1. Chemistry

    What is the vapor pressure of the solvent in an aqueous solution at 25◦C of 0.29 m (molality) urea(CO(NH2)2), a nonelectrolyte? The vapor pressure of water at 25◦C is 23.76 Torr. Answer in units of Tor I want to use the mole fraction and multiply it by

    asked by ND on February 2, 2011
  2. chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the

    asked by thuy on February 22, 2008
  3. Chemistry

    A volume of 5oo ml of potassium sodium tartrate solution S1 of c1=0.21mol/l is to prepared. Determine the mass of hydrated potassium sodium tartrate of formula KNaC4H4O6.4H2O needed for this preparation .(molar atomic masses : H=1;C=12;O=16;Na=23;K=39)

    asked by Roro on February 23, 2014
  4. Chen=mistry

    Sodium metal reacts violently with water to form NaOH and release hydrogen gas. Suppose that 3.00 g of Na reacts completely with 3.00 L of water and the final volume of the system is 3 L. What is the molarity M of the NaOH Solution formed by the reaction?

    asked by Janet on May 1, 2013
  5. Chem-Diprotic Acid

    Ascorbic Acid is an organic diprotic acid, H2A, that is found in many natural materials. KA1=7.94x10^-5 and KA2=1.62x10^-12. If you start with a 0.75 M solution of H2A, what is the concentration of ALL species in the solition at ph=3.8? I have no idea how

    asked by Matt on December 7, 2014
  6. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the

    asked by Anonymous on June 29, 2008
  7. Chemistry

    Raoult's Law and Ionic or Organic Solutions At 55.0 C, what is the vapor pressure of a solution prepared by dissolving 62.8 g of LiF in 247 g of water? The vapor pressure of water at 55.0 C is 118 mmHg. Assume complete dissociation of the solute.

    asked by Saira on January 25, 2010
  8. maths

    A car travels 40 miles per gallon of petrol. How many kilometres can it travel on 5 gallons of petrol? (From a KS2 CGP SATs question book). The solution in the book says 40/5 = 8 8x8=64 64x 5 = 320Km I get the 64x5 =320Km, but not the first bit. Can anyone

    asked by Anna on March 20, 2016
  9. algebra

    Solve. Simplify your answer. Type an exact answer using radicals as needed. y^2 + 31 = 12y Solution y = {8.236067978, 3.763932022} 1. y =(12-√20)/2=6-√ 5 = 3.764 2. y =(12+√20)/2=6+√ 5 = 8.236 Which would be the correct way to answer this equation,

    asked by slomo on February 3, 2015
  10. chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN¡V was 0.00050 M, the

    asked by Gloria on April 10, 2008
  11. chem

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, what is the

    asked by anonymous on April 10, 2008
  12. Chemistry

    A volume of 5oo ml of potassium sodium tartrate solution S1 of c1=0.21mol/l is to prepared. Determine the mass of hydrated potassium sodium tartrate of formula KNaC4H4O6.4H2O needed for this preparation .(molar atomic masses : H=1;C=12;O=16;Na=23;K=39)

    asked by Roro on February 22, 2014
  13. Chemistry

    A compound is known to be a cesium halide, CsX. If 3.00 grams of the salt is dissolved in exactly 100.0 grams of water, the solution freezes at -0.735°C. What is the chemical formula for the salt? i know it would be -0.735= -1.86 * m m= 3g/ X g/mol/kg

    asked by Susy on February 20, 2014
  14. Chemistry

    Use the balanced equation for the reaction of lithium oxide with water: Li2O(s) + H2O(g) --> 2LiOH(s) to determine how many grams of H2O can be removed from the air by 250g of Li2O. Show your step-by-step solution with unit conversions.

