Popular questions and responses by bekah
  1. College Chemistry

    How many milliliters of 0.100 M HNO3 are needed to neutralize the following solutions? A. 45.0 mL of 0.667 M KOH B. 58.5 mL of 0.0100 M Al(OH)3

    asked on October 6, 2011
  2. College Chemistry

    Write formation reactions for the following. (You must include the states of matter for each atom or compound) A. Ca(NO3)2 (s) B. CH3OH (l) C. NaClO4(s)

    asked on October 25, 2011
  3. chem

    given the thermochemical equations, B2O3 + 3H2O -> 3O2 + B2H6 delta h = -2035 kj H2O -> H2O delta h = 44 kj H2 + 1/2O2 -> H2O delta h = -286 kj 2B + 3H2 -> B2H6 delta h = 36 kj what is the delta hf for 4B + 3O2 -> 2B2O3?

    asked on October 17, 2014
  4. art history

    1. the center of the Renaissance 2. written backwards 3. da Vinci apprenticed for this person 4. innovative High Renaissance architect 5. the quintessential Universal man 6. city where da Vinci painted The Last Supper 2. Codex Leiceister 3. Donato Bramante

    asked on June 23, 2014
  5. chem

    consider the chemical reaction, 2Al + 3Cl2 -> 2AlCl3. here, 212.7 g of chlorine can produce a maximum of 266.66 g of AlCl3 (molar mass of Al = 26.98 g and Cl = 35.45 g) true or false

    asked on October 4, 2014
  6. chem

    Consider the chemical reaction, 2Al + 3Cl2 → 2AlCl3. Here, 56 g of Al can produce 415.14 g of AlCl3 (Molar masses: Al = 26.98 g; Cl = 35.45 g). true or false

    asked on October 4, 2014
  7. chemistry

    For each organic compound, determine if it is an alkane, alkene, or alkyne. (No ringed structures and only one multiple bond per structure.) 1. C10H18 - alkyne 2. C15H32 - alkane 3. C20H40 - alkyne 4. C5H10 - alkene 5. C3H6 - alkene 6. C7H16 - alkane I am

    asked on May 6, 2014
  8. chemistry

    Consider a buffer solution consisting of CH3NH3Cl and CH3NH2. Which of the following statements are true concerning this solution? (Ka for CH3NH3+ = 2.3 x 10 -11). 1. A solution consisting of 0.1 M CH3NH3Cl and 0.1 M CH3NH2 would be a more effective buffer

    asked on March 25, 2014
  9. chemistry

    Construct a galvanic (voltaic) cell from the half reactions shown below. Au3+ + 3 e- → Au (s) ξo= 1.420 V Br2 (l) + 2 e-→ 2 Br- (aq) ξo= 1.087 V Calculate the equilibrium constant (K) for this cell. Assume that the temperature is 298K. First,

    asked on May 2, 2014
  10. chem

    balance the reaction using the half reaction method. OsO4 + C2H4 -> Os + CO2 worksheet does not show if it is in a gas and aqueous state.

    asked on December 14, 2014
  11. art history

    1. During the ______, the writings and art of Ancient Greeks were rediscovered. 2. ______ is the study of religious faith, practice and experience. 3. Renaissance thinkers promoted _______, individualism, and secularism. 4. _______ is the idea that people

    asked on June 23, 2014
  12. chemistry

    Match the name or structure with its functional group. Each molecule has only one functional group. My choices are alkane, alcohol, alkyne, carboxylic acid, alkene, aldehyde, ketone, ester, and ether. 1. 2-propanol- alcohol 2. 2-methoxypentane- alkane 3.

    asked on May 10, 2014
  13. chemistry

    The cell shown above is a concentration cell. Both cells contain a copper solution and have copper electrodes. The only driving force for this cell is the difference in the concentration of the copper solutions. The system will react to equalize the

    asked on May 5, 2014
  14. chemistry

    For the reaction, shown below, determine which statements are True and which are False. 3Fe(s) + Cr2O72-(aq) +14H+(aq) → 3Fe2+(aq) + 2Cr3+(aq) + 7H2O(l) ξo=1.77V 1. The oxidizing agent is dichromate (Cr2O72-). 2. The iron half-reaction takes place in an

    asked on May 2, 2014
  15. ap bio

    The number of trophic levels that can be maintained in an ecosystem is limited by: a. a gain in population size b. the loss of potential energy c. the number of individuals in the ecosystem i have chosen a but it is for a grade and i would love some help??

