lyne

Most popular questions and responses by lyne
  1. chemistry

    Nitrogen (N2) and hydrogen (H2) react to form ammonia (NH3). Consider a mixture of six nitrogen molecules and six hydrogen molecules in a closed container. Assuming the reaction goes to completion, what will the final product mixture be? number of NH3

    asked on January 23, 2009
  2. chemistry

    The total acidity in water samples can be determined by neutralization with standard sodium hydroxide solution. What is the total concentration of hydrogen ion, H+, present in a water sample if 300. mL of the sample requires 7.5 mL of 2.8 10-3 M NaOH to be

    asked on March 26, 2009
  3. chemistry

    The element rhenium (Re) has two naturally occurring isotopes, 185Re and 187Re, with an average atomic mass of 186.207 amu. Rhenium is 62.60% 187Re, and the atomic mass of 187Re is 186.956 amu. Calculate the mass of 185Re. am i supposed to multiply the

    asked on January 5, 2009
  4. chemistry

    Hydrogen cyanide is produced industrially from the reaction of gaseous ammonia, oxygen, and methane. 2 NH3(g) + 3 O2(g) + 2 CH4(g) 2 HCN(g) + 6 H2O(g) If 5.00 x 10^3 kg each of NH3, O2, and CH4 are reacted, what mass of HCN and of H2O will be produced,

    asked on February 1, 2009
  5. chemistry

    a.Write the balanced chemical equation for the reaction of methane and sulfur. (Type your answer using the format CO2 for CO2. Use the lowest possible coefficients.) 1CH4 + 4S --> 1CS2 + 2H2S (b) Calculate the theoretical yield of carbon disulfide when

    asked on January 27, 2009
  6. chemistry HELP

    A 46.2 gram sample of copper is heated to 95.4 degrees celcius and then place into a calorimeter containing 75.0 grams of water at 19.6 degrees celcius. The final temp of the water and copper is 21.8 degrees celcius. Calculate the specific heat capacity of

    asked on January 2, 2009
  7. chemistry

    Ca(s) + Br2(l) --> CaBr2 is synthesis my teacher also said that the cause of the reaction is stable electron configuration is that the same thing as the electrolytes one

    asked on January 20, 2009
  8. chemistry

    A student prepared aspirin (C9H8O4) in a laboratory experiment using the following reaction. C7H6O3 + C4H6O3 C9H8O4 + HC2H3O2 The student reacted 2.00 g salicylic acid (C7H6O3) with 2.67 g acetic anhydride (C4H6O3). The yield was 2.00 g aspirin. Calculate

    asked on February 4, 2009
  9. chemistry

    Consider the following unbalanced reaction. P4(s) + 6F2(g) 4PF3(g) How many grams of F2 are needed to produce 114. g of PF3 if the reaction has a 78.1% yield? i tried it and got this 114g PF3 x (mol PF3/87.97g PF3) x (6 mol F2/ mol PF3) x (38g F2/mol

    asked on February 4, 2009
  10. chemistry again :)

    A compound containing only sulfur and nitrogen is 69.6% S by mass; the molar mass is 184 g/mol. What are the empirical and molecular formulas of the compound? i solved for empirical and got a 1:1 ratio so it would be SN. for the molecular do i take

    asked on January 2, 2009
  11. math

    Define variables and write a system of equations for each situation. Solve using substitution. Suppose you are thinking about buying one of two cars. Car A will cost $17,655. Youn can expect to pay an average of $1230 per year for fuel, maintenance, and

    asked on April 2, 2009
  12. chemistry

    #2) Consider the preciditation reaction of a solution containing 3.50 grams of sodium phosphate mixed with a solution containing 6.40 grams of barium nitrate. How many grams of Barium phosphate can form? Ba(NO3 )2 + Na3 PO4 yields Ba3 (PO 4 )2 + NaNO3 #2b)

    asked on January 29, 2009
  13. chemistry

    What volume of .101 M HNO3 is required to neutralize each of the following solutions? there are four and i got them all right but this one... 51.1 mL of .127 M NH3 i got 193 mL can someone please help???

