Questions Asked in 2007

Most Popular Questions of 2007

  1. chemistry

    Is NH4+ a polar or nonpolar bond?

    asked by Lin on November 30, 2007
  2. Physics;Help!!!!!!

    There is apparently no one online who can help with physics questions right now. Please check back later to see if a physics teacher has addressed your question. Multiple posts won't get faster answers. Thanks. =) The question is in the first question

    asked by Writeacher on June 7, 2007
  3. CHEM

    Help on part "c": The forensic technician at a crime scene has just prepared a luminol stock solution by adding 19.0g of luminol into a total volume of 75.0mL of H2O. a)What is the molarity of the stock solution of luminol? anwer I got: molarity of luminol

    asked by K on October 18, 2007
  4. Senior Paper

    hey gurl IP address is your Internet Protocol address. Its kinda of like your street address but for your computer like how you put a return address on letters your IP address is recorded when visiting websites and posting things so the website operators

    asked by Haley on July 6, 2007
  5. Chemistry

    A colourless solution contains one type of ion. When one adds dilute HCl to it, a white precipitate initially forms. However, once more of the HCl solution is added, the precipitate dissolves. Explain why the ion is Pb2+ and not Al3+, Hg22+, Cu2+ nor Ag+.

    asked by Vic on September 3, 2007
  6. EFFECTIVE WRITING

    WHAT ARE SOME ADVANTAGES FOR BOTH REVIWER AND WRITER-OF PEER REVIEWS? HOW WOULD YOU ENCOURAGE A RELUCTANT http://www.jiskha.com/search/search.cgi?query=HOW+WOULD+YOU+ENCOURAGE+A+RELUCTANT Idella, when you type in all-caps, two things happen: ~~it's harder

    asked by IDELLA JONES on April 13, 2007
  7. Physics

    A wheel with rotational inertia I is mounted on a fixed, fricitonless axle. The angular speed w of the wheel is inccreased from zero to w_f in a time interval T. 1: What is the average net torque on the wheel during the time interval, T? a) w_f/T b)w_f/T^2

    asked by Tammy on March 25, 2007
  8. physics.

    A 20.0 kg cannon ball is fired from a cannnon with muzzle speed of 1000 m/s at an angle of 37.0 with the horizontal. A second ball is fired at an angle of 90.0. Use the conservation of energy principle to find a] the maximum height reached by each ball and

    asked by Jean on March 15, 2007
  9. Physics

    A cylinder is fitted with a piston, beneath which is a spring, as in the drawing. The cylinder is open at the top. Friction is absent. The spring constant of the spring is 4100 N/m. The piston has a negligible mass and a radius of 0.023 m. (a) When air

    asked by Mary on April 24, 2007
  10. Math

    Why Does The President Put Vegetables in His Blender? P.S.: It's puzzle 163 HELP!!!!!!!!!

    asked by Dorina on December 9, 2007
  11. Chemistry II

    C4H4 (g) + 2 H2 (g) --> C4H8 (g) Combustion reactions involve reacting a substance with oxygen. When compounds containing carbon and hydrogen are combusted, carbon dioxide and water are the products. Using the enthalpies of combustion for C4H4 (-2341

    asked by Jayd on May 20, 2007
  12. MATH URGENT!

    Ok I don't understand how to find similar figures when using proportions. Can someone explain it to me? Two figures that have the same shape are said to be similar. When two figures are similar, the ratios of the lengths of their corresponding sides are

    asked by Ashley on April 24, 2007
  13. Chemistry

    In a thermochemistry experiment the reaction of 0.0857 g of an unknown metal and an excess of 4.0 M HCl resulted in a 0.210 mL decrease in the volume of an ice/water mixture. Calculate the enthalpy of this reaction per 1 g of metal reacted. Needed data:

    asked by Raj on December 1, 2007
  14. reading

    is the word penguin a metaphor?? please answer bye. It could be, depending on how it is used. Metaphors are totally dependent on usage and how they are compared. The men were penguins for the dinner, waddling to and fro. ya but could i use it as a metaphor