    asked on August 27, 2011
  16. chem

    if the delta h for the reaction A + 2B -> C is 150 kj, delta h for 6A + 12B -> 6C is what?

    asked on October 17, 2014
  17. chem

    Consider the unbalanced chemical reaction Al + Cl2 → AlCl3. How many moles of AlCl3 can be obtained from 360 grams of Cl2? (Molar masses: Cl = 35.45 g/mol, Al = 26.98 g/mol) when i balance the equation i get 2Al+3Cl2->2AlCl3 but when i try to figure out

    asked on October 5, 2014
  18. chem

    In a chemical reaction, A and B reacts to form D. C is the intermediate product of this reaction. Percent yield of the reaction A+B->C is 50% and the percent yield of the reaction C->D is 90%. How many moles of D can be produced when 14 moles of A and B

    asked on October 5, 2014
  19. art history

    1. art enabled new understandings in this field (the protestant reformation) 2. credited with being the founder of Renaissance painting in the Netherlands distance 3. his most famous painting depicts sin and redemption (genre) 4. he brought Germany into

    asked on June 23, 2014
  20. chemistry

    This functional group can be generated by oxidation of an aldehyde. Oxidation is just the reaction with oxygen, but unlike combustion you are not producing carbon dioxide and water.

    asked on May 10, 2014
  21. chemistry

    Use the following pair of reduction half-reactions to design a galvanic cell. Then write in the proper coefficient for each of the species involved in the overall reaction. Water molecules and protons are not shown in the half-reactions, but may be needed

    asked on May 2, 2014
  22. chemistry

    What is the standard entropy of reaction, the standard entropy of reaction, in J/K, for the combustion reaction of ethylene described in the previous questions? The temperature is 298.15K. (Enter your answer as a signed number in scientific notation

    asked on April 24, 2014
  23. chemistry

    Consider the titration of 50.0 mL of 0.200 M HOCl by 0.200 M KOH for the next five questions (Ka for HOCl = 3.5 x 10-8). Calculate the pH after 150.0 mL of KOH has been added.

    asked on March 23, 2014
  24. College Chemistry

    when a 0.702g sample of a mixture of volatile hydrocarbons is burned in a bomb calorimeter with a heat capacity of 4287 J/C, the temperature rises by 4.72 degrees C. How much energy (in kilojoules) is released during combustion?

    asked on October 25, 2011
  25. Algebra

    a man's age today is 2 years more than three times the age his son will be 5 years from now. let a represent the son's age today. Write an expression to represent the man's age today. Then find his age if his son is now 8 years old.

    asked on September 17, 2015
  26. chem

    An award is being plated with pure gold before it its presented to a recipient. If the area of the award is 55.0 cm^3 and will be plated with 3.00 micrometers of Au, what mass of Au will be plated on the award? The density of Au is 19.3 g/cm^3.

    asked on December 14, 2014
  27. chem

    When Mg reacts with HCl, it produces MgCl2 and H2(g). If 2.34 g of Mg react, how much MgCl2 is produced (in grams)?

    asked on December 13, 2014
  28. chem

    1.70 L of 0.550 M H2O2 reacts according to the following reaction. 2H2O2(aq) -> 2H2O(l) + O2(g) How much H2O is formed? (molar mass of H = 1.00 g/mol O = 16.0 g/mol)

    asked on November 15, 2014
  29. chem

    A 20.0% (w/w) aqueous solution of NaOH has a density of 1.125 g/cm^3. What is the molarity (M) of this solution?

    asked on November 14, 2014
  30. chem

    the work done by a gas when it expands to 96 L is 4100 J. if the external pressure is 2.0 atm, determine the initial volume of the gas.

    asked on October 16, 2014
  31. chem

    A sample of gas has a volume of 50 mL and an initial temperature of 380 K. The temperature must be changed to _____ K in order to halve the volume. Assume constant pressure and amount for the gas.