    asked on March 10, 2009
  14. chemistryy

    Most window cleaners are aqueous solutions of ammonia. A 9.00 mL sample of a particular window cleaner requires 42.95 mL of 0.0508 M HCl for its titration. What is the molarity of ammonia in the window cleaner? i am completely lost i cant even find the

    asked on March 26, 2009
  15. chemistry

    Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride (C4H6O3). The balanced equation is given below. C7H6O3 + C4H6O3 C9H8O4 + HC2H3O2 What mass of acetic anhydride is needed to completely consume 3.60 x 10^2 g salicylic

    asked on January 23, 2009
  16. chemistry

    why is COCl2 polar a. different electronegativities b. nonsymmetric c. tetrahedral d. symmetric e. trigonal planar more than one can be chosen also wht is HCN polar a. nonsymmetric b. different electronegativities c. trigonal planar d. linear e. bent f.

    asked on April 29, 2009
  17. chemistry

    Ca + Br2 --> CaBr2 its synthesis and the reason the reaction happens is stable electron configuration but i don't understand why. Responses chemistry - DrBob222, Wednesday, January 21, 2009 at 10:06pm Synthesis because it's two elements combining to form a

    asked on January 21, 2009
  18. chemistry

    How many grams of oxygen are required to react with 2.50 g of propane (C3H8) to form CARBON MONOXIDE and water? this is what i did why is it wrong? 2.50 g C3H8 x 1 mole / 44.09 g C3H8 x 5mole O2 / mole = 9.1 g O2 everything cancels to get grams of O2 which

    asked on January 22, 2009
  19. chem

    which element has a more favorable (exothermic) electron affinity? K Mg how do i determine this?

    asked on January 2, 2009
  20. chemistry

    Calculate the number of C, H, and O atoms in 4.50 g of glucose (C6H12O6), a sugar. okay i did it and i got just the C right and not the H and O help?

    asked on January 5, 2009
  21. Science

    what does the geologic time scale indicate about the change in life-forms over time?

    asked on March 30, 2009
  22. chemistry

    predict the identity of the precipitate that forms. calcium nitrate, Ca(NO3)2, and sodium chloride , NaCl why does the answer come out as no reaction? couldnt it form to be CaCl2 or NaNO3 i thought it had something to do with the fact that Na and NO3 are

    asked on January 13, 2009
  23. chemistry

    how many atoms of tungsten are in 504.56 g of tungsten(IV)acetate. i attempted this problem but ended up with atoms of tungsten(IV) acetate in tungsten(IV) acetate instead of atoms of just tungsten in tungsten(IV) acetate. please help thanks

    asked on June 7, 2009
  24. chemistry

    Write a chemical equation showing how each of the following species behaves as a base when dissolved in water a.) O2- i have O2- + H2O --> HO2- + OH- how do i make this right??

    asked on March 19, 2009
  25. chem

    what VSEPR "shapes" and bond angles do you find Toluene

    asked on September 1, 2009
  26. chemistry

    Calculate the hydrogen ion concentration and the pH of each of the following solutions of strong acids. (a) 0.00010 M HCl if you could just explain how to do this that would be great! thanks

    asked on March 23, 2009
  27. chemistry

    how many moles of hydroxide ions are there in 82.35 mL of a 2.164M Sr(OH)2 solution? i understand how to do the math for problems like these, but i don't know how to find the moles of just hydroxide ions.

    asked on March 15, 2009
  28. chem

    a certain substance strongly absorbs infrared light having a wavelength of 3.75µm. what is the frequency of this light in hertz? i know that i have to use the equation c = frequency x wavelength and that c = 2.998 x 10^8 m/s. how do i convert that to

    asked on January 2, 2009
  29. chemistry

    calcium hydroxide reacts in a neutralization reaction with sulfuric acid in a 1:1 ratio to form water and calcium sulfate. if you have 23.5 grams of calcium hydroxide, how many milliliters of water can you form? how do i use dimensional analysis to solve

    asked on December 12, 2008
  30. chemistry

    How do multiple bonds introduce rigidity into molecules? what is meant by rigidity??

    asked on April 28, 2009
  31. chemistry

    Chlorine dioxide, ClO2, has been used as a disinfectant in air conditioning systems. It reacts with water according to the following equation. 6ClO2 + 3H2O --> 5HClO3 + HCl If 142.0 g of ClO2 is mixed with 33.0 g of H2O, how many grams of the reactant will

    asked on February 2, 2009
  32. chemistry DRBOB

    Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pH values. pH=1.10 im guessing that this is what i did in my previous question except now i have to do it backwards. but i don't know how to do the

    asked on March 23, 2009
  33. chemistry

    How would you prepare 250.0 ml of a 0.6 M aluminum sulfate solution

    asked on March 2, 2009
  34. chemistry

    When ammonia gas is burned in oxygen the products formed are water and nitrogen monoxide gas. Write the balanced equation showing this reaction NH4 + O2 --> H2O + NO i am stuck balancing this

    asked on January 23, 2009
  35. chemistry

    Ca + Br2 --> CaBr2 its synthesis and the reason the reaction happens is stable electron configuration but i don't understand why.

