Popular questions and responses by Richard
  1. More Organic Chem.

    1. Would you expect ibuprofen to be soluble or insoluble in 1.0 M NaOH? Explain. 2. Thymol is very slightly soluble in water and very soluble in 1.0 M NaOH. Explain. Any info. would help! Below are two web pages. The first shows ibuprofen has a -COOH group

    asked on February 5, 2007
  2. chem class

    A 25.00-mL sample of 0.723 M HClO4 is titrated with a 0.273 M KOH solution. The H3O+ concentration after the addition of 10.0 mL of KOH is ???? M.

    asked on November 23, 2010
  3. chemistry

    Calculate the number of moles of FeSO4 in 25cm3 of a 0.2mol dm3 solution

    asked on June 21, 2011
  4. Chem.

    If 0.130 g of p-aminophenol is allowed to react with excess acetic anhydride , what is the theoretical yield of acetaminophen in moles? In grams? p-amino. - MW: 109.13g aceta. - MW: 151.16 g ** I just forgot how to do this, I know it's probably REALLY

    asked on February 27, 2007
  5. Physics

    What is the value of each of the angles of a triangle whose sides are 95, 150, 190 cm in length? I have tried to do this problem, don't get me wrong, but I don't really know where to go. Can someone tell me how to even approach this problem? The textbook

    asked on July 6, 2014
  6. Chemistry

    Can anyone help me check my classifications of these into metallic, ionic, molecular or covalent network, and if I am wrong tell me why Aluminum - Mettalic Ascorbic acid - ionic Graphite - covalent Paraffin - molecular Palmitic acid - ionic Sodium chloride

    asked on February 20, 2018
  7. College Algebra

    The sum of three consecutive natural numbers is 966. Find the numbers.

    asked on July 23, 2015
  8. Physics

    a uniform metre rule pivoted at R, the 70cm mark. Two forces 0.1 N and 0.4 N are applied at Q, the 60cm mark and S, the 85cm mark. If the metre rule us kept in equilibrium, by the forces, calculate the weight of the metre rule.

    asked on November 4, 2018
  9. Physics

    A uniform metre rule AB us balanced on a knife edge which is 55cm from B. If a mass of 10g is hung at P, which is 10cm from A, calculate the mass of the metre rule. Please HELLLLP URGENTLY!!!!!!😥😥😥😥😥😥😫😫😫😫😫

    asked on October 23, 2018
  10. Chemistry check my answer?

    Hi! is my answer correct? Consider the following chemical reaction: H2 (g) + I2 (g) 2HI (g) At equilibrium in a particular experiment, the concentrations of H2, I2, and HI were 0.15 M, 0.033 M, and 0.55 M, respectively. The value ofKeq for this reaction is

    asked on October 25, 2010
  11. Math

    Write 116 2/3 as a fraction or mixed number.

    asked on August 16, 2009
  12. chemistry.

    Lithium hydroxide reacts with carbon dioxide as follow. 2LiOH + CO2________ Li2CO3 + H2O What mass (in grams) of Lithium hydroxide is need to react with 11 g of carbon dioxide?

    asked on September 28, 2009
  13. Science

    Which of the following would be the best explanation for the existence of the Andes Mountains along the west coast of South America? (1) the collision of two tectonic plates (2) the gravitational pull of the sun, the moon, and the planets 3) the magnetic

    asked on September 26, 2020
  14. college physical science

    According to table 1.3, what volume of iron would be needed to balance a 1.00cm3 sample of lead on a two pan laboratory balance? Table 1.3 shows densities g/cm3 such as iron=7.87g/cm3 and lead is 11.4g/cm3

    asked on August 29, 2010
  15. Physics

    A 0.150 kg particle moves along an x axis according to x(t) = -13.00 + 2.00t + 3.50t2 - 2.50t3, with x in meters and t in seconds. In unit-vector notation, what is the net force acting on the particle at t = 3.45 s? I tried solving using s=Vit + (.5)at^2

    asked on September 22, 2009
  16. science

    if a substance is known to enter a cell by diffusion, what effect would raising the temperature have on the cell? Why does it have this effect?

    asked on November 4, 2007
  17. physics

    a ball projected vertically upwards from the top of the tower 60 meters high with a velocity of 30 meters per second. what is the maximum height above the ground? how long does it take to reach the ground?

    asked on August 28, 2016
  18. chemistry

    1.Use the Vsepr theory to predict and explain the shape and bond angle of each of the molecules SCI2 and C2CL2. 2.Deduce whether or not each molecule is polar, giving a reason for your answer...Any help please??

