Questions Asked on
February 24, 2012

  1. Chemistry 101

    if 95j of heat is added to a pure gold coin with a mass of 16 grams, what is its temperature change? Specific heat capacity of gold is 0.128 j/g degrees C.

    asked by Haley
  2. physics

    . An inquisitive physics student and mountain climber climbs a 50.0-m cliff that overhangs a calm pool of water. He throws two stones vertically downward, 1.00 s apart, and observes that they cause a single splash. The first stone has an initial speed of

    asked by ai
  3. statistics

    A student scored 84 points on a test where the mean score was 79 and the standard deviation was 4. Find the student's z score, rounded to 2 decimal places

    asked by RGCLARK
  4. statistics

    A scatter plot would be useful for A. Showing the relative number of sales of four different brands of blank DVDs B. Showing the trend of sales, over time, of five different brands of blank DVDs C. Showing the relationship between the sales of blank CDs

    asked by RGCLARK
  5. chemistry

    Separate this redox reaction into its component half-reactions. O2 + 2Zn -->2ZnO

    asked by Anonymous
  6. chemistry

    a quantity of gas is collected over water at 15C. The manometer indicated a pressure of 24.0kPa. what would be the pressure of the dry gas?

    asked by garrett
  7. physics

    two charged bodies exert a force of 86N on each other. If they are moved so that they are 6 times farther apart, what is the new force that they will exert on each other?

    asked by Anonymous
  8. chemistry

    The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 6.35-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing agent so that all the

    asked by Anonymous
  9. 3 grade english

    singular and plural pronouns direction revise each sentence. replace the underlined words with sigular or plural pronouns. 1- some people thought of a new sport, and the sport became popular. in this sentence the word underline is (the sport) my son write

    asked by dw
  10. chemistry

    The reaction: A + 3 B = D + F was studied and the following mechanism was finally determined A + B = C (fast) C + B = D + E (slow) E + B = F (very fast) The step with largest activation energy is a. the first step b. the second step c. the third step d.

    asked by bob
  11. Math

    If paul pays the newspaper company 70% of what he collects how much would he keep for himself in a month when he collected $450.00

    asked by Yazmin
  12. chemistry

    How many liters of pure oxygen at STP is consumed by a human being in 24 hours if the human body requires daily energy that comes from metabolizing 816 grams of sucrose (C12H22O11)? C12H22O11(s ) + 12 O2(g) => 12 CO2(g)+11 H2O

    asked by garrett
  13. more math needed

    You have a 70% dextrose solution. How many grams of dextrose are in 400ml?

    asked by Vicki
  14. chemistry

    Separate this redox reaction into its component half-reactions. Cl2 + 2Na --> 2NaCl

    asked by Anonymous
  15. math

    A pie chart of total number of students in a school has a sector 35degree representing many students are there in the school altogether?

    asked by Tony
  16. physics

    A person of mass 84.5 kg is initially at rest on the edge of a large stationary platform of mass 150 kg, supported by frictionless wheels on a horizontal surface. The person jumps off the platform, traveling a horizontal distance of 1.00 m while falling a

    asked by John
  17. Healthcare Finance

    You are considering starting a walk-in clinic. Your financial projections for the first year of operations are as follows: Revenues (10,000 visits) $400,000 Wages and benefits 220,000 Rent 5,000 Depreciation 30,000 Utilities 2,500 Medical Supplies 50,000

    asked by anonymouscoward
  18. chemistry

    For a certain chemical reaction, the rate constant at 250.0 °C is 0.00383 s-1 and the activation energy is 22.40 kilojoules. Calculate the value of the rate constant at 335.0 °C. a. 0.00513 s-1 b. 0.00946 s-1 c. 0.00787 s-1 d. 0.0224 s-1 e. 0.000640 s-1

    asked by bob
  19. Math

    Kelly plans to put her graduation money into an account and leave it there for 4 years while she goes to college. She receives $750 in graduation money and she puts it into an account that earns 4.25% interest compounded semi-annually. How much will be in

    asked by Anonymous
  20. Physics

    The force exerted by the wind on the sails of a sailboat is Fsail = 440 N north. The water exerts a force of Fkeel = 160 N east. If the boat (including its crew) has a mass of 250 kg, what are the magnitude and direction of its acceleration?