    asked by brittany on January 4, 2007
  15. spelling

    what is the answer to this analogy brother:mother::fly:???? must start with the letters scr,spr,str,or thr brother:mother:fly brother:mother::fly:???? must end with scr, spr, str, thr brother:mother::fly:???? must end with scr, spr, str, thr i don't know i

    asked by austin on January 16, 2007
  16. CHEM

    Which statement best describes the polarity of SF_4Cl_2?? (or: SF4Cl2, if that helps more) 1. Always polar. 2. Always nonpolar. 3. Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar. & how can you tell for certain??? I

    asked by K on November 26, 2007
  17. CHEMISTRY

    HOW CAN U TELL IF HNO3 +KNO3 IS A BUFFER SOLUTION A buffer solution must contain a weak acid and its conjugate base OR a weak base and its conjugate acid. HNO3 is a strong base and KNO3 is the salt of a strong base (KOH) and a strong acid (HNO3);

    asked by CANDY on February 27, 2007
  18. CHEM

    You are a researcher for a golf club manufacturer. You are given two identical looking cubes of a metal alloy. You are informed that they are made of the exact same material, but one is a crystalline, while the other is amorphous. It is your job to

    asked by K on November 28, 2007
  19. CHEM

    What are the expected bond angles in ICl4+ (or) ICl_4^+ ?? I think that I have the stucture drawn correcty: I is the central atom with one lone pair above it. I then have the Cl's with 6dots around them & then bonded, singly, to the "I". Two "Cl's" go

    asked by K on November 26, 2007
  20. Sales tax

    tom paid 695.5 for a tv when 7% sales tax was included in that price what was the price of the tv before the tax and how much sales tax did tom pay? You can set it up this way: 1.07x = 695.5 x = _______ That will tell you the price of the TV. The

    asked by Arkuk on April 13, 2007
  21. Physics

    This is probably a really easy question, but I just don't know how to set it up. An object in equilibrium has three forces exerted on it. A 33 N force acts at 90 degrees from the x-axis and a 44 N force acts at 60 degrees. What are the magnitude and

    asked by Corin on November 12, 2007
  22. Physics

    One end of a uniform meter stick is placed against a vertical wall. The other end is held by a lightweight cord that makes an angle, theta, with the stick. The coefficient of static friction between the end of the meter stick and the wall is 0.390. A. what

    asked by Karla on April 3, 2007
  23. physics!! plz answer me!

    A 0.15 kg baseball moving at +26 m/s is slowed to a stop by a catcher who exerts a constant force of -390 N. How long does it take this force to stop the ball? How far does the ball travel before stopping? plz plz plz help!!

    asked by julia on December 10, 2007
  24. physics

    If a gasoline engine has an efficiency of 21 percent and loses 780 J to the cooling system and exhaust during each cycle, how much work is done by the engine? Is it 3709.5??? Chemical energy in (as fuel and oxygen) = Work out + Heat out 21% is the ratio of

    asked by anonymous on February 15, 2007
  25. african literature

    what is the symbolic item will represent the poem "africa" by david diop???

    asked by klar maesen on December 4, 2007
  26. Physics

    A small first aid kit is dropped by a rock climber who is descending steadily at 1.3 m/s. After 2.5 s, what is the velocity of the first-aid kit, and how far is the kit below the climber? This problem seems like it should be easy, but I'm not sure which

    asked by Stephanie on September 30, 2007
  27. CHEM

    A cylinder with a movable piston contains 2.00g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the

    asked by K on October 28, 2007
  28. chem

    3.0 mol sample of KClO3 was decomposed according to the equation 2KClO3 = 2KCl + 3 O2 How many moles of O2 are formed assuming 100% yield? is it 3 moles? I don't want to work through the details of this problem completely. Tell me what you don't understand

    asked by jill on July 17, 2007
  29. physics

    A .100 kg meter stick is supported at its 40.0 cm mark by a string attached to the ceiling. A .700 kg mass hangs vertically from the 5.00 cm mark. A mass, m, is attached somewhere on the meter stick to keep it horizontal and in rotational and translational

    asked by Anonymous on December 4, 2007
  30. **CHEM**

    Arrange the following elements in order of decreasing atomic radius: Cs, Sb, S, Pb, Se *(list from largest to smallest...or..."the correct ranking cannot be determined") ***I think the answer 'should be', from largest to smallest: ***Cs, Pb, Sb, Se,

    asked by K on November 13, 2007
  31. chemistry

    how do i write a net ionic equation for Lead (II) Nitrate and Sodium Carbonate react to form Lead Carbonate and Sodium Nitrate??