    asked by Jane on September 26, 2018
  15. Chemistry

    If the 50.00mL sample from problem 3 above was titrated with EDTA,what volume of a 0.00420 M EDTA solution would be needed to reach the endpoint? (Your answer should be given in milliliters.) (Problem 3 found that .0000625 moles of calcium carbonate were

    asked by Alex on November 13, 2015
  16. chem

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, the

    asked by Adam on April 11, 2010
  17. chemistry 11 grade

    A piece of iron wire weighs 2.225g. It is dissolved in acid, which oxidizes the iron to iron(II), and made up to 250 mL. A 25mL sample required 31.0 mL of a 0.0185mol/L solution of potassium dichromate. Calculate the percentage of iron in the wire.

    asked by Farah on January 2, 2011
  18. chemistry

    How many electrons are transferred in the reaction of hydrogen peroxide with iron (II) ion in acidic solution to form iron (III) ion and water? i'm not sure if iposted this already... sorry if i did :) Fe^+2 ==> Fe^+3 + e 2e + 2H^+ + H2O2 ==> 2H2O Multiply

    asked by Christine on April 22, 2007
  19. Chemistry

    What is the pH of the solution created by combining 2.70 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? with 8.00 mL of the 0.10 M HC2H3O2(aq)? What are the pH values if you take into account that the 8.00 mL of 0.10 M Acid was first diluted

    asked by Ashley on May 3, 2010
  20. Physics

    A capacitor is made from two 1.2 cm diameter coins separated by a 0.18 mm thick piece of paper (K = 3.7). A 6 V battery is connected to the capacitor. How much charge is on each coin? My solution: C= K * Permitivity * A/d = q/v I solved for q and got 1.2 X

    asked by BLESSED on February 6, 2008
  21. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the

    asked by John on June 20, 2011
  22. college chemistry

    Calculate the [CH3NH3+] of a 7.02×10-3 M solution of the weak base CH3NH2 (make an approximate calculation assuming that initial concentration is equal to the equilibrium concentration). Round your answer to 3 significant digits. CH3NH2 + H2O = CH3NH3+ +

    asked by sparkle on October 26, 2010
  23. chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, what is the

    asked by Amy on April 8, 2008
  24. 12th grade chemistry

    A piece of iron wire weighs 2.225g. It is dissolved in acid, which oxidizes the iron to iron(II), and made up to 250 mL. A 25mL sample required 31.0 mL of a 0.0185mol/L solution of potassium dichromate. Calculate the percentage of iron in the wire.

    asked by jerry on November 10, 2008
  25. Biochemistry

    A buffer solution is prepared by mixing 2.50 mL of 2.00M sodium acetate with 3.30mL of 0.500M HCl and diluting the buffer with water to a final volume of 500.0mL. pK acetic acid: 4.76 what is ph of buffer? what is final concentration of buffer?

    asked by Maria on February 4, 2014
  26. chem

    A student weighs out a 13.7 g sample of Cr(NO3)3, transfers it to a 300 mL volumetric flask, adds enough water to dissolve it and then adds water to the 300 mL tic mark. What is the molarity of chromium(III) nitrate in the resulting solution?

    asked by dan johnson on April 10, 2011
  27. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the

    asked by Chem help on August 10, 2008
  28. chemistry

    What will be the molarity of 335 ml of solutions containing 1.02 g of magnesium perchlorate. Here what i think divide 335/1.02 to get answer but i am not sure. Question 2:) how many ml of solute will be dissolved in a 435ml of 5.4%v/v of hci solution. I am

    asked by kody on July 18, 2014
  29. Algebra

    You are taking a science course in which there will be four tests, each worth 100 points. You have scores of 94,100, and 92 on the first three tests. You must make a total of 360 in order to get an A. What scores on the last test will give you an A? The

    asked by Spacegazing on March 7, 2014
  30. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.530. If a trial's absorbance is measured to be 0.150 and its initial concentration of SCN– was 0.00070 M, the

    asked by Sam on April 9, 2008
  31. Chemistry

    so i had to calculate the pH of a 100ml solution of .10M acetic acid (ka=1.8x10(-5) I came out to 2.87. But then, they want the pH if 50ml HCL is added. So i thought...Ka = x2/.15M, therefore the square root of .15M x 1.8x10(-5) = .00164(concentration). So

    asked by Kevin on October 20, 2011
  32. Chemistry

    What is the pH of the solution created by combining 2.70 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? with 8.00 mL of the 0.10 M HC2H3O2(aq)? What are the pH values if you take into account that the 8.00 mL of 0.10 M Acid was first diluted

    asked by Ashley on May 3, 2010
  33. physical chemistry

    1000 ml of oxygen at ntp passed through siemens ozoniser when the resulting volume was 888 ml at ntp .quantity of ozonised oxygen is passed through excess of potassium iodide solution calculate weight of iodine liberated?