    asked on January 21, 2009
  36. chemistry

    how do i balance the following(fill in the blanks): 1.) __BF3 + __Li2SO3 --> __B2(SO3)3 + __LiF 2.) __CaCO3 + __H3PO4 --> __Ca3(PO4)2 + __H2CO3 3.) __B2Br6 + __HNO3 --> __B(NO3)3 + __HBr

    asked on December 15, 2008
  37. chemistry 1

    k2=[H][SO4]/[HSO4] .012=(.01+x)(x)/(.01-x) Solve for x, and calculate pH where H is .01+x When I am solving for x does it become .012= .01x + x^2/ .01 -x.. what is the next step of solving for x?

    asked on March 26, 2008
  38. chemistry

    I have to draw the QMM of CL2C2. For the Lewis structure i think that the two C atoms form a triple bond and the Cl atoms form single bonds. Cl | C'triple bond'C | Cl Therefore i think that the central C atom hybridizes into sp. if this is correct, my

    asked on April 29, 2009
  39. CHEMISTRY

    How much water should be added to 45.0 mL of 0.225 M HCl to dilute the solution to 0.155 M? i did .225M x .045L / .155M = 65mL so wouldnt 20 mL be added?

    asked on March 4, 2009
  40. chemistry

    continued from before.... the question was what are three chemical characteristics and ten physical characteristics so then would i have to say something like -when iron rusts or -sugar burns or something like that i was thinking that would just be a

    asked on January 7, 2009
  41. chemistry

    The compound adrenaline contains 56.79% C, 6.56% H, 28.37% O, and 8.28% N by mass. What is the empirical formula for adrenaline? i worked the problem out and got C8O3N but its not right..what did i do wrong?

    asked on January 5, 2009
  42. Gen Chemistry

    What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second equilibrium depends upon the amount of [H+] already donated by

    asked on March 26, 2008
  43. chem

    if you were to react 14.00 grams of salicylic acid with 8.50 grams of acetic anhydride, what would your theoretical yield be? the reaction is C7H6O3+C4H6O3--> C9H8O4 + C2H4O2 assuming 1:1 ratio.

    asked on September 1, 2009
  44. chem

    how many grams of a precipitate will form when you mix 45 ml of a 3.5M silver nitrate solution with 45 ml of a 5.4 M magnesium chloride solution i sorted the problem but have no clue how to start

    asked on June 7, 2009
  45. chemistry

    what is the duet rule?

    asked on April 28, 2009
  46. Science

    how did geologists determine the divisions of the geologic time scale?

    asked on March 30, 2009
  47. chemistry HELP DRBOB

    Calculate the sodium ion concentration when 80.0 mL of 4.5 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate. how do i solve this I don't really know where to begin.. is there a formula for finding concentration because we don't learn this

    asked on March 10, 2009
  48. chemistry

    How much of each starting material would you use to prepare 2.00 L of each of the following solutions? 0.240 M NaOH from 1.00 M NaOH stock solution what do i do with the .100 M and .240 M??

    asked on March 4, 2009
  49. chem

    how do you prepare a solution using the proper lab equipment(both from dry solid and a stock solution) i researched it but all i found was the definition for stock solution any help please!!

    asked on February 12, 2009
  50. chemistry -IMPORTANT-

    we have to make an instrctinal packet showin relationships between moles and concentration. i cant find the following 1)how is the number of moles dissolved in a set amount of solvent related to the molarity? 2)how to determine the amount of solvent in

    asked on February 12, 2009
  51. chemistry

    3BaCl + 2Na3PO4 --> Ba3(Po4)2 +^NaCl is Ba3(PO4)2 the ppt. because Cl salts are soluble so it will dissolve?

    asked on January 21, 2009
  52. chemistry

    NaCl + CuSO4 to write the product would i just do double replacement to get Na2SO4 + CuCl2 so the whole thing would be 2NaCl + CuSO4 --> Na2SO4 + CuCl2

    asked on January 20, 2009
  53. chem

    sorry for all the questions i have an exam tomoro! but what is intrinsic or intensive are they the same?