    asked by caren on December 11, 2007
  32. Chemistry

    Which radioactive sample would contain the greatest remaining mass of the radioactive isotope after 10 years? A. 2.0 grams of 198 Au B. 2.0 grams of 42 K C. 4.0 grams of 32 P D. 4.0 grams of 60 Co By the way the numbers next to the elements are their

    asked by Sanjay on March 3, 2007
  33. CHEM

    The mass of a golf ball is 45.9g. If it leaves the tee with a speed of 72.0 m/s, what is its corresponding wavelength? Express your answer numerically in meters. Would the correct answer be: lambda=h/mv lambda=6.626*10^-34/(45.9g)(72.0m/s)

    asked by K on November 5, 2007
  34. English

    In high school we have to read great expectations by Charles Dickens for honors English but i do not understand the essay I have to write. Could someone help me please? Compare and contrast the ways in which the protagonist is stuck between two worlds,

    asked by Natalie on September 1, 2007
  35. AP chem

    A 0.345g sample of anhydrous BeC2O4, which contains an inert impurity, was dissolved in a sufficient water to produce 100ml of solution. A 20.0ml portion of the solution was titrated w/ KMnO4(aq). The balanced equation for the reaction that occurred is as

    asked by michelle on January 4, 2007
  36. science

    in a baseball-hitting contest at the office picnic, five men participated named: Biff, Carl, Fred, Marty, and Tom. Their last names in alphabetical order are Jenkins, Keech, McNabb, Miller, and Winslow. The distance that each man hit the ball in feet are:

    asked by angie on September 26, 2007
  37. Physics

    A spring has a force constant of 100N/m and an unstretched lenght of .07 m. One end is attached to a post that is free to rotate in the center of a smooth table. The other end is attatched to a 1 kg disc moving in uniform circular motion on the table,

    asked by Tammy on March 25, 2007
  38. Economics

    Questions: Are the following workers more likely to experience short-term or long-term unemployment? Explain. a. A construction worker laid off because of bad weather. b. A manufacturing worker who loses her job at a plant in an isolated area. c. A

    asked by Sarah on March 24, 2007
  39. maths

    what fraction of 30p is 5p?

    asked by nishchay on November 26, 2007
  40. Math Word Problem

    Counting Chicken Wings At Annie's Home-Cooked Chicken Wings Restaurant, chicken wings are served by the bucket. The Biggest Bucket O'Wings is really big! Figure out how many wings are in the bucket. If the wings are removed two at a time, one wing will be

    asked by Linda on December 11, 2007
  41. Chemisry

    what mass of protons would be required to just neutralize the charge of 1.0g of electrons? how do I answer this? You know the mass of an electron. Calculate how many are in 1 gram. You will need the same number of protons. Knowing the mass of a proton

    asked by Chris on February 8, 2007
  42. Essay on UNITED WE STAND, DIVIDED WE FALL

    Can someone help me with the essay writing please First you should make a list of reasons you agree or disagree with this topic. Arrange these items in a logical order. Next, write an introductory paragraph, briefly stating these reasons, and concluding

    asked by Karan Raichura on July 8, 2007
  43. Chemistry

    At 1100 K, Kp=0.25 for the following reaction. 2SO2(g) + O2(g) (reversible arrows) 2SO3(g) What is the value of K at this temperature? This is what I have so far: I did Kc=0.25(1100(0.0821))^-1 and got Kc=0.00276. That is incorrect. Why? What did I do

