the transaction. Please your help is
  40. Maths

    How many silver coins ,2cm in diameter and of thickness 2mm,must be melted to form a showpiece in the form of frustum of a cone having height 9cm and radii of outer circular ends as5cm 3cm
  41. English check

    1. Which description fits the limerick about the fellow named Hall? 1)a poem about something funny with five lines. ****** 2)a serious poem without rhyme 3)a love poem with rhymes and rhythm 4)a poem about nature with three lines 2. The rhythm and rhyme
  42. chemistry

    Precipitation Reactions Write a molecular equation for the precipitation reaction that occurs (if any) when the following solutions are mixed. If no reaction occurs, write NO REACTION. Express your answer as a chemical equation. Identify all of the phases
  43. Chemistry Check

    Just want to make sure that my thought process is right on this one. 5 compounds: n-butyl chloride n-butyl bromide sec-butyl chloride tert-butyl chloride and crotyl chloride Each is reacted with NaI (SN2?) and AgNO3 (SN1?) And we have to rank the reaction
  44. 8th grade math

    How do you turn these equation into a standard form? this is the standard form: ax+by=c here are the following equations: 2x = y + 1/2 y - 2 = 1/4x + 1 3y + 3 = 6x - 15 Please help and explain. Thank you.
  45. Maath

    Find an equation of the line L in point slope form and in general form. L is parallel to the line 3x-2y+5=0 and contains (2,3)
  46. biology

    Which of the following elements is most likely to form an ion that will then form an ionic bond with an ion of a Group 1A element? Be I Fr **my choice Pt
  47. 4th grade

    write 31 hundred thousands in standard form and 23 ten thosands in standard form
  48. Chem

    If I were to use dichromate and add HCL and Ba(NO3)2 and NaOH , what should form? Im thinking the Ba(NO3)2 would still form a precipitate but im not too sure about everything else
  49. Chem

    If I were to use dichromate and add HCL and Ba(NO3)2 and NaOH , what should form? Im thinking the Ba(NO3)2 would still form a precipitate but im not too sure about everything else
  50. math

    give an example of rational number in fraction form. write your rotational number in its decimal form.
  51. Chemistry

    Can b2h6 react with alkene to form trialkyborane or diborane actually splits like this b2h6 to form 2bh3
  52. Math

    Use the digits 4'5'6'7' and 8 once each to write an odd five-digit number . Write it both in standard form and in word form
  53. precalc

    does anyone know the general form equation of a circle with a center (4,5) that passes through (-1,2) ...and just checking, would the standard form equation be: (-1+4)^2 + (2+5)^2 = 58
  54. 11th grade algebra 2

    (1-7) write each function in vertex form (8-10) write each funtion in standard form? 1) Y=x^2+3x-10 2) Y=x^2-9x 3) Y=X^2+x 4) Y=x^2+5x+4 5) Y=4x^2+8x-3 6) Y=(3/4)x^2+9x 7) Y=-2x^2+2x+1 8) Y=(x-3)^2+1 9) Y=2(x-1)^2-3 10)Y=-3(x+4)^2+1
  55. Algebra

    i have to take the standard form of the Equation 11x - 4y = 32 and change it to slope- Intercept form y = my + b Answer 4y = 11x - 32
  56. Chemistry

    Compare and contrast two elements combining to form a compound and two compounds combining to form a mixture.
  57. math

    sorry, but one more question... there are a couple questions that say something like write the equation 2x+3y-5=0 in normal form... but isnt it already in normal form?
  58. chemistry

    How many grams of NH3 form when 27.5L of H2 (measured at STP)react with N2 to form NH3 according to: N2(g) + 3H2 (g) = 2NH3 (g)
  59. Science

    Thermite is a mixture of iron(III) oxide and aluminum powders that is used in some countries to weld railroad tracks. It is a spectacular reaction to yield solid aluminum oxide that floats on the molten iron. When cooled, the iron is ground smooth and even
  60. Chemistry

    Hydrogen and methanol (CH3OH) have both been proposed as alternatives to hydrocarbon fuels. a) Write balanced chemical equations for the complete combustion of hydrogen and the complete combustion of gaseous methanol. Combustion reaction for hydrogen:
  61. chemistry

    Based on reaction kinetics, which of the following pairs of reactions and reaction rate equations represent elementary reactions? You may choose more than one reaction. Ti + 2Cl2 = TiCl4 Rate = k[Ti][Cl2] 2SO2 + O2 = 2SO3 Rate = k[O2][SO2]2 Na2S + CuSO4 =
  62. chemistry reaction rate