    asked by Anonymous on April 13, 2013
  34. Science

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the

    asked by Bobby on November 3, 2008
  35. Chemistry

    What is the pH of a 1.0E-8 M solution of HCl? Please note that you cannot simply add the contribution of H+ ions from the autoproteolysis of water and the contribution from the dissociation of HCl. You will need to use the quadratic equation to solve this

    asked by Joel on September 3, 2010
  36. chemistry

    This refers to your archive question in 2014 Oct 30 at 4.58 posted by Ruzzle and replied by DrBob222. Small query on the solution , which states 1/6 of D atoms will go to form D2O18. Isn't it 2/6 since out of all 6 D atoms 2 is required to form D2O18.

    asked by senaka on March 13, 2017
  37. Pre-calculus (trigonmetry)

    The Bermuda Triangle is an unmarked area in the Atlantic Ocean where there have been reports of unexplained disappearances of boats and planes and problems with radio communications. The triangle is an isosceles triangle with vertices at Miami, Florida,

    asked by Lucina on March 3, 2015
  38. Chemistry

    If 20mL of a 0.100 M NaOH solution are required to titrate 0.25 grams of an unknown acid, what is the equivalent mass of the acid? If the acid actually contains 3 moles of H+ per mole of acid what is the molecular mass of the acid?

    asked by Linda on February 4, 2014
  39. Art

    in modern printing technology what important type of plate is created a nickel salt solution? Copper plate •• Printing plate Master plate Money plate Correct this if you can

    asked by Tj on February 26, 2016
  40. Chemistry

    Which solution will have the lowest pH? a. 0.10 M HClO2, pKa = 1.96 b. 0.10 M HCN, pKa = 9.21 c. 0.10 M HF, pKa = 3.19 d. 0.10 M HClO, pKa = 7.538 e. 0.00010 M HCl Does the lower the pka stronger the acid, means the lower the ph, so the answer is A?

    asked by Anonymous on November 29, 2015
  41. #2

    How are these stressors impacting Michael’s or Jennifer’s self-concepts and self-esteem? Each individual perceives these stressors differently. In Michael’s case, his self-concept is based on feelings and interpersonal needs. He might feel that

    asked by rose - Ms. Sue on June 5, 2008
  42. Psychology

    Sources of stress do not automatically cause stress-related problems. Moderators of stress, which can include our personal strengths, might mean that we can have a healthier and more productive life in spite of life's challenges, or maybe even because of

    asked by william on October 28, 2012
  43. Geography (Ms. Sue)

    1). What are the steps in slash-and burn farming? 2). What are some of the problems of cities in the region? My answers to these questions are the following: 1). The steps of slash-and-burn farming are: first, to cut trees, brush, and grasses to clear a

    asked by Anonymous on September 20, 2013
  44. chemistry

    how many grams of H2 (g) are produced by the reaction of 1.35 g Al with 75.0 mL of 3.44 M HCl Here is the way to do most of these stoichiometry/limiting reagent type problems. Step 1. Write a balanced chemical equation. 2Al + 6HCl ==? 3H2 + 2AlCl3 Step 2.

    asked by brian on September 24, 2006
  45. HW CHECK

    What is the verb in the following sentence? (only one answer) 1. Many people believe that the economy is not the worst problem in America. a. Many b. believe c. is d. is not e. in What is the subject in the following sentence? (may be one or more) 2. Her

    asked by Anonymous on October 26, 2011
  46. Quick english check

    Use adapt, alleviate, anecdote, attributed, diminutive, distinct, endowed, enhance, facilitating, incantation, irony, linguistic, mitigates, ponderous, restitution, and resuscitate to put in the correct sentence. Please correct me if I’m wrong! On

    asked by Anonyomous on October 7, 2015
  47. Chemistry------DrBobb..

