Questions Asked on
September 26, 2006

  1. Low recovery

    The question is: A student performs a crystallization on an impure sample of biphenyl. The sample weighs 0.5g and contains about 5% impurity. Using his knowledge of solubility, he decides to use benzene as a solvent. The final weight is only 0.02g. Why is

    asked by Sheryl

    A car is traveling 27 m/s when the driver sees a child standing in the road. He takes 0.8 s to react, then steps on the brakes and slows at 8.0 m/s2. How far does the car go before it stops? please help!! Since he's going 27 m/s, and he takes 0.8 s to

    asked by Katelyn
  3. math/unit rate

    please help me find the definition for unit rate. It depends upon what kind of unit. Go to and type in unit rate. There is one source there for hotel unit rates, another for unit rates for the medical field, etc. You may also go to

    asked by hannah
  4. Polarity

    Benzyl alcohol is not a good sovent with which to crystallize fluorenol. The melting point looks okay so I'm assuming that polarity is the problem. Benzyl alcohol looks polar to me because it has an OH but it is only partly soluble in water. Couldn't find

    asked by Sheryl
  5. Buchner funnel

    Question: What would happen if a hot saturated solution were filtered by vacuum filtration using a Buchner funnel? Hint: Cooling will occur. My answer: A Buchner funnel is primarily used to collect a solid from a liquid. When the hot solution cools when

    asked by Sheryl

    A truck is traveling at 16 m/s to the north. The driver of a car, 500 m to the north and traveling south at 25 m/s, puts on the brakes and slows at 3.5 m/s2. Where do they meet? please help!! Let the truck position be X1 and the car position X2, measured

    asked by Katelyn
  7. geometry

    Geometry riddl How did they like the story about towel manufacturing? Also, where can I find geometry worksheets on plane and simple? ? ? ?

    asked by Debra
  8. science

    A swimming pool contains 155m3 of water. If water must be heated from 16C to 32C. How many Joules of heat energy must be supplied? 1 cal=4.184 J Do I need to convert 155m3 to weight? yes. Then mass x 4.184 J/g*c x (Tfinal-Tinitial)= heat energy required.

    asked by Melba
  9. Calc.

    Find the area of the region bounded by the parabola y=x^2, the tangent line to this parabola at (1,1) and the x-axis. I don't really get what this question is asking. It looks like the area of right triangle to me...try the graph, and shade the area under

    asked by Hebe
  10. macro economics

    Suppose that the residents of Veggieland spend all of their income on cauliflower, broccoli, and carrots. In 1998 they buy 100 heads of cauliflower for $200,50 bunches of broccoli for $75, and 500 carrots for $50. In 1999 they buy 75 heads of cauliflower

    asked by shelby

    i have my input output table but i don't know how to complete the sentence inputx / 0/ 1/ 2/ 3/ outputy/ 0/ 1/ 4/ 9/ the question is: does the table represent a function?juatify your answer. ___,because for each____there__ exactly one____. It will be a

    asked by alejandra
  12. cal

    Equations of the tangent lines to hyperbola xy=1 that pass through point (-1,1) I know the graph of y=1/x but not sure about the tangent lines at given point. Are the lines tangent to (1,1) and (-1,-1)? You're correct, the graph is y=1/x, so find y' to get

    asked by Melba
  13. music

    what is an element in music There are a number of musical elements: rhythm, melody, dynamics, harmony, tempo, timbre, articulation, texture and form. You can find definitions for these by clicking on MUSIC under SUBJECTS on the left side of your screen,

    asked by sasha
  14. Math

    FIve years ago Zack would have been three times older than his young brother but five years from now he will only be two times older than his brother. How old is his brother? 25 In other words let x= brothers age so: 3(x-5)=2(x+5) Then 3x-15=2x+10 x=25 I

    asked by Oscar
  15. chem

    What volume of a 0.2 N NaoH solution do you expect to use in order to titrate 25ml (sample out of 250ml) of a 0.200 N oxalic acid solution? heeeelp! Equation is H2C2O4 + 2NaOH==> 2H2O + Na2C2O4 I assume that is 25.00 mL H2C2O4. milliequivalents(meq) NaOH =

    asked by Melba
  16. earth science

    How would you set up a simple experiment to test whether salt crystal growth is affected by temperature It might help if you were clear on how an experiment is set up. An independent variable is the potential stimulus or cause, usually directly manipulated