    asked on October 10, 2014
  32. chem

    H2 stored in a 50.0 L container has a pressure of 500.0 torr. O2 stored in a 25.0 L container has a pressure of 800.0 torr. If both these gases are released together to be stored in a 100.0 L container, what is the total pressure in the 100.0 L container?

    asked on October 10, 2014
  33. chem

    the molar mass of NaCl is 58.45g. How many molecules does a gram of NaCl contain?

    asked on October 4, 2014
  34. chem

    how many moles of HCl will be produced when 30g of H2O are reacted according to the chemical equation 2AlCl3 + 3H2O -> Al2O3 + 6HCl? (molar masses are H2o=18.015g and HCl=36>46g)

    asked on October 4, 2014
  35. chem

    which of the following ions are formed when AgNO3 dissociates? a. O2- b. N3- c. AgN2- d. NO3- e. N2-

    asked on September 26, 2014
  36. chem

    A typical dose of a radioactive sample is 27.0 mCi. How long does it take for the activity to reduce to 0.100 mCi? The half life of the sample is 211,000 y.

    asked on September 19, 2014
  37. chem

    The half life of Am-241 is 432 y. If 2.00 g of Am-241 is present in a sample, what mass of Am-241 is present after 1000.0 y?

    asked on September 19, 2014
  38. chem

    If a radioactive sample has an activity of 8.33 Bq, how many disintegrations per second are occurring?

    asked on September 19, 2014
  39. chem

    A sample of radon has an activity of 80,000 Bq. If the half-life of radon is 15 h, how long before the sample's activity is 5,000 Bq?

    asked on September 19, 2014
  40. chem

    How long does it take for 10.0 g of a radioactive isotope to decay to 1.25 g if its half-life is 17.0 d?

    asked on September 19, 2014
  41. art history

    1. Art enabled new understandings in this field 2. Credited with being the founder of Renaissance painting in the Netherlands 3. his most famous painting depicts sin and redemptionhe 4. brought Germany into the mainstream of Renaissance art 5. objects

    asked on June 23, 2014
  42. chemistry

    This type of functional group is often sweet smelling and may be used as a fragrance. When it reacts with water it will produce a carboxylic acid and an alcohol. I chose ester but it is wrong

    asked on May 10, 2014
  43. chemistry

    How many grams of copper will be deposited at the cathode of an electrolytic cell if a current of 680.0 mA is run through a 2.5 M solution of copper sulfate for 20.0 minutes?

    asked on May 5, 2014
  44. chemistry

    Consider the following standard reduction potentials of some commonly used metals: ξo (V) Au3+ (aq) + 3 e- → Au (s) +1.50 Ag+ (aq) + e- → Ag (s) +0.80 Cu2+ (aq) + 2e- → Cu (s) +0.34 Fe3+ (aq) + 3e- → Fe (s) -0.036V Al3+ (aq) + 3e- → Al (s) -1.66

    asked on May 2, 2014
  45. chemistry

    Under standard conditions, the Gibbs free energy of the reactants G,std(reactants) in a reaction in the gas phase is 232.94 kJ and the Gibbs free energy of the products G,std(products) is 211.56 kJ. Calculate the value of the equilibrium constant for this

    asked on April 28, 2014
  46. chemistry

    Adding a complex ion forming species to a solution will increase the solubility of a slightly soluble species. Calculate the Molar solubility (s) of AgI in a 1.75 M ammonia solution. The Ksp for AgI is 8.3 x 10-17 and the Kf for Ag(NH3)2+ is 1.5 x 107. I

    asked on April 14, 2014
  47. chemistry

    A 1.0 L solution has 10.00 grams of CaCl2 dissolved in it. What is the Molar solubility of AgCl in this same solution? The Ksp for AgCl is 1.6 x 10-10 at this temperature. Hint: watch out for the common ion again.