    asked by Taasha on July 31, 2007
  44. Business Communications

    Your boss wants to send a brief email message welcoming employees recently transferred to your department from your Hong Kong branch. They all speak English, but your boss asks you to review his message for clarity. What would you suggest your boss change

    asked by Alicia on November 14, 2007
  45. AP Chem

    A solution of potassium phosphate is mixed with a solution of calcium acetate. I am supposed to write a net ionic equation. Doesn't need to be balanced. Here is what I did: K3PO4(aq) + Ca(C2H3O2)2 --> KC2H3O2 + Ca3PO4 3K+ + PO4-3 + Ca+2 2(C2H3O2-) --> K+ +

    asked by Please check on October 3, 2007
  46. s.s

    before there was mills what was used to make thread? Before there were mills and factories, people made thread at home on spinning wheels. Check this site for more information and a picture of a spinning wheel. http://en.wikipedia.org/wiki/Spinning_wheel

    asked by Melsissa on February 8, 2007
  47. COLLEGE PHYSICS

    a uniform bridge span weighs 50x10^3 and is 40m long. A car weighing 15X10^3 is parked with its center of gravity located 12m from the right pier. what upward support force does the left pier provide? im lost....this is what i think im supposed to do

    asked by natali on November 11, 2007
  48. Geometry

    Given: ABCD is a parallelogram;

    asked by DANIELLE on June 13, 2007
  49. Chemistry

    Which of these compounds contain elements that do not follow the octet rule? Explain. (Note: All the numbers are superscripts) A. NF3 B. OF2 C. H2S D. NI3 My understanding of the octet rule..is that it is not satisified in molecules w/ an odd no. of

    asked by Anonymous on November 28, 2007
  50. Chemistry

    What volume of O2 is required to react with excess CS2 to produce 4.0L of CO2 Assume all gases at STP. Not sure what I am doing wrong, but the answer I am getting is not one of the answers. 4L/X mole=22.4 L/1 mole ===>.1786 mols Balanced equation: O2 + CS2

    asked by T on December 13, 2007
  51. Calculus

    I really need help with this problem an automobile accelerates from rest at 1 + 3(square root)t mph/sec for 9 seconds. How far does it travel in those nine seconds? I have found that the velocity, after nine seconds, is 63 I have figuredout the answer but

    asked by James on April 1, 2007
  52. Chemistry check

    Could someone please just check my answers for this? I want to make sure I did these right. 1. A student reported the mass of ten glass beads as 2.507 +/- 0.015 g. What should the student report as the mass of one bead? Explain your answer. A: The student

    asked by Bryant on January 30, 2007
  53. Chemistry - solubility

    Arrange the following compounds in order of increasing solubility in water: * O2 * LiCl * Br2 * CH3OH Like dissolves like; that is, polar compounds usually are soluble in water and non-polar compounds are not soluble in water. From that description, make

    asked by Belinda on January 2, 2007
  54. developmental reading

    what are the processes in finding the main idea and where can you find the main idea? There are several articles here which discuss the "main idea" of something.

    asked by klar maesen on July 3, 2007
  55. Statistics

    Thank you!! A survey of an urban university (population of 25,450) showed that 750 of 1100 students sampled attended a home football game during the season. What inferences can be made about student attendance at football games? Using the 99% level of

    asked by Jenny on December 19, 2007
  56. Algebra

    I am getting ready to start an Algebra class for the first time and I was wondering what challenges people have with learning and using algebra concepts. Also what are the best ways to over come math anxiety? The best way? Learn the language of algebra.

    asked by jeff on March 20, 2007
  57. physics

    A box of books weighing 300N is shoved the floor of an apartment by a force of 400N exerted downward at an angle of 35.2 degrees below the horizontal. If the coefficient of kinetic friction between box and floor is .570, how long does it take to move the

    asked by Anonymous on October 14, 2007
  58. Chemistry

    Rank the ions in order of decreasing size. Sr2+, Ba2+, Cs Cs>Ba>Sr

    asked by Sally on November 9, 2007
  59. CHEM

    A) a picture shows a container that is sealed at the top by a movable piston. Inside the container is a ideal gas at 1.00atm , 20.0 *C, and 1.00L. (The pic is of a 2L container which has a piston pushed downward to the 1L level. Under the piston, under the

    asked by K on October 28, 2007
  60. help me for this stupid worksheet

    the question is.. why did the ghost decide to haunt city hall? urgh i don't fee like doing it so im hoping someone has the answer :] You might have gotten an answer if you'd told us the source of your question. To which story, poem, play are you referring?