    asked on February 28, 2010
  19. business

    Direct verse indirect cost Estep Construction Company is composed of two divisions: (1) Home Construction and (2) Commercial Construction .The Home Construction Division is in the process of building 12 houses and the Commercial Division is working on 3

    asked on March 26, 2011
  20. 9th grade

    A square made by a length of string 8 cm long is reshaped into a circle. What is the circumference of the circle

    asked on September 24, 2010
  21. Biology

    The density of ice is 916.7 kilograms per cubic meter at 0 degrees Celsius under atmospheric pressure. Columbia Glacier, in Alaska, loses about 4 billion metric tons of ice each year. About what volume of water melts from the glacier each year? Im confused

    asked on September 28, 2019
  22. Physics

    a mercury in glass thermometer reads -20°C at the ice point and 100°C at the steam point. Calculate celcius temperature corresponding to 70°C on the thermometer

    asked on June 6, 2019
  23. chemistry correction

    1. Which two elements react vigorously with each other? A: Chlorine and lithium B:Chlorine and potassium C:iodine and lithium D:iodine and potassium my answer is B 2. which statement about electronegativty is correct. A: Electronegativity decrease across a

    asked on March 11, 2010
  24. Math

    First Estimate the answer. Then find the exact answer. Simplify your answer if possible. 9*2/7*8/5/7

    asked on September 13, 2009
  25. hardware

    what is hardware

    asked on June 8, 2008
  26. Organic Chem.

    When a tlc plate was developed the solvent front ran off the top of the plate, why? A two component mixture containing a dicarboxylic acid and tricarboxylic acid gave only one spot with an Rf value of 0.05. Solvent used; hexane. What went wrong? Solvent

    asked on February 5, 2007
  27. science(physics)

    A piece of copper block of mass 24g at 230 degree celsius is placed in a copper calorimeter of mass 60g containing 54g of water at 31 degree celsius.Assuming heat losses are negligible,calculate the final steady temperature of the mixture (Specific heat

    asked on July 7, 2019
  28. Math

    A child's desk is made so that the dimensions are two-thirds the dimensions of a full-size adult desk. Suppose the top of the full-size desk measures 54 inches long by 36 inches wide. What is the perimeter and area of the topof the child's desk?

    asked on September 24, 2015
  29. geometry

    What happened when two fruit companies merged?

    asked on November 16, 2011
  30. Lab conclusion- HELP!

    I' am currently trying to wrie a couple of lab conclusions and having a hard time coming up with good points to make for the following lab experiment: Thin layer chorotography If anyone has a few minutes to give me a couple tips on how to improve this. I

    asked on February 5, 2007
  31. Mathematics

    Select 5 numbers from 1to 90numbers,and we have win and machine side.if a numbers is plays .win 78-9-64-86-13&mach61-2-21-72-70and the following week plays win 54-66-13-42-15&mach12-32-22-8-61. What will be next win & machine numbers for the next week.

    asked on September 29, 2020
  32. Maths

    a map with a scale of 1cm to 5km has an area of 405cmsquare. what is the actual area of this map on the ground?

    asked on April 28, 2016

    How to prepare a 500ml 0.2M NaOH solution from 2.0M NaOH solution

    asked on July 10, 2013
  34. English

    Reading the book Twilight by Stephenie Meyer. Will have to write book report in class 11/13/07. Has anyone read the book and written a book report on it.

    asked on November 8, 2007
  35. math

    A number is written with the following factorization:2² x 3 x 5⁴ x 8 x 11².Is this factorization a prime factorization? Explain why or why not. If it is not correct, give the correct prime factorization of the number.

    asked on December 6, 2018
  36. algebra

    A 12 - ft ladder leans against the side of a house. The bottom of the ladder is 6 ft from the side of the house. How high is the top of the ladder from the ground? If necessary, round your answer to the nearest tenth.

    asked on August 10, 2017
  37. Physics (Thin Film Interference)