    Lead metal is added to 0.140 Cr^3+(aq). Pb(s)+ 2Cr^3(aq) Pb^2+(aq)+2Cr^2+(aq) KC=3.2*10^{-10} A. What is Pb^2+ when equilibrium is established in the reaction? B. What is Cr^2+ when equilibrium is established in the reaction? C. What is Cr^3+ when

    asked by Saira on February 7, 2009
  48. Probablity

    Samir had prepared the problem tests for Stages 1 to 5 of Geometry and Combinatorics for next week but forgot to label which test was for which stage. Since Samir didn't label them, the computer assigned them labels 1 through 5 randomly, with each label

    asked by Mathslover on May 14, 2013
  49. pre-calculus

    R(x)=x^2+x-6 ________ x-3 1. find the domain and y-intercepts 2. find the x-intercepts 3. find the real solution of the equation 4. find the horizontal or oblique asymptotes 5. find the x-axis 6. plot the points

    asked by ladybug on September 29, 2012
  50. Chemistry

    If 32.3 grams of KCl are dissolved in 192 grams of water, what is the concentration of the solution in percent by mass? 5.94% KCl 8.55% KCl 14.4% KCl 16.8% KCl Can someone explain this to me? I don't want the answer I just want to know how to find it.

    asked by Acasia on February 20, 2017
  51. english

    summarize into a paragraph. Establishing bilingual education programs was a reaction to these problems. It was an attempt to bring education to students who had special needs. Bilingual education tries to meet students at their level rather than the level

    asked by derrius on March 24, 2010
  52. english

    (Please check my essay for me) thank you very much. Subject: Oil and Gas Prices Introduction: The economy is influenced by many factors that determine its surplus or deficit. Throughout the last several decades, we have seen the world’s dependency on Oil

    asked by rose on March 20, 2008
  53. algebra

    I am having a lot of difficulty trying to figure out how to put two math (word problems) questions into an expression. Can someone help me, I can do the rest from there. An explanation on the math formula would be great too. here's the two questions. 1.

    asked by Rick on May 15, 2010
  54. ethics

    How do you think slavery influenced the evolution of both Black and White America today? Think about the degradation of one person "owning" another human being. The slave owner assumes s/he is superior. The slave assumes s/he is inferior. For many people

    asked by michael on April 10, 2007
  55. chemistry

    consider a crystallization of sulfanilamide in which 10 mL of hot 95% ethyl alcohol is added to 0.10 g of impure sulfanimide. after the solid has dissolved, the solution is cooled to room temp. and then placed into an ice-water bath. no crystals for, even

    asked by BOB on October 7, 2008
  56. Chemistry

    A mixture of ethane and ethene occupied 35.5 L at 1.000 bar and 405 K. This mixture reacted completely with 110.3 g of O2 to produce CO2 and H2O. What was the composition of the original mixture? Assume ideal gas behavior Im pretty sure i use dalton's law

    asked by Drew on September 19, 2012
  57. grammar

    Need to identify five adverbs in this paragraph. I think I am correct but would like a second opinion. Thanks for your thoughts. LITTLE FOCKERS is the “continued” (adverb) antics of Greg and Pam Focker (Ben Stiller and Teri Polo) who “now” (adverb)

    asked by Jack on January 13, 2011
  58. physics (mirror)

    a diverging mirror of 52.0 focal lenght produces a virtual image of 26.0cm from the mirror. how far from the mirror should the object be placed? solution f=-52.0cm, v=-26.0cm 1/u + 1/v = 1/f rearranging the terms 1/u = 1/f - 1/v substituting the values of

    asked by Matrix School 2 on July 28, 2009
  59. Algebra 2

    James sold magazine subscriptions with three prices: $26, $19, $ 23. He sold 3 fewer of the $26 subscriptions than of the $19 subscriptions and sold a total of 32 subscriptions. If his total of sales amounted to $716, how many $23 subscriptions did James