    asked on January 7, 2009
  54. chem

    how many protons, nnutrons, atomic mass, mass number, and charge to each of the following have? sodium atom fluorine ion stannic ion for sodium i have protons=11 electrons=11 neutral charge how do i find the number of neutrons cause im pretty sure mass

    asked on January 7, 2009
  55. chemistry

    Calculate the number of C, H, and O atoms in 4.50 g of glucose (C6H12O6), a sugar. help please?

    asked on January 5, 2009
  56. chemistry

    Posted by lyne on Tuesday, March 25, 2008 at 11:44pm. What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second

    asked on March 26, 2008
  57. chemistry

    What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second equilibrium depends upon the amount of [H+] already donated by

    asked on March 25, 2008
  58. math URGENT

    okay i need to find the domain and range of this z(x) = ãx^2 - 100 (everything is in the square root) so i think i found the domain i got [-10,10] but i don't know about the range i solved for x and got stuck here x=ãy^2 + 100 helppp pleaseee :)

    asked on October 29, 2009
  59. chemistry

    mole can be abreviated as mol right??

    asked on September 7, 2009
  60. chemistry

    what ionic compounds could you form from the following? Sodium Calcium Neon Phosphorus Chlorine i have NaCl, CaCl2, Na3P, and Ca3P2 is that all and can neon be used?

    asked on June 6, 2009
  61. CHEMISTRY HELP

    NH3 + HCl --> can someone please finish that?? is it 2H2 + N2 + Cl or something? if so how would i balance it?

    asked on March 26, 2009
  62. chemistry

    If the volume of solute is 6 ml and the volume of the solution is 300 ml, what is the solute's percent by volume? is it solute/solution so % = 6/300 so then would it be % = .02 would i change it to 2%???

    asked on March 8, 2009
  63. Chemistry Web Quest

    How do you recover the dissolved solid in a solution?

    asked on February 13, 2009
  64. chemistry

    we did a lab where we mixed an iron nail with cupric chloride to find the reaction is this the balanced equation... Fe + CuCl2 --> FeCl2 + Cu or would Fe and Cl bond different??

    asked on February 10, 2009
  65. math

    what is the function rule for this figure sides- 3 4 5 6 7 diagonals- 0 2 5 9 15

    asked on February 2, 2009
  66. chemistry

    i did a lab and found that of the products two gases were formed H2 and H2CO3 the question is... What are the tests that will verify the identity of these gases? what is this asking?

    asked on January 20, 2009
  67. chemistry

    What does it mean to say that the ions of an electrolyte behave independently of one another when the electrolyte is dissolved in water? is it something about the compound splitting?

    asked on January 13, 2009
  68. chemistry

    arent the allotropes of carbon diamond buckminsterfullerene(or whatever its called haha) and graphite?

    asked on January 7, 2009
  69. math

    how many mL in .00670 grams of a substance that has a density of 1.96 g/cm3. do you do 1.96g/cm3 divided by .00670 grams to solve for cm3 since cm3 = mL

    asked on January 7, 2009
  70. 9th grade chemistry

    if you have 55.6 grams of nitrate ions in a compound that consists of nitrate ions and plumbous ions, how many grams of the compound do you have? how do i do this problem im completely stuck!?

    asked on December 10, 2008
  71. chem

    DrBob has given you the equation to use: k2 = [H^+][SO4^-]/[HSO4^-] and the values to substitute [H^+] = 0.01 + x [SO4^-2] = x [HSO4^-] = 0.01 - x k2 = 1.2 x 10^-2 you need to substitute these and solve for x. Remember that you are after 0.01+x [H^+] to

    asked on March 26, 2008
  72. math

    Next step, multiply both sides by (.01-x) .012(.01-x)=.01x+x^2 is the binomial x^2 + .002x-1.2x10^-4 what is the next step is the answer -.021 and -.023 for x

    asked on March 26, 2008
  73. chem

    Next step, multiply both sides by (.01-x) .012(.01-x)=.01x+x^2 gather terms, put in standard binomial form, use the quadratic equation, and solve for x. is the standard binomial x^2+.022x-1.2x10^-4

    asked on March 26, 2008
  74. chem

    What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second equilibrium depends upon the amount of [H+] already donated by

    asked on March 26, 2008
  75. math

    i already asked this question for how to divide (x^2 +2x) / 2x-1 i need to find the quoyient not how to simplify it. I need to use the quotient in order to graph an oblique asymptote. can it not be divided?