    2NO(g) + O2(g) → 2NO2(g) + 112 kJ what do you do to increase the reaction rate? decrease in pressure or increase in concentration of NO? HELP!
  63. Chemistry

    In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
  64. Chemistry

    In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
  65. chemistry

    For the following reaction, 2SO3(g) = 2SO2(g) + O2(g), the equilibrium constant, Kp, is 1.32 at 627 degrees Celsius. What is the equilibrium constant for the reaction: SO3(g) = SO2(g)+ 1/2 O2(g)
  66. chemistry

    The enthalpy change for the following reaction is -483.6 kJ: 2H2(g) + O2(g) = 2H2O(g) Therefore, the enthalpy change for the following reaction is _______ kJ: 4H2(g) + 2O2(g) = 4H2O(g)
  67. Chemistry-Dr.Bob 222

    1. The rate constant for a second order reaction has units of L mol^-1 s^-1. What are the units of the frequency factor, A, for a second order reaction?
  68. science

    Explaini why the observation if a preciiitate forming may be evidence of a chemical reaction.What other evidence would youneed to gather to be sure that a chemical reaction has taken place?
  69. chemistry

    what mass of acetylene, C2H2, will be produced from the reaction of 90 g of calcium carbide, CaC2, with water in the following reaction? CaC2+2H2O-->C2H2+Ca(OH)2
  70. chemistry

    The percentage yield for the reaction PCL3+Cl2-->PCL5 is 83.2%. What mass of PCL5 is expected from the reaction of 73.7g of PCL3 with excess chlorine?
  71. Chemistry

    Write the equation for the reaction associated with the Ka2 of sulfuric acid, H2SO4. Write the equation for the reaction associated with the Kb2 of carbonate, CO32–.
  72. Chemistry

    Write the equation for the reaction associated with the Ka2 of sulfuric acid, H2SO4. Write the equation for the reaction associated with the Kb2 of carbonate, CO32–.
  73. Chem

    Consider the following reaction was found to be the 0th order to A and 2nd order to B. 2A(cr) + 3B(aq) -->A2B3(cr) Write a rate law equation for the reaction rate of A with B.
  74. chemistry

    If delta G (Gibbs) is positive and you are trying to find at what temperature the reaction is spontaneous would the formula be: T< H/S ? G=H-TS H-TS>0 T< H/S then the temperature found would be the temp at which the reaction is spontaneous?
  75. Chemistry

    Calcium reacts with water according to the chemical equation below: Ca + 2H2O--> Ca(OH)2 + H2 All but which reaction is expected to occur on the basis of the reaction of calcium and water?
  76. Chemistry

    Calcium reacts with water according to the chemical equation below: Ca + 2H2O--> Ca(OH)2 + H2 All but which reaction is expected to occur on the basis of the reaction of calcium and water?
  77. Chem15

    The reaction CO(g) + H2O(g)--> CO2(g) + H2(g) has Kc = 102 at 500 K. If a reaction mixture initially contains 0.154 M CO and 0.154 M H2O, what will be the equilibrium concentration of H2?
  78. Chem II

    The rate constant for a reaction at 305.0 K is two times the rate constant at 295.0 K. The activation energy of the reaction is ______ kJ mol
  79. Biology (alert!)

    Which sentence do you think does not agree with the true facts of coral reefs? 1. Off shore coral reefs are the cause of terrible storms in coastal communities. 2. Coral reefs form when the shells of thousands of corals join. 3. Sponges gives out chemicals
  80. chemistry 102

    The following decomposition reaction SO2Cl2-->SO2 + Cl2 was run in a laboratory. Following data collected: Time(s) Pressure SO2Cl2 (ATM) 0 1 2500 .947 5000 .895 7500 . 848 10000 .803 What is the overall order of reaction?
  81. physical chemistry

    For the process CH4(g) = C(s) + 2H2(g) A reaction is started in a rigid vessel at 1000 K with 1 mole of methane and 1 mole of hydrogen gas at 10 bar. Use table C.3 from your text to determine how many grams of carbon should be formed after the reaction has
  82. Chemistry

    Over the years, the thermjte reaction has been used for welding railroads, in incendiary bombs, and to ignite solid fuel rocket monitors. The reaction is Fe2O3(s) + Al(s) ---> 2Fe(l) + AI2O3(s). What mass of iron (iii) oxide(rust) must be used to
  83. Chemistry

    Over the years, the thermjte reaction has been used for welding railroads, in incendiary bombs, and to ignite solid fuel rocket monitors. The reaction is Fe2O3(s) + Al(s) ---> 2Fe(l) + AI2O3(s). What mass of iron (iii) oxide(rust) must be used to
  84. math,correction