    asked by Kat on October 27, 2011
  60. Algebra 2

    James sold magazine subscriptions with three prices: $26, $19, $ 23. He sold 3 fewer of the $26 subscriptions than of the $19 subscriptions and sold a total of 32 subscriptions. If his total of sales amounted to $716, how many $23 subscriptions did James

    asked by Kat on October 27, 2011
  61. chemistry

    Okay so I did this problem, but it seems wrong? I put the answers I got... Determine the pH of the following tiration at each of the points indicated. A 71.7 mL solution of 0.182 M NaOH is titrated with 0.2086 M HCL. 1.) initial pH= is it 7.86 or 8.51? 2.)

    asked by help meeee pleaaseee on October 9, 2011
  62. Biochem

    Desribe the preparation of 2.00 L of 0.100M pH 9.00 glycine starting with the sodium chloride salt of zwitterionic glycinhe and 1.00M NaOh. If a reaction that generated 2.00 mmoles of base were carried out in 100 mL of the above buffer, what would be the

    asked by Sandra on September 13, 2011
  63. Basic Communications

    I'm trying to add more details to this paragraph on my assignment: Lastly, Temporary Marriage Licenses are not a good solution to high divorce rates because couples in a boyfriend-girlfriend relationship should look into all the responsibilities that the

    asked by Alex L. on December 4, 2011
  64. Chemistry (concentration)

    H2SO4(aq) + 2LiOH(aq) → Li2SO4(aq) + 2H2O(l) 3.2 moles of LiOH enter the reaction and are fully consumed. The molar mass of Li2SO4 is 110 g/mol. The final aqueous solution has a volume of 4.0 L. What is the final concentration of Li2SO4 in g/L? 44

    asked by Summer on April 11, 2018
  65. AP Chemistry- please help!

    Glycerol (a non-electrolyte that can be used as antifreeze and coolant in a car radiator) has a density of 1.261 g/mL and a molecular weight of 92 g/mol. If 111 mL of glycerol are mixed with 5.1 kg of water, by how much would the boiling point of the

    asked by Anonymous on April 5, 2018
  66. AP Chemistry- please help!

    Glycerol (a non-electrolyte that can be used as antifreeze and coolant in a car radiator) has a density of 1.261 g/mL and a molecular weight of 92 g/mol. If 111 mL of glycerol are mixed with 5.1 kg of water, by how much would the boiling point of the

    asked by Kayla on April 5, 2018
  67. Intermediate Algebra

    Andrews factored expressions -6x63+9x^2-3x as -3x(2x^2-3x-1). But when Melissa applied the distrubutive law and multiplied out -3x(2x62-3x-1) she got -6x^3+9x^2+3x;thus Andrews solution does not appear to check. Why is that? Please help Andrews to

    asked by ladybug on June 13, 2012
  68. Chem (electron transfer)

    KMnO4 + HCl → MnCl2 + Cl2 + H2O + KCl If the reaction occurs in an acidic solution where water and H+ ions are added to the half-reactions to balance the overall reaction, how many electrons are transferred in the balanced reduction half-reaction? The

    asked by Summer on April 2, 2018
  69. Chemistry

    Would your calculated Ksp value be greater, less, or the same, if the following occurred, please explain your reasoning. a. The CaSO4 was not saturated b. You accurately measured 20.00 mL instead of 25.00 mL using a pipet c. The CaSO4 solution contained

    asked by sea lively on August 14, 2018
  70. math

    Please show all of your work in the space below. Please present and organized and complete solution. A garden will be made up of a parallelogram, a rectangle and a triangle. The garden must have an area of 500m square. Draw two possible gardens. Determine

    asked by jhon on November 22, 2013
  71. Chemistry

    A student was given a 2.45 g of impure potassium sulfate (K2SO4) sample. He dissolved this sample in 100 mL of water first and then added some barium chloride (BaCl2) solution. A 2.15 g of BaSO4 precipitate was obtained at the end of the reaction. What is