    asked by brooke on January 31, 2007
  61. Calculus

    An equation of the line tangent to the graph of y=(2x+3)/(3x-2) at the point (1,5) is...do I take the derivative of y=(2x+3)/(3x-2) to find the slope and then plug that into y-5=m(x-1)?

    asked by Anonymous on November 18, 2007
  62. chemistry

    Can someone please tell me why I would (or wouldn't) expect a color change if FeCl3 were added to pure aspirin and also to oil of wintergreen? (I know aspirin is mostly salicylic acid, and I'm not even sure what compounds are in oil of wintergreen, I'm

    asked by Lacey on June 12, 2007
  63. CHEM

    The electron from a hydrogen atom drops from an excited state into the ground state. When an electron drops into a lower-energy orbital, energy is released in the form of electromagnetic radiation. Part A: How much energy does the electron have initially

    asked by K on November 4, 2007
  64. Statistics

    A sign on the gas pump of a certain chain of gasoline stations encourages customers to have their oil checked, claiming that one out of every four cars should have its oil topped up. What is the probability that exactly 3 of the next 10 cars entering a

    asked by Matt on February 10, 2007
  65. physics

    A 650 kg weather balloon is designed to lift a 4600 kg package. What volume should the balloon have after being inflated with helium at 0 degrees celcius and 1 atm pressure to lift the total load? The buoyancy force must equal the weight lifted. Let V be

    asked by Anonymous on May 9, 2007
  66. History

    Which of the following was formally amended to the constitution a. equality of rights for women b. prohibition of alcoholic beverages c. prohibition of child labor d. balanced federal budget I know that the 19th amendment is woman suffrage, but the 18th

    asked by Pat on January 20, 2007
  67. SCIENCE

    What type of bonding holds the compound, sodium cyanide, together? The CN bond is covalent. The Na to CN bond is, in most minds, an ionic bond. The electronegativity of C is about 2.1 and that of Na is about 1; therefore, with a difference of about 1 it is

    asked by MARK on February 7, 2007
  68. Chemistry

    Magnesium sulfate is often used it first aid hot-packs giving off heat when dissolved in water. When 2.00 g of MgSO4 dissolves in 15.0 mL of water (d= 1.00g/mL) at 25.0ºC, 1.51 kJ of heat is evolved. A) Write the balanced equation for this reaction. I

    asked by Chris on January 28, 2007
  69. Physics Question......many thanks

    A projectile is shot directly away from Earth's surface. Neglect the rotation of Earth. (a) As a multiple of Earth's radius RE, what is the radial distance a projectile reaches if its initial speed is one-fifth of the escape speed from Earth? ____ times RE

    asked by Jessy on January 15, 2007
  70. chem

    Combustion reactions involve reacting a substance with oxygen. When compounds containing carbon and hydrogen are combusted, carbon dioxide and water are the products. Using the enthalpies of combustion for C4H4 (-2341 kJ/mol), C4H8 (-2755 kJ/mol), and H2

    asked by mel on November 27, 2007
  71. physics

    A 25kg child on a 2m long swing is released from rest when the swing supports make an angle of 30 degrees with the vertical. (a) Neglecting friction, find the child's speed at the lowest position. (b) If the speed of the child at the lowest position is

    asked by Anonymous on October 28, 2007
  72. physics

    The hour hand and the minute hand for the famous Parliament clock tower Big Ben in London are 2.7m and 4.5m long and have masses of 60kg and 100kg, respectively. Calculate the total torque due to weight of these hands about axis of rotation when the time