    asked on April 12, 2014
  48. chemistry

    It is possible to manipulate the solubility of some compounds through pH adjustments. What is the appropriate pH that will yield a Molar solubility for Mg(OH)2 of 2.51 x 10-8? The Ksp for Mg(OH)2 is 1.2 x 10-11. (Hint: you may assume the concentration of

    asked on April 12, 2014
  49. chemistry

    My original sample of mixed salt had a mass of 8.9 grams. After heating the mixture in the crucible and weighing it multiple times my final mass of salt ended up being 4.9. How many moles of oxygen were driven off? Lost on how to do this been a while since

    asked on April 1, 2014
  50. chemistry

    If my original sample contained 7.1 grams of potassium chlorate. How many moles of oxygen gas would I expect to have evolved? Hint: Convert grams to moles of potassium chlorate, then use the mole ratio in the balanced equation. Balance this equation KClO3

    asked on April 1, 2014
  51. chemistry

    A 1.0 M acetic acid solution (CH3COOH, pKa = 4.7) is neutralized by dissolving NaOH(s) (a strong base) in the solution. Estimate the pH at the equivalence point of the neutralization process: 4.7 7.0 9.3 Which one of the following statements best explains

    asked on March 31, 2014
  52. chemistry

    Select only the True statements about buffer systems. Select all that are True. 1. Starting with NH3(aq) and adding a small amount of HCl(aq) will make a buffered solution. 2. The blood buffer, among other things, is supported by carbonic acid and its

    asked on March 28, 2014
  53. chemistry

    enzoic acid is a weak monoprotic acid with Ka = 6.5×10-5 M. NaOH(s) was gradually added to 1.00 L of 8.66×10-2 M benzoic acid. 1. Calculate the pH of the solution before the addition of the base. 2. Calculate the pH of the solution after the addition of

    asked on March 25, 2014
  54. math


    asked on February 13, 2014
  55. physics

    Joe stands on a bridge kicking stones into the water below. If he kicks a stone with a horizontal velocity of 3.10 m/s, and it lands in the water a horizontal distance of 6.60 m from where Joe is standing, what is the height of the bridge? Enter m as unit.

    asked on December 5, 2011
  56. English

    is this true:Introductory participial phrases and adverb clauses are set off from main clauses by commas.

    asked on October 27, 2011
  57. College Chemistry

    Calculate the concentrations of the following solutions, assuming the volumes are exact measurements: a. 18.64g of sodium hydroxide in 350mL of solution b. 8.97mL of 18M hydrochloric acid in 250mL of solution

    asked on October 4, 2011
  58. College Chemistry

    Zinc, copper, lead, and mercury ions are toxic to Atlantic salmon at concentrations of 6.42 times 10 to the -2 mM, 7.16 times 10 to the -3 mM, 0.965 mM, and 5.00 times 10 to the -2 mM, respectively. What are the corresponding concentration is milligrams

    asked on October 2, 2011
  59. College Chemistry

    How many grams of solute are needed to prepare each of the following solutions? A. 1.000 L of 0.180 M NaCl B. 250.0 mL of 0.150 M CuSO4 C. 500.00 mL of 0.355 M CH3OH

    asked on October 2, 2011
  60. Chemistry

    Iron (II) ions can be precipitated from the following reaction: 4Fe(OH)+(aq) + 4OH-(aq) + O2(g) + 2H2O(l) --> 4Fe(OH)3(s) How many grams of oxygen gas will be needed to precipitate the iron contained in 125mL of 0.085M Fe(OH)+ solution?

    asked on September 28, 2011
  61. chemistry

    What is the concentration, in units of molarity, of a 350 mL solution containing 0.298 moles of sodium chloride in water?

    asked on September 27, 2011
  62. chemistry

    A 8.00 M solution of hydrochloric acid is provided. You need to make 25.0 mL of a 0.490 M HCl solution. What volume, in mL, of the 8.00 M solution should you use?

    asked on September 27, 2011
  63. calc

    can you just show me how to set this up? or a formula that could help? im confused. The length of a rectangle is increasing at 3 ft/min and the width is decreasing at 2 ft/min. When the length is 50 ft and the width is 20 ft, at what rate is the rectangle

    asked on January 2, 2011
  64. biology

    What is the variable being tested in an experiment called?

    asked on December 14, 2010
  1. History

    I already did this and the correct answer is C.

    posted on March 30, 2019
  2. Algebra

    What in the world...