    asked on November 15, 2009
  76. math

    how would i do (x^2 + 2x) / (2x-1) thanks

    asked on November 15, 2009
  77. math

    what would the graph of this look like xy

    asked on October 24, 2009
  78. microbiology

    what is the common-source outbreak of the H1N1 flu of 2009

    asked on October 15, 2009
  79. math

    ok this is kinda stupid but i totally just confused myself with the simplest thing haha okay when doing the FOIL methed to this equation (-7-y)(-7-y) would it be 49 + 7y + 7y + y^2 or no??

    asked on October 4, 2009
  80. science

    are most petri dishes the same size? if so what would the diameter of one be? i need to find the surface area of a petri dish

    asked on October 4, 2009
  81. ..

    are most petri dishes the same size? if so what would the diameter of one be? i need to find the surface area of a petri dish

    asked on October 4, 2009
  82. microscopes

    When using a light microscope to look att two hairs crossed over each other... Under low power were both hairs in focus at the same time? What about medium power? What does this tell you about the depth of field as you increase magnification. The answer to

    asked on September 27, 2009
  83. Microbiology

    what is the best resolution of our light microscopes the formula should be RP = wavelength/2NA right?? so my question is which wavelength do i put as the denominator

    asked on September 22, 2009
  84. chemistry

    list three ions that are iso-electric with potassium +1 please explain i have no clue

    asked on June 7, 2009
  85. chemistry

    my teacher told me that polar bonds have a difference in elecronegativities of .4-2.1 is that the only way to find if a bond is polar? also how would you find out if the MOLECULE is polar or not? - i think i remember my teacher saying something about

    asked on May 5, 2009
  86. chemistry

    what are structural formulas?? also is this correct hybridization is the setting aside of p orbitals in order to form bonds (pi bonds)

    asked on May 5, 2009
  87. DRBOB

    help with below questions please and thank you

    asked on April 29, 2009
  88. chemistry

    I have to draw the QMM of CL2C2. For the Lewis structure i think that the two C ayoms form a triple bond and the Cl atoms form single bonds. Therefore i think that the central C atom hybridizes into sp. if this is correct, my question is how do i know

    asked on April 29, 2009
  89. chemistry

    when do you need to use the octet rule for lewis structures and when does it not apply i am confused for N2O4 i cant get the rules to work with the structure

    asked on April 20, 2009
  90. chemistry

    Why are all diatomic molecules diatomic molecules linear, regardless of the number of valence electron pairs on the atom? i don't understand this question what is meant by linear?

    asked on April 8, 2009
  91. chemistry

    okay we are drawing bonds and i was wondering how i am supposed to know if you can make a double or triple bond for example for NH2OH why cant i make the bond between N and O triple instead of leaving lone pairs.. thanks

    asked on April 8, 2009
  92. DRBOB

    help below please

    asked on March 19, 2009
  93. chemistry

    Solutions that have large amounts of solute are___ solutions that have small amounts of solute are ___

    asked on February 8, 2009
  94. math

    function rule for tis points- 1 2 3 4 lines- 0 1 3 6 its similar to an earlir one i posted but i still don't quite understand thanks

    asked on February 2, 2009
  95. Dr Bob

    okay and i don't understand what they are asking for for chemical characteristics. i was thinking like density, melting point, and boiling point but arent those physical too?

    asked on January 7, 2009
  96. chemistry

    what are three chemical characteristics and ten physical characteristics so far for physical i have -color -taste -smell -size -luster -shape -texture is this what they are asking for?

    asked on January 7, 2009
  97. c++

    what would the the answer to 55%7 be?

    asked on January 6, 2009
  98. CHEMISTRY HELP

    if you have 55.6 grams of nitrate ions in a compound that consists of nitrate ions and plumbous ions, how many grams of the compound do you have? how do i do this problem im completely stuck!?

    asked on December 10, 2008
  99. 9TH GRADE ALGEBRA

    solve for the variable ã(square root) ãy+6 - ãy = ã2 would i square both sides first? im stuck

    asked on December 8, 2008
  100. 9th grade chemistry

    what is the name for CsF? i had cesium flouride but it's wrong... help?

    asked on December 5, 2008

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