    asked by Anonymous on December 9, 2007
  73. physics

    1. The efficiency of a squeaky pulley system is 73 percent. The pulleys are used to raise a mass to a certain height. What force is exerted on the machine if a rope is pulled 18.0 m in order to raise a 58 kg mass a height of 3.0 m? Answer: 13.24 N? A

    asked by anonymous on January 17, 2007
  74. math

    You are reducing a map of dimensions 2 ft by 3 ft to fit to a piece of paper 8 in by 10 in. What are the dimensions of largest possible map that can fit on the page? I really don't know how to do this but so far I tried to make 2 proportions by changing

    asked by keisha on November 24, 2007
  75. CountIblis, can i bother you

    Countiblis, i know that you might be busy do you mind if i ask you the following for help.Only if you can please. can you explain to me just one more thing so i can undestand it. Now i have an equation which is : 3x = 3x + 5 which I know has no solution to

    asked by jasmine20 on January 3, 2007
  76. pre-cal... compound interest and modeling data

    Please help me with these 2 problems! 1. Complete the table for the time t necessary for P dollars to triple if interest is compounded continuously at rate r. r= 2%, t=? r= 4%, t=? r= 6%. t=? r= 8%, t=? r= 10%, t=? r= 12%, t=? 2. Draw a scatter plot of the

    asked by anonymous on December 11, 2007
  77. finance

    Residual dividend model Buena Terra Corporation is reviewing its capital budget for the upcoming year. It has paid a $3.00 dividend per share (DPS) for the past several years, and its shareholders expect the dividend to remain constant for the next several

    asked by Linda on September 4, 2007
  78. physics- torque

    1. Find the magnitude of the torque produced by a 3.0 N force applied to a door at a perpendicular distance of 0.25 m from the hinge. 2. A simple pendulum consists of a 3.0 kg point mass hanging at the end of a 2.0 m long light string that is connected to

    asked by Anonymous on January 13, 2007
  79. history- world war 1 entrance

    What slowed down the U.S. entrance into World War 1? I already have many Americans simply did not want to send their sons to war and pacifists urged the United States to set an example for peace. I need one more. Your question presumes it should have been

    asked by Anonymous on February 1, 2007
  80. the odyssey

    what is an important theme in the odyssey,Part 2?Describe the events that illustrate this theme? You need to go to www.sparknotes.com/lit, find Odyssey (in the O section, not the T's), read through the themes section, and decide. Let us know what you

    asked by johnny on March 2, 2007
  81. Chemisrty Lab

    dimensions of a concrete pile are 14 inchesx14 inches x 15 feet. (1 meter=3.28 feet) the pile has 4 faces and 2 ends. 1>what is the surface area in square feet, of a single pile? exclude the ends of the pile. 2>What is the total surface area in square

    asked by NIcole on September 11, 2007
  82. Chemistry (please help me!)

    H2(g) + CO2(g) H20(g) + CO(g) When H2(g) is mixed with CO2(g) at 2,000K, equilibrium is achieved according to the equation above. In one experiment, the following equilibrium concentrations were measured: [H2]=0.20 M [CO2]=0.30 M [H2O]=[CO]=0.55M a) What

    asked by sara on February 25, 2007
  83. Physics

    A hollow, spherical shell with mass 2.00 kg rolls without slipping down a slope angled at 38.0 degrees. (a) Find the acceleration, the friction force, and the minimum coefficient of fricition needed to prevent slipping. You will find the moment of inertia

    asked by Karla on March 27, 2007
  84. chemisty help

    for the reaction shown, compute the theoretical yield of the product in grams for each of the following initial amounts of reactants. Ti + 2F2 to make TiF4 There are 3 sub questions for this. Help me out with one, then I'll try to figure out the rest.

    asked by Becky on March 1, 2007
  85. Comp.