    posted on September 25, 2017
  3. American Government

    The correct answers are: 1.) C 2.) A 3.) C 4.) D 5.) A 6.) B 7.) A 8.) B

    posted on March 21, 2017
  4. Calc

    144/24 = 6

    posted on February 21, 2017
  5. Chemistry

    A trick is to just look for the element in the equation that is paired on one side, but not on the other. This being said, the following answers are correct. Redox: 2CO+O2 = 2CO2 Zn+CuCl2 = ZnCl2+Cu Non-Redox: SO3+H2O = H2SO4 HCl+NaOH = H2O +NaCl

    posted on November 8, 2016
  6. chemistry

    They cannot explode like a nuclear bomb, that's for sure.

    posted on November 6, 2016
  7. Comm Tech

    A and D are right.

    posted on October 12, 2016
  8. Algebra2

    A is the correct answer.

    posted on September 30, 2016
  9. chem

    this is what was on my worksheet

    posted on December 14, 2014
  10. chem

    i have know idea how to even figure it out with just volume 1 and temp 1. i have tried multiple ways with the equation but not getting anywhere

    posted on October 11, 2014
  11. art history

    Thanks I figured it out. Thanks for all your help tonight.

    posted on June 23, 2014
  12. art history

    You told me 1 and 3 but thank you so much.

    posted on June 23, 2014
  13. art history

    Number 2 is Albert durer

    posted on June 23, 2014
  14. art history

    3. Humanism 4. theology 1. Renaissance 5. Italy Printing press Protestant 2. Secularism 9.Paper relief Mapmaking

    posted on June 23, 2014
  15. art history

    Oops that's Albert durer

    posted on June 23, 2014
  16. art history

    I have 7 also

    posted on June 23, 2014
  17. art history

    This is different questions. I never got answers to these. I have 1 through 4. I need help on the rest.

    posted on June 23, 2014
  18. art history

    Thanks I have all except 3 and 4, can you help me with those please?

    posted on June 23, 2014
  19. art history

    Distance Parallel Vanishing Hieronymus bosch Jan van Eyck Albrecht Düre Mathematical polyptch

    posted on June 23, 2014
  20. chemistry

    the answers i have tried are F,F,T,T and F,F,T,F

    posted on May 5, 2014
  21. chemistry

    i am using dG=dH-tdS and i have tried dG-dH/T,dG/dH+T,dG/dH-T. My answers are -1.33,-1.0E3, -1.01E2

    posted on April 24, 2014
  22. chemistry

    i figured it out

    posted on April 12, 2014
  23. chemistry

    Solubility and Precipitation: 1. Alkali Metal Cations, ammonium cations= Soluble. 2. Nitrate Anions, Acetate Anions= Soluble. 3. Halogen anions= Soluble...except: Ag+, Cu+, Hg2 +2, and Pb+2. 4. Sulfate Anions= Soluble...except: Ba +2, Ca+2, Hg2 +2, Pb+2,

    posted on October 4, 2011
  24. college math

    Step 1: Eric = 1/2 of Dans; Eric + Dan = 18 Step 2: 12 + 6 = 18 Step 3: Eric has to be 6 because half of 12 is 6 and when you add them together you 18. Step 4: Equation- Part A: D = 12; E = 1/2D; T= 18. Equation- Part B: E + D = T so... 1/2D + D = 18!!!!

    posted on September 27, 2011
  25. calc

    thank you so much!!!!

    posted on January 2, 2011
  26. math

    R because the others all have set limitations. R is the only one that makes sense! Since numbers can go on forever that means numbers greater than 18 would be infinite!

    posted on December 14, 2010
  27. algebra

    -72/14*14/-72 (cross multiply) ?

    posted on December 14, 2010
  28. Geometry

    the info of about the circle is irrelevent. Since the triangel is isosceles than that means another side of it is 4r. Find the missing side then use the area of a triangle formula!

    posted on December 14, 2010
  29. ponctuation, mechanisme, and writing

    First off, it is one thing to ask for assistance because you do not understand something. It is a completely different thing for someone to give you all of the answers. It really is your loss though, because instead of getting the reasoning why and

    posted on December 9, 2009