    A layer of transparent plastic (n=1.61) on glass (n=1.52) looks dark when viewed in reflected light whose wavelength is 589 nanometers in vacuum. Find the two smallest possible nonzero values for the thickness of the layer. Answers are 183 nm and 366 but I

    asked on October 11, 2015
  38. precalculus

    use pascal's triangle to expand the expression (2x-3y)^3

    asked on May 9, 2015
  39. Physics

    A bead slides without friction around a loop- the-loop. The bead is released from a height of 12.9 m from the bottom of the loop-the- loop which has a radius 4 m. The acceleration of gravity is 9.8 m/s2 . A 4m 12.9 m What is its speed at point A ? Answer

    asked on December 14, 2012
  40. math

    solve by the elimination method: 9x-9y=18 7y-3x=-8 please solve step by step thank you for your help

    asked on July 25, 2011
  41. chem

    What is the [OH-] for a solution at 25°C that has [H3O+] = 8.23 × 10-2 M?

    asked on March 5, 2011
  42. trig

    Graph three periods of the function. (identify period and phase shift and intercepts) y = f(x) = √3/2 sin(2x) - 1/2 cos(2x) if you can't graph it can you at least get it into that simpler form which is graph able.

    asked on May 5, 2010
  43. chemistry

    Magnesium reacts with HCl(aq) to form MgCl2 and H2(g) ____ Mg(s) + ____ HCl(aq) -----> ____ MgCl2(aq) + ____ H2(g) The following data was collected for the above reaction: Mg (g) 5% (m/v) HCl (ml) H2 gas produced (ml) 0.50 10 167 0.50 20 333 0.50 30 500

    asked on January 29, 2010
  44. math

    Is The factors of 385 = 1,5,7,55,77,385?

    asked on September 5, 2009
  45. org. chem

    why is it easier to remove excess acetic acid from the products than excess isopentyl alcohol? from the products of what? Did you perform an experiment in class and this is one of the lab questions? If so you will need to explain what you did in some

    asked on March 7, 2007
  46. Physics

    (PLEASE HELP ME URGENTLY) The electrical resistances of the element in a platinum resistance thermometer at 100°C, 0°C and room temperature are 75.000W, 63.000W and 64.992W respectively. Use these data to determine the room temperature. (PLEASE HELP ME

    asked on June 7, 2019
  47. Marketing

    Explanation of leadership without followership is nonesense and impossible in relation to the principles of marketing management..... PLLLLEAAASE ASSIST ME!!!!

    asked on October 24, 2018
  48. Physics

    A uniform metre rule of mass 90g is pivoted at the 40cm mark. If the rule is in equilibrum with an unknown mass, M placed at the 10cm mark and 72g mass at the 70cm mark, determine M. Please help me urgently!!

    asked on October 23, 2018
  49. Chemistry

    Ammonia (NH3) reacts with oxygen to produce nitric oxide (NO) and water (see balanced equation below). How many grams of oxygen do you need to react with 21.4 g ammonia? __4_NH3 + __5_O2 → __4_NO + _6__H2O

    asked on October 2, 2016
  50. Algebra

    Explain how you can tell the function is not linear by using points on its graph. Make sure to include in your answer the Points you used to determine that the function is not linear.

    asked on April 28, 2016
  51. Chemistry

    Part 1 of 2 Write the balanced molecular equation for the reaction between iron metal (the nail) and aqueous copper II sulfate and classify this reaction. Include the states: solid (s), liquid (l), aqueous (aq), or gas (g). Use your observations to help

    asked on January 11, 2015
  52. Science

    Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.

    asked on January 9, 2014
  53. Macroeconomics

    Graph the following aggregate supply and demand curves (be sure to draw to scale). Real GDP (in $ trillions) Price Level Supplied Demanded Increase / Decrease 100 4 16 110 10 15 140 14 12 200 15 6

    asked on April 15, 2013
  54. chemestry

    How many grams of O2 are needed to produce 45.8 grams of Fe2O3 in the following reaction? 4Fe(s)+3O2(g) - 2Fe2O3(s)

    asked on February 27, 2013
  55. Physics

    Differenciate between speed and velocity

    asked on January 22, 2013
  56. Government

    If you asked the same question about an upcoming election to many people,you would be conducting a? A.Scientific poll B.Straw Vote C.Public Agenda D.Representative Sample

    asked on May 10, 2012
  57. Maths

    14 metres of rope costs €9.52. If Joe bought 21 metres, how much change out of €20.00 do Joe get? Is there a shorter way of doing this other than dividing, multiplying and then subtracting?

    asked on March 22, 2012
  58. Math-Statistics

    Find a confidence interval for ƒÊ assuming that each sample is from a normal population. a. P x = 14, ƒÐ = 4, n = 5, 90 percent confidence b. P x = 37, ƒÐ = 5, n = 15, 99 percent confidence c. P x = 121, ƒÐ = 15, n = 25, 95 percent confidence

    asked on December 6, 2011
  59. Physics

    What minimum strength of magnetic field is required to balance the gravitational force on a proton moving at speed 6*10^6 m/s?