    asked by Anonymous on November 22, 2014
  72. Chemistry

    An aqueous solution of ammonium nitrate NH4NO2 decomposeds when heated to give off nitrogen. This reaction may be used to prepare pure nitrogen. How many grams of ammonium nitrite must have reacted if 3.75dm^3 of nitrogen gas was collected over water at 26

    asked by Lauren on October 23, 2007
  73. chemistry

    an aqueous solution contains 2 solutes A&B.A is soluble in hexane,B is not.Hexane is liquid at rom temperature and does not mix with water.The density of hexane at room temperature is 0.7g/dm3.Describe giving full practical details how you would produce a

    asked by Natalia on February 11, 2010
  74. Health (Ms. Sue)

    1. Identify ways that you can tell if a relationship is healthy. Discuss what you can do if the relationship isn't healthy. A: You can tell if a relationship is healthy by asking yourself a series of questions, such as whether this friendship brings out

    asked by Anonymous on December 7, 2013
  75. Calculus

    Below are the 5 problems which I had trouble in. I can't seem to get the answer in the back of the book. Thanks for the help! lim (theta-pi/2)sec(theta) theta->pi/2 Answer: -1 I am not sure what to do here. lim (tan(theta))^(theta) theta->0+ Answer:1

    asked by Anonymous on February 17, 2008
  76. sociology

    what problems do women face in trying to achieve equal relationship with men in the family? In what culture? In what era? You need a more specific question to come up with a decent answer. The first site will give you a large number of sites on US gender

    asked by pallavi on June 8, 2007
  77. Chemistry

    Sometimes the basicity of a solution is reported using pOH (pOH = -log[OH-]). What is the a. [OH-] if pOH = 1.90 b. [H3O+] if pOH = 12.94 c. pH if pOH = 9.70

    asked by chelsey on March 11, 2014
  78. math

    Please help, 1) How do you solve 2017^2017 without a calculator? 2) What is the last digit of the solution to this problem: 2017^(2017^2017)? Thank you!

    asked by Onet on March 10, 2017
  79. chemistry

    Sometimes the basicity of a solution is reported using pOH (pOH = -log[OH-]). What is the a. [OH-] if pOH = 1.90 b. [H3O+] if pOH = 12.94 c. pH if pOH = 9.70

    asked by amber on March 18, 2014
  80. Chemistry

    Q1. The blood volume in a cancer patient was measured by injecting 5.0 mL of Na2SO4(aq) labeled with 35S (t1/2 = 87.4 d). The activity of the sample was 300 µCi. After 22 min, 12.9 mL of blood was withdrawn from the man and the activity of that sample was

    asked by Trixie on April 16, 2010
  81. math

    Relative humidities (represented by RH below) of less than 51% cause problems in growing crops. The Saskatoon region is a prime wheat-growing area. The mean RH in Saskatoon is 59% in July, with a standard deviation of 8%. The RH for the days in July forms

    asked by ken on March 28, 2010
  82. Business

    what role do managers play in helping their organization become successful? How might this impact you as a employer? Managers play a big role in helping their organization become successful. The manager makes sure that everything is going well and that

    asked by Anonymous on February 27, 2007
  83. social studies

    1.Israel is much smaller in land area than Saudi Arabia, but it is the center of more conflict over land ownership.Why do you think this is the case? Because most people live along the coastal plain in Israel and the eastern interior is dry and includes

    asked by Jayce on April 2, 2013
  84. Math

    An external sinusoidal force is applied to an oscillating system which can be modelled by a model spring and a damper. The general solution of the equation of the motion is given by, x = 5 + 3.071cos(2πt – β) + 3.14exp(-7.96t) cos(αt + φ) where α,

    asked by Darren on September 3, 2012
  85. Conductivity

    Complete the table below: For each of the following sets pick the compound with the highest conductivity in a 1 M aqueous solution. (Enter the number at the top of the column containing the correct answer.) 1 2 3 Answers a HCl HC2H3O2 H2PO4– b KNO3