    asked by teri
  17. history

    physical environment,materials used,stories associated with rampurva bull capital.need to preserve it. Thank you for using the Jiskha Homework Help Forum. The following site will give you more information on the Rampurva Bull Capital. Asian Art and

    asked by chithra
  18. calc

    need to find: lim as x -> 0 of 4(e^2x - 1) / (e^x -1) Try splitting the limit for the numerator and denominator lim lim x->0 4(e^2x-1) (4)x->0 (e^2x-1) ______________ = ________________ lim lim x->0 e^X-1 x->0 e^x-1 Next solve for lim x->0 and simplify

    asked by brian
  19. MATH!!!!

    The CN Tower is 553m high. A person in a boat on Lake Ontario, at a point B due south of the tower, observes the top (T) of the tower at an angle of elevation of 8 degrees. At the same time, another person, at a point C on a bearing {S 85 degrees E } from

    asked by Kaitlin

    A truck is traveling at 16 m/s to the north. The driver of a car, 500 m to the north and traveling south at 25 m/s, puts on the brakes and slows at 3.5 m/s2. Where do they meet? The truck has constant velocity of 16m/s. The car is 500m away, has velocity

    asked by Katelyn
  21. calc

    standard equation of circle concentric with X^2+Y^2-2X-8Y+1=0 and tangent to line 2X-Y=3 Complete the squares to find the center of the circle. X^2+Y^2-2X-8Y+1=0 (x-1)^2+(y-4)^2 - 16 =0 The center is (1,4) and the radius for the given circle is 4. Now find

    asked by Melba
  22. Reading

    What are the elements of a short story and what about charater in the elements? Since this is not my area of expertise, I searched Google under the key words "'Short story' elements" to get these possible sources:

    asked by Sam
  23. English 11, grammar

    my homework is to find pronouns(thats no problem) and then i have to tell whether it's nominative, objective, or possessive. i don't understand any of that, i've tried but my book just doesn't make any sense. nominative = used as subject of the sentence

    asked by Junelle
  24. help

    The CN Tower is 553m high. A person in a boat on Lake Ontario, at a point B due south of the tower, observes the top (T) of the tower at an angle of elevation of 8 degrees. At the same time, another person, at a point C on a bearing {S 85 degrees E } from

    asked by Kaitlin
  25. Entrepreneurship

    Who are two enterpreneur in Accokeek MD. Where can i find a website with a list of enterprener in a certain city.. This site has a list of small businesses in Accokeek, MD. I searched Google for Accokeek and

    asked by Bryan
  26. salem witch hunt

    how long did the salem witch hunt last and what were the dates of the executions and trials? The most famous of the trials was in 1692. The three sites below will give you a schedule of happenings, pictures, diaries, etc. All are excellent sites. w w w.s a

    asked by Justen
  27. third grade science

    what are two jobs of soil? 1 nurients 2 ? keeps the plant in place. my daughter has to write a question about the table that can be answered with one of the choices below. Mark answer and tell why it is correct. SURFACE CAR W/WHEELS INCLINED PLANE a 3n

    asked by briann
  28. Drawing polar curve

    How do you draw a polar curve? For example, r=2+cos2(thetha) You need to plot points where theta varies from 0 to 2pi, unless you have a graphing program (which I do). Your example looks like 2 overlapping circles. so u mean that it can't be drawn by hand?

    asked by J.
  29. science

    what are the three steps in a conclusion in the scientific method? I'm a 9th grader I'm not sure what you are asking. Perhaps a review of the experimental method might be helpful. An independent variable is the potential stimulus or cause, usually directly

    asked by Brandon
  30. eng. language

    i have an essay to write about: if i would be given the liberty to be someone else that day, who would i be??? and how would i spend my time?" this is the question. i will be glad if i get the composition written by someone Well, that's not going to happen

    asked by adwitiya
  31. Physics

    A vector drawn 55 mm long represents a velocity of 25 m/s. How long should you draw a vector to represent a velocity of 17 m/s? please help me!! 55mm is to 25m/s as X is to 17m/s...maybe? thanks..i tried that and the answer was wrong...these questions are