    Problem #1 subtract. Express your answer in simplest form (3x)/(18) minus (x)/(18) MY steps: (3x-x)/(18) = (2x)/(18) and answer: (2x)/(18) Problem #18 write in simplest form. (3x^5)/(15x^12) My steps: (3)/(15) = .60 x^5-12 = x^-7 so my answer is: .60x^-7
  85. English

    1.All of the balloons on the string (popped) except two. 2.Do you (want) to buy those books? 3.Daniel's dog is (following) the trail to the river's edge. 4.For thirty years the noon whistle has (blown) exactly on time. 5.The players have (challenged) their
  86. math

    A cat can walk 2,190 miles in 2 hours. How can 2,190/2 be written in expanded form? 1) 2,000+100+90/2 2)200+90+1/2 Write it in quotation form.
  87. math

    1. the speed of light is 8.0x^8m/s in standard form that is? 2. the average size of a virus is 2x 10^-10 nanometers in diameter. how to write the number(s) given scientific notation in standard form. thank you
  88. Chemistry!!!!

    A student mixed 50.0 mL of 0.50 M H2SO4 (aq) at 18.5 degrees C with 100 mL of 0.50 M NaOH (aq) at the same temperature. After the reaction was completed, the temperature rose to 22.0 degrees C. What was the heat of reaction? (Assuming the densities of the
  89. chem

    Calculate the standard enthalpy change for the reaction 2A+B->2C+D Use the following data: Substance A=-257kj/mol B=-413kj/mol C=189kj/mol D=-475kj/mol For the reaction given , how much heat is absorbed when 3.00mol of A react?
  90. Chemistry

    You are staying the reaction A2 (g)+B2 (g)=2AB (g) To determine its rate law .Assuming that you have a valid experimental procedure for obtaining (A2)& (B2) at various times, explain how you determine (a)the initial, (b) the reaction order, & (c) the rate
  91. chemistry

    In a study of the alcohol dehydrogenase catalysed oxidation of of ethanol at 25.0 C, the molar concentration of ethanol decreased in a first-order reaction from 220.0 mmol/L to 56.0 mmol/L in 1.22 x 104s. What is the rate constant of the reaction at 25.0
  92. college chem

    In the reaction PCl5(g) ---> PCl3(g) + Cl2 (g) 0.200 mol of PCl5 is introduced into a 2.00 liter vessel. At equilibrium, the concentration of Cl2 is found to be 0.0500 molar. Find Kc for the reaction.
  93. Chemistry

    It's a molar heat reaction lab. 0.07g Mg Mg+2HCl->MgCl2+H2 What is the actual value for the heat of reaction based on the enthalpy's of formation? HfHCl= -118.53 kJ/mole HfMgCl2= -774 kJ/mole
  94. Chemsitry

    Consider the equilibrium A(g)=2B(g)+3C(g) at 25 degrees Celsius. When A is loaded into a cylinder at 10 atm and the system is allowed to come to equilibrium, the final pressure is found to be 12.13 atm. What is the standard gibbs free energy of reaction
  95. Chemistry

    A precipitation reaction takes place when a water solution of potassium phosphate, K3PO4, is added to a water solution of cobalt (II) chloride, CoCl2 Write a balanced equation for this reaction
  96. AP CHEM HELP

    When NH3 is added to solid Hg2Cl2, some of the mercury ions are oxidized and some are reduced. A reaction where the same substance is both oxidized and reduced is called a disproportionation reaction. Write equations for each of these half-reactions. HELP
  97. science

    Potassium iodide is prepared by the reaction of hydroiodic acid and potassium hydrogen carbonate. water and carbon dioxide are also produced. in the reaction of 398 g HI and 318 g KHCO3, how many grams of KI are produced?
  98. chemistry

    5.00g aluminum sulfide and 10.0g water react according to the reaction: Al2S3 + 6 H2O -> 2 Al(OH)3 + 3 H2S What is maximum mass of H2S that can be formed? What mass of excess reactant remains when the reaction is complete?
  99. chemistry

    2AgNO3 + Zn -> 2Ag + Zn(NO3)2 Put Zn 19g and excessive amount of AgNO3 together in a beaker and start reaction. When Zn is still in a beaker, stop the reaction, and measure the mess of (Zn+Ag). Mass of (Zn+Ag) was 29g. Than what is the mass of Ag in
  100. math

    The disney Golf classic starts with 64 golfers. the golfes form pairs and each pair plays amtch. the losers drop out nad the winners of each pair then form new pairs and play again. Then those winners form pairs and play. this continues until there is one