    asked by Helen on January 12, 2011
  86. chem

    Assuming the volumes are additive, what is the [Cl-]solution obtained by mixing 210mL of 0.600M KCl and 630ml of 0.385M MgCl2 ? Responses chemistry - bobpursley, Friday, September 19, 2008 at 4:20pm You have to assume each chloride is soluble. How many Cl

    asked by jay on September 20, 2008
  87. Geometry

    I need help solving for the height of a trapezoid and finding the correct final answer for a semi circle (a half circle).In area form Here's what I have so far: Trapezoid Formula: 1/2(b1+b2)h My Answer:1/2(5+15)=10 (My bases are 5 and 15) I need help

    asked by GGGGGGGGGGGG-Geometry on April 21, 2017
  88. english

    A poem in the 1930-1960's that relates to "How To Kill A Mockingbird"?I have to write a five paragraph paper discussing how the poem relates to one of the following from To Kill a Mockingbird:themes,social,issues,or a character.I am having major problems

    asked by need help please!! on March 18, 2007
  89. algebra

    1. - 5(2x+2)is greater than or equal to -10x - 17 (1 point) a)x is greater than or equal to 7 b)x is less than or equal to 19 c)all real numbers d)no solution

    asked by Emily on October 27, 2011
  90. algebra

    determine the nature of the solutions of the equation. Two real solutions, two imaginary solutions, or one real solution. 2t^2-4t=0

    asked by sam on July 11, 2010
  91. math

    Which ordered pair is not a solution of y = -12x - 3? a. (-3,33)* b. (8,-98) c.(-9, 105) d.(3,-39) plz check plz plz plz plz plz

    asked by alabama joe on March 15, 2019
  92. algebra

    Solve the system of linear equations by graphing 3x+y=0 2x-y=5 Graph the system What is the solution of the system of equations?

    asked by Shannon on March 10, 2015
  93. algebra inequalities

    can you check these tell if the number after the: color is a solution x < 7; 7 i say yes p > -3;3 i say yes k is greater than or equal to 5; 0 i say no 3z is less than or equal to 12;4 i say yes n - 5 > 3; 6 i say no 2g + 8 is geater than or equal to 3;-1

    asked by marko on November 1, 2011
  94. Chemistry

    In a saturated solution of silver phosphate, the concentration of silver is 4.5 x 10^-4 mol/L. What is the Ksp of silver phosphate?

    asked by Brittany on June 17, 2009
  95. chemistry

    What is the pH of the solution created by combining 12.00 mL of the 0.10 M base with 8.00 mL of the 0.10 M acid acid: acetic acid base: ammonia

    asked by unknown on April 9, 2008
  96. Quadratic Equations and Functions

    I started having trouble on part (c), and I need to know this before I can go onto the other problems. Plz help! The parabola shown at the right (no picture, sorry) is of the form y=x^2+bx+c. The graph's y-intercept is (0,2), the axis of symmetry is -2.5

    asked by Emily on February 4, 2007
  97. Chemistry

    I've been working on this problem for hours and cant figure it out. I know it should be simple, but I'm stuck... The question is... Describe how to prepare 1.00L of a 1.0% (w/v) NaOH from a 2.0 M NaOH. *I need to figure out how many ml of the stock

    asked by James on January 10, 2013
  98. Chemistry

    What mass of silver chloride can be prepared by the reaction of 160.0 mL of 0.25 M silver nitrate with 110.0 mL of 0.20 M calcium chloride? Calculate the concentrations of each ion remaining in solution after precipitation is complete. (Enter a 0 if none

    asked by Sam on March 13, 2013
  99. Electroplating in Chem

    Today I began an electroplating lab between a copper strip and a coin in electrolyte solution with a battery. I am struggling to figure out the copper half-reactions that occured, and whether they are reduction or oxidation. I only need two, and one is

    asked by kat on May 9, 2016
  100. Chemistry

    A 10.0 mL sample of supernatant liquid from the system described by equation 1 was titrated with 0.01022 M EDTA solution to an end-point at 16.90 mL. Titration of the blank gave a titre (end-point) at 1.45 mL. Determine the titration volume required to

    asked by Mara on November 17, 2015