    asked by Gregg
  21. chemistry

    For a one step reaction, the activation energy for the forward reaction is 40.0 kJ/mol and the enthalpy of reaction is -20.0 kJ /mol. Which statement below is true? a. The activation energy of the forward reaction would be affected to a greater extent than

    asked by bob
  22. chemistry

    is the low solubility of KHT a result of an unfavorable delta H or an unfavorable delta S value

    asked by Anonymous
  23. chemistry

    Al(NO3)3 + NH3 --> ?

    asked by Jimmy
  24. Physics

    What is the total charge of all the electrons in a 13 kg bar of silver? (Silver has 47 electrons per atom and an atomic mass of 108 u.)

    asked by Millie
  25. chemistry

    For a particular chemical reaction, the rate constant at 30.0 °C is 1.38 X 10-4 L mol-1 s-1, while the value at 49.0 °C is 1.21 X 10-3 L mol-1 s-1 . What is the activation energy for this reaction? a. 92.8 kJ b. 200 kJ c. 40.4 kJ d. 343 kJ e. 56.4 kJ ln

    asked by bob
  26. chemistry

    calculate the freezing point of 12.0g FeCl3 in 142g water...

    asked by globamabob

    You ride your bike along a straight line from your house to a store 1030 m away. On your way back, you stop at a friend's house which is halfway between your house and the store. a) What is your displacement? b) What is the total distance traveled? c)

    asked by MARÝA
  28. Physics

    If the angle decreases what will happen to the tension? Please explain why.

    asked by Anonymous
  29. Math

    Match each ratio in the first row with an equivalent ratio from the second row if angle A plus angle B = 90 degrees. SinA CosA TanA CscA SecA CotA SinB CosB TanB CscB SecB CotB Pleaseeee help!!

    asked by krista
  30. Chemistry

    The decomposition of hydrogen peroxide in solution and in the presence of iodide ion was studied in laboratory, and the following mechanism proposed based on the experimental data. H2O2 + I - = H2O + IO - (slow) H2O2 + IO - = H2O + O2 + I - (fast) Which

    asked by Mohamed
  31. physics

    What are the factors that affect the quantity of heat needed to raise the temperature of a substance?

    asked by jaquie
  32. math

    the straight L has gradient 3 and passes through the point A(-6,4). a) find an equation for L in the form y=mx+c b) straight line R has the equation in the form of -7y+x+14=0. Given that R crosses the y-axis at the point B and intersects L at the point C,

    asked by aminath
  33. Physics

    A point charge (m = 1.0 g) at the end of an insulating string of length L = 51 cm (Fig. 16-66) is observed to be in equilibrium in a uniform horizontal electric field of E = 9200 N/C, when the pendulum's position is as shown in Fig. 16-66, with the charge

    asked by Millie
  34. chemistry

    The decomposition of hydrogen peroxide in solution and in the presence of iodide ion was studied in laboratory, and the following mechanism proposed based on the experimental data. H2O2 + I - = H2O + IO - (slow) H2O2 + IO - = H2O + O2 + I - (fast) Which

    asked by bob
  35. math

    how do you format hours/day-percentage of time spent during an 8 hour work day ?

    asked by Tiffany
  36. chemistry

    The equation A + 2 B = C + D describes an elementary reaction, which takes place in a single step. Thus, the rate law must be a. rate = k(A]2 b. rate = k(B]2 c. rate = k(A][B] d. rate = k(A][B]2 e. none of the above represents the rate law for this

    asked by bob
  37. chemistry

    The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq)

    asked by Katie
  38. Math

    A man walks one mile east, then he walks one mile northeast and then he walks one mile east. How far is he from his initial position?