    asked by Katelyn
  32. chemistry - pick a polymer

    I need to pick a polymer for my science project. It has to be organic and preferably simple. Some that are already taken are: polyethene, polystyrene, PVC, polyacrylonitrile, DDT , nylon.. Thanks a lot it has been really hard for me to find something. I

    asked by Annie
  33. chemistry

    Assuming the molor mass of paraffin is 280 g/mol, calculate the # of mols of paraffin burned. Then calculate the heat of combustion of paraffin in kJ/mol I don't think I can help you with the information provided. We need an equation (although we can wing

    asked by dan
  34. biology

    1.identify the 2 major reservoirs of carbon dioxide into the atmosphere 2.what are the forms in which carbonis found n the oceans Since this is not my area of expertise, I searched Google under the key words "carbon dioxide reservoirs atmosphere" to get

    asked by celina
  35. calculus

    find the first derivative of the following functions: y=[((x^2)-4)/(x+2)] g(x)=[(x+1)/(x^1/2)] Let's make like easier by doing some algebra first. y=((x^2)-4)/(x+2) = x-2 dy/dx = 1 g(x)=[(x+1)/(x^1/2)] = x^(1/2) - x^-1/2) dg/dx = (1/2) x^-1/2 + (1/2)x^-3/2

    asked by jarold
  36. MATH

    MAKE R the subject of the formulaq........ I =(mne) devide by (mR+nr)...........Its N2 math can u help? It's not at all clear to me what your question is, what does this mean? "MAKE R the subject of the formulaq........" In this part, are we to take

    asked by MICHELLE
  37. definition

    What does environmental studies mean Environmental studies is the systematic study of human interaction with their natural environment. It is a broad field of study that includes, in addition to the natural environment, built environments, social

    asked by short attention span
  38. calc

    standard equations of circles that have centers on line 5x-2y=-21 and are tangent to both axis. Any ideas?? First express the line as in point slope form y=(5/2)x - 21/2 The center must be on the line, so it is a point expressed as (x,(5/2)x - 21/2) In

    asked by Melba
  39. math

    538,605 the eight is under lined. the question is use the place vaule. Round each nimber to the place vaule of the under lined digit -+5=13 The 8 is in the thousand's place. Is the number closer to 539,000 or 538,000? If the digit following the underlined

    asked by Genesis
  40. Anglo America

    What two countrys are owned by Anglo America? The Anglo American Company owns coal fields in South Africa and Liberia. Is this what you are looking for? human features in anglo-america

    asked by Melissa
  41. economics

    5.1998 Price Quantity cauliflower $200

    asked by shelby
  42. eceonomic

    The isoquant line is described on this forms: a)y=[x1/2 + x1/2]2 (1/2 should be mark as upper quartile) b)y=[x12 + x22]1/2 (x1 as lower quartile and 2 upper for first x and same for x22). The question is how to draw the isoquent line and how to explain the

    asked by Sigmund
  43. english

    I need a sentence with sentence opening, sentence closing, and subject/verb splitting participial phrases

    asked by nique from dallas
  44. economics help!!!

    5.1998 Price Quantity cauliflower $200 100 broccoli $ 75 50 carrots $ 50 500 Total $325 Weight of each good weight for cauliflower 200/325= 0.61532 weight for broccoli 75/325= 0.2307692 weight for carrots 50/325=0.1538461 Prices in the base year

    asked by shelby
  45. Calculus

    f(x)=x^2 - 5x +7 and g(x) 3/x 1) Indicate points of intersection 2) compute the area enclosed by the graphs of f(x) and g(x). 1) (1, 3) , (3, 1) 2)Area = ∫ [1 to 3] [(3/x) - (x^2 - 5x + 7)] dx = [3 ln x - (1/3)x^3 + (5/2)x^2 - 7x = 3 ln 3 - 8/3 am i

    asked by Rain
  46. math

    how many square inches are in a square foot A square foot has 12 inches on each side. To find the number of square inches, multiply 12 x 12. You can also go to and type in 1 square foot to square inches and press enter.