    asked on December 4, 2011
  60. Physics

    What is the fundamental frequency for a 62 cm banjo string if the speed of waves on the string is 470 m/s?

    asked on November 7, 2011
  61. Physics

    How long is a wavelength of infrasound with a frequency of 4 Hz?

    asked on November 7, 2011
  62. Physics

    Radio waves travel at the speed of light, which is 3.00 108 m/s. What is the wavelength for a FM station broadcasting at 105.9 MHz (the prefix M is "mega" and means 106)?

    asked on November 7, 2011
  63. math

    a 4 digit number my 2 nd digitis twice my 3 digit the sum of all my digits is 3 times greater than my last digit the productof my 3rd and 4th digits is 12 times greater than the ratio of my 2nd to 3rd whats my number?

    asked on August 18, 2011
  64. college chem

    The cation M2+ reacts with NH3 to form a series of complex ions as follows: M2+ + NH3 M(NH3)2+ K1 = 102 M(NH3)2+ + NH3 M(NH3)2 2+ K2 = 103 M(NH3)2 2+ + NH3 M(NH3)3 2+ K3 = 102 A 1.0 × 10–3 mol sample of M(NO3)2 is added to 1.0 L of 15.0 M NH3 (Kb = 1.8

    asked on April 24, 2011
  65. chem101

    propyl Bromide reacts with Mg, Propanone, H+ to yeild what?

    asked on March 26, 2011
  66. chem101

    Hydrogen gas can be produced in the lab by the reaction of magnesium metal and hydrochloric acid. Mg + 2 HC -> MgCl2 + H2 How many grams of hydrogen gas will be produce if 5.00 g of magnesium metal is dissolved in excess acid.

    asked on March 24, 2011
  67. 3rd grade

    What is a number sentence that shows the same product as the product of 9 and 2

    asked on December 9, 2010
  68. english

    How might readers react if the topic sentences in an essay did not coincide with the supporting points, and why would their reaction be justified?

    asked on March 28, 2011
  69. Chemistry

    A buffer prepared by mixing equal amounts of the salts Na2HPo4 and NaH2PO4 to give a total phosphate concentration of 0.1M. What is the concentration of Na ions? I believe it is 0.3M but am having trouble understanding why when I write out the dissociation

    asked on June 30, 2010
  70. Physics

    Having trouble determ the formulas for the follow problems. 2. If an automobile travels at 30 km/hr. for 2 hours, how far does it go? 60 km 3. At time = 0 an automobile already traveling at 30 km/hr. accelerates at 3m/s2 for 2 seconds. During these two

    asked on May 29, 2010
  71. Physics hard...

    Young's Modulus (Y) 20 X 1010 N/m2 Shear Modulus (S) 8.1 X 1010 N/m2 Bulk Modulus (B) 16 X 1010 N/m2 The table to the above represents various properties of steel. You have steel wire 4.9 meters in length that stretches 0.16 cm when subjected to a force of

    asked on May 6, 2010
  72. Trigonometry

    Find all solutions for the following equation in the interval 0 ≤ x

    asked on May 4, 2010
  73. social studies

    Why did Mao Zeodong led the cummunists to power in china

    asked on April 22, 2010
  74. Math

    The exhibit hall at the fair is dividid into three sections. Tow-fifths of the exhibits are in section B of the hall, and another two-fifths ain in section C. What fraction of the exhibits are in located in section A? We have multiple choice answers. Thank

    asked on March 1, 2010
  75. chemistry

    1.predict and expalain the order of melting point for propanol, butane, and proanone with refernce to their intermolecular forces. 2. The element sodium, aluminum, silicon, phosphrous, and sulfur are in periods 3 of the periodic table. Decribes the

    asked on February 26, 2010
  76. history

    What were the main elements of Johnson’s War on Poverty?