    Could anyone help me Please.. about the uses of the computer on the following fields. 1.Business 2.Arts and Films 3.Music 4.Engineering 5.Manufacturing 6.Police and Laws Enforces 7.Medicine 8.Education 9.Science and Research 10.Archeology Thanks :-)

    asked by James on June 24, 2007
  86. anatomy

    if you wanted to flex your arm, and both your biceps and triceps contracted simultaneously, what would happen? and where is most of the muscle weight found in humans?

    asked by sara on October 28, 2007
  87. math

    Oregon is about 400 miles from west to east, and 300 miles from north to south. If a map of Oregon is 15 inches tall (from north to south), about how wide is the map? PLEASE HELP AND EXPLAIN IT Set up a proportion: 15/300 (the ratio of inches to miles,

    asked by Aj on January 16, 2007
  88. Chemistry

    What is the pressure (in atmospheres) of the gas inside the container connected to an open-end, mercury-filled manometer as shown in the picture? The atmospheric pressure is 0.95atm. l----l | (G) l | l - --- l Hg l Hg *18cm - - --- Hg Hg HgHgHgHg what

    asked by leo on October 21, 2007
  89. chemistry

    How many moles of solid Ba(NO3)2 should be added to 300 ml of .2 M Fe(NO3)3 to increase the concentration of NO3- ion to 1 M?

    asked by corey on October 3, 2007
  90. physics

    During a rockslide, a 520kg rock slides from rest down a hillside that is 500m long and 300m high. The coefficient of kinetic energy between the rock and the hill surface is .25. a) If the GPE energy U of the rock –Earth system is zero at the bottom of

    asked by Brian on January 10, 2007
  91. Gen chem II

    Calculate the work done when 50.0g of tin dissolves in excess acid at 1.00atm and 25 (degree in celsius) Sn(s)+2H(aq)----- Sn(aq) +H2(g) Assume ideal gas behavior The work done = (pressure)*(increase in volume) The increase in volume is due to the H2 gas

    asked by Farzan on March 5, 2007
  92. Physics

    A train slows down as it rounds a sharp bend, slowing from 90.0km/h to 50.0km/h in the 15.0s that it takes to round the bend. The radius of the curve is 150m. Compute the acceleration at the moment the train speed reaches 50.0km/h. Assume it continues to

    asked by Ryomasa on October 25, 2007
  93. Biology

    The endosymbiont hypothesis offers an explanation for how eukaryptoc cells could have obtained mitochondria and chloroplasts through a symbiotic relationship with prokaryotic cells that changed over time. What structural feature of prokaryotic cells might

    asked by Marisol on February 14, 2007
  94. science

    An outfielder throws a .150 kg baseball at a speed of 40.0 m/s and an initial angle of 30 degrees. What is the kinetic energy of the ball at the highest point of its motion. Work: 0^2=40^2+(.002)(-9.8m/s^2)(d) d=81.6m W=(.150kg)(9.8m/s^2)(cos30)(81.6m)

    asked by Anonymous on October 21, 2007
  95. Physics

    When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 75 kg man just before contact with the ground has a speed of 7.0 m/s. (a) In

    asked by Mary on March 4, 2007
  96. physics

    Please see if I am doing this problem right. A mixture of gasoline vapor and air is placed in an engine cylinder. The piston has an area of 7.4 X 10^-3 m^2 and is displaced inward by 7.2 X 10^-2 M. If 9.5 X 10^5 Pa of pressure is placed on the piston, how

    asked by Anonymous on February 4, 2007
  97. riddle help please

    Why does a sheep scratch himself

    asked by Emanuel on September 17, 2007
  98. CHEM

    What is the hybridization of the central atom in COH2?? Would the correct response, out of the following: a) sp b) sp^2 c) sp^3 d) sp^3d e) sp^3d^2 "e"-> sp^3d^2??

    asked by K on November 26, 2007
  99. Chemistry

    At 40 degrees Celsius, the value of Kw is 2.92 X 10^-14 a.) calculate the [H+] and [OH-] in pure water at 40 degrees celsius b.)what is the pH in pure water at 40 degrees celsius c.)if [OH-] is .18M , what is the pH

    asked by Rebekah on December 21, 2007
  100. Math

    What are irrational, rational, and natural numbers? A rational number is a number that can be written as a ratio. That means it can be written as a fraction, in which both the numerator (the number on top) and the denominator (the number on the bottom) are

    asked by John Christian on January 29, 2007