    asked by krissy
  47. Spanish

    Hey, I have to write a 200-250 word paper on my life in the future as a famous person. I am in a magazine, and i have to write about how my life, career, and family are. I would appreciate it if someone could proofread my Spanish. Thanks! SPANISH: La

    asked by Mark
  48. Melting point

    Could you tell me what the melting point for a crystallized sulfanamide is? Also, we will have to determine the m.p. of an impure sulfanamide. Any idea of a temperature range for that? Will it be higher of lower? Probably hard to tell since I don't know

    asked by Sheryl
  49. biology

    what processes in the transparency release dioxide into the atmosphere See the sources in my response to your other post. I hope this helps. Thanks for asking.

    asked by celina
  50. third grade social studies

    what is a capital resource? Something that can be used to make goods or services. I need information on government representatives, and senetors who is he the body of water that the romans depended on for trading and traveling.

    asked by samm
  51. Environment

    What is Arsenic pollution? I assume you are talking about higher than normal amounts of arsenic in air/water/etc. Arsenic need not be in the metal form (elemental form) to be toxic. Most, if not all, compounds of arsenic are toxic at some level. As2O3 and

    asked by Natasha
  52. economics

    year nominal GDP GDP deflator (billions) (based year 1992) 1993 725 101.2 1994 762 102.4 Are these answeres correct???? 4.a) The growth rate of nominal income between 1993 and 1994 is 5.10% (725-762)/725*100=5.10% b) The growth rate of the GDP deflator

    asked by shelby
  53. chemistry

    What instrument is used to determine the mass and relative ambuandaces of small atomic particles? You may be thinking of the mass spectrometer. I'm not sure how small you are talking about but the mass spec is used to determine atomic masses and relative

    asked by carter
  54. Marketing

    Need help unscrambling the following letters to form a word. coppscryhsghai

    asked by Joe
  55. Math

    How do you solve a double sided variable? I am not sure what you are asking. Even so, since this is not my area of expertise, I searched Google under the key words "'double sided variable' math" to get this possible source:

    asked by Sammi
  56. Engines

    How do i find total displacement in in^3/min if i have the bore and stroke and and rpm and number of cylinder. i can calculate piston and engine displacement and compression ratios but just not sure about TOTAL displacement and the rpms?

    asked by Matt
  57. heeelp

    Find two examples of cities which once had been secondary producers in the middle of the city. What kinds of industry where once important in each of these city centres? Find out what kind of production has often replaced them. What do you think are the

    asked by galassia
  58. math help please

    a +p - x+y - --- b z ok its a over b plus p minus x plus y over z So you mean a/b + p - x + y/z ? and what is supposed to be done with this expression considering there are 6 different variables?? remember how to substract fractions? Common denominator

    asked by cassii
  59. Accounting

    Hi i need help with the following transactions. Right now we are learning about the accrual basis of accounting. 1.Rent Payments included $750 per month rental fee and a $900 deposit that is refundable at the end of the 2 yr lease. 2.The company manager

    asked by F
  60. science

    What is the point at witch gas changes into a liquid? The same as the point at which liquid changes to a vapor; i.e., the boiling point. It is sometimes called the condensation point, also. Temperature, wise, however, it is the same T.

    asked by rach
  61. Geography

    If a country is in dire need, as in Africa for example, why can't that country's currency production be increased to pay for such things? Who decides how much the Canadian mint makes, and why can it not make money to meet provincial needs? Unrestricted

    asked by Jenessa
  62. science

    What type of cells are infected by measles Since this is not my area of expertise, I searched Google under the key words " measle infection cells" to get these possible sources:

    asked by nique from dallas
  63. math

    5n-34>7(n-2) You might start by using the distributive property on the right hand side to get 7n-14, then subtact the 5n from both sides and add 14 to both sides.

    asked by jmoney
  64. Algerbra

    solve for x ac+x=xy have all terms with x on one side ac=xy-x take x as common factor ac=x(y-1) now solve for x 25a^2 - 9b^4 can u please help me solve and check these equations

    asked by Mark
  65. Polar coordinates

    I need some help on this Calculus question about polar coordinates. Consider a pasture bordering on a straight river. At 2m from the river, a goat is tied to a pole with a 4m long rope. What is the area of grass that the goat can graze? There are a couple

    asked by Rain
  66. math

    is this correct? given: f(x)=x/x+1 find: f(2+h) = f(2) + f(h) = 2/3 + h/h+1 To find f(2+h) replace it into original equation wherever there is x f(2+h)= 2+h/2+h+1 = 2+h/3+h

    asked by hawkstar