    asked on December 14, 2009
  77. Calculus

    Would someone please tell me how to solve these two problems? Find the indefinite integral: x(x-1)^5 dx (v^2)(1-v)^6 dv

    asked on November 18, 2009
  78. 6th grade math

    28 x 15 simplify by using distributive property,

    asked on September 10, 2008
  79. math

    write 3x^2 +8x-25 in the form a(x+h)^2,where a,h and k are real numbers

    asked on April 9, 2008
  80. mathFormula

    Formula for calculating cubic feet. length(in feet) x width(in feet) x height(in feet) = volume in cubic feet. Thank you DrBob That's for a cube or four sided regular figures. For a cylinder, it's pi*(radius2)*height and there are other formulas for other

    asked on August 20, 2007
  81. Mathematics

    An arc of length 28cm subtend an angle of 24° at the center of the circle. In the same circle what does an arc of 35cm subtend

    asked on July 23, 2020
  82. chemistry

    explain why helium is used instead of hydrogen in balloons for meteorological research

    asked on November 21, 2019
  83. Science

    A toy rocket of 5.0 kg is launched from rest and reaches a height of 100 M in two seconds. What is the work done by the engine during this non acceleration stage?

    asked on April 28, 2019
  84. Statistics

    A politician is preparing to speak to voters in Connecticut. He DOES NOT favor gun control laws. However, a survey of 1200 voters from this state resulted in 984 voters that supported some level of gun control laws. (Assume a good random sample was taken).

    asked on April 22, 2019
  85. math

    if you made a stack of nickels 100 inches tall,how many nickels would you need

    asked on January 18, 2019
  86. Physics

    If light travels through a medium at a speed of 1.987 x 10^8 m/s, what is the index of refraction of the medium? * 1.33 1.36 1.51 1.53

    asked on April 8, 2018
  87. Math - Algebra

    An architect is designing a building in the shape of a rectangular pyramid. The number of windows on each floor forms an arithmetic sequence. There are 76 windows on the 7th floor, 68 on the 8th floor, and 4 on the very last floor Find an explicit formula

    asked on February 19, 2018
  88. 5th grade math equation

    I have tried everything to help my son and I can't figure it out. I am trying to get an end result of 38 out of the following equation. We have to add parentheses to make it equal 38 any help !!! 3+6*5+4/2-7

    asked on March 26, 2017
  89. Chemistry

    Thanks to Dr. Bob for answering all these questions! I always do poorly on conceptual problems. Consider the following equilibrium system at 25°C and select the true statement below: H2PO4−(aq) + SO42−(aq) ↔ HSO4−(aq) + HPO42−(aq) ΔG°rxn > 0

    asked on February 27, 2017
  90. calculus

    How would you use series to evaluate the lim(x->0) of (x-arctanx)/x^3? I'm getting stuck, and the answer says it's 1/3 but I don't know how they got there.

    asked on February 26, 2017
  91. calculus

    How would you determine the power series of 1/(1-x)^3. I know that the series of 1/(1-x) is x^n, but how would you manipulate it for this scenario?

    asked on February 26, 2017
  92. math

    there are 20 students in mark`s homeroom class. Ten percent of the students in marks homeroom class are also in art class He finds the number of students in his homeroom class who are also in art class like this . Can you tell me the answer of how many

    asked on February 16, 2017
  93. math-integrating factor

    dy/dx - y/x = 0 I got 1/x, but I am not sure if this is right or not.

    asked on December 25, 2016
  94. Algebra 2

    There are 41 individuals in a grocery store, of which 18 are female. the total number of individuals who are 30 years old or older is 24 of which 10 are female. If an individual is randomly selected, what is the probability that they are either male or 30

    asked on November 17, 2016
  95. chemistry

    pH of 1.0 x 10-8 M RbOH

    asked on July 24, 2016
  96. math

    A flame is ejected vertically upward from the groung at 15m/s.Find the height of the flame after 2.5seconds

    asked on June 29, 2016
  97. life orientation

    Clealy describe a recent corruption and fraud cases in the country making headlines in the media

    asked on April 29, 2016
  98. Physics

    A Ball Of Mass 0.25kg Losses Half Of Its Velocity When It Makes A Head On Collision With An Identical Ball Q At Rest.After The Collision,Q Moves off with a speed of 2m/s in the original direction of p.calculate the initial velocity of p.

    asked on April 17, 2016
  99. Intro to Chemistry

    A 9.40-L container holds a mixture of two gases at 47 °C. The partial pressures of gas A and gas B, respectively, are 0.344 atm and 0.520 atm. If 0.160 mol of a third gas is added with no change in volume or temperature, what will the total pressure

    asked on March 9, 2016

    1. ZG Jewelers purchased fashion bracelets for $38.87. This jewelry store regularly marks up fashion merchandise 52% of the selling price. What is the minimum selling price that ZG Jewelers should charge? 57.20 59.23 80.98 94.94

    asked on February 25, 2016


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