    asked by Bailee
  39. Physics

    Calculate the resistance per unit length of a nichrome wire, which has a radius of 0.436 mm. The resistivity of nichrome is 1.5×10−6 Ω·m. Answer in units of Ω/m If a potential difference of 20 V is maintained across a 3.7 m length of the nichrome

    asked by Kudo
  40. Chemistry

    How many grams of carbon dioxide are produced in C3H8+5O2 -> 3CO2+4H2O

    asked by Lily
  41. chemistry

    A particular reaction has an activation energy of 51.6 kJ/mol-rxn. How much faster is the reaction at 50 degrees C versus 25 degrees C? a. 2 times b. 5 times c. 3 times d. half as fast d. 20% as fast help

    asked by bob
  42. Chemistry(Please check)

    1) The reaction: A + 3B = D + F was studied and the following mechanism was finally determined A+B=C (fast) C+B=D+E (slow) E+B=F (very fast) Which step has the largest activation energy? I chose the second step because it is slow and should have the most

    asked by Hannah
  43. Chemistry

    Balance the redox equation by oxidation number method: Cr2O7 2- + Br- + H+ = Cr 3+ + Br + H2O Please help!

    asked by Sarah
  44. English 3

    Why are stories and poems about the "realms of darkness" so popular with many readers? Thanks -MC

    asked by mysterychicken
  45. physics

    A horizontal wire of length 0.78 m, carrying a current of 6.8 A, is placed in a uniform external magnetic field. When the wire is horizontal, it experiences no magnetic force. When the wire is tilted upward at an angle of 20°, it experiences a magnetic

    asked by Anonymous
  46. ethics

    This is the question i was asked, "The things that will destroy us are: politics without principle; pleasure without conscience; wealth without work; knowledge without character; business without morality; science without humanity; and worship without

    asked by leanne
  47. Calc 1

    A farmer with 700 ft of fencing wants to enclose a rectangular area and then divide it into four pens with fencing parallel to one side of the rectangle. What is the largest possible total area of the four pens?

    asked by Grant
  48. Physics - grade 11

    The speed of light of a plastic is 1.4x10^8. What is the index of refraction in the plastic?

    asked by crystal
  49. chemistry

    In a particular redox reaction, Cr is oxidized to CrO42– and Cu2 is reduced to Cu . Complete and balance the equation for this reaction in acidic solution. Phases are optional. Cr + Cu2+ = CrO42- + Cu+

    asked by Anonymous
  50. Bussiness

    The market for carrots is comprised of two segments: fresh market carrots, which have excellent, uniform color and a small core, and processing carrots, which are larger than fresh market carrots but still have good flavor, color, and sweetness. Annual

    asked by Ricky
  51. Chemistry

    A + 2 B = C + D describes an elementary reaction, which takes place in a single step. Thus, the rate law must be a) rate = k (A)^2 b) rate = k (B)^2 c) rate = k (A) (B) d) rate = k (A) (B)^2 I think its D because there are 2 moles of B and 1 mole of A. Do

    asked by Mohamed
  52. physics

    The acceleration of a particle moving only on a horizontal plane is given by a= 3ti +4tj, where a is in meters per second-squared and t is in seconds. At t = 0s, the position vector r= (20.0 m)i + (40.0 m)j locates the particle, which then has the velocity

    asked by amy
  53. calculus


    asked by Anonymous
  54. physics

    The acceleration of a particle moving only on a horizontal plane is given by a= 3ti +4tj, where a is in meters per second-squared and t is in seconds. At t = 0s, the position vector r= (20.0 m)i + (40.0 m)j locates the particle, which then has the velocity

    asked by amy
  55. US HIstory

    In what ways was dulles's policy of brinkmanship different from truman's cold war policies? Thanks

    asked by Sarah
  56. physics

    A 90 cm length of steel wire with a diameter of 0.5 mm is stretched between the inside walls of an oven the wire is just taut with no tension when the temperature in the oven is 250 °C. What is the the tension force in the wire when the oven cools to a

    asked by sand
  57. math

    after passing therough a material t centimeters thick, the intensity I(t) of a light beam is given by I(t) =(4^-ct)Io, where Io is the initial intensity and c is a constant called the absorption factor. Ocean water absorbs light with an absorption factor

    asked by Suzie
  58. physics

    The temperature in a room is kept at a constant 20 °C but the humidity is only 20%. If the room has a volume of 30m³, and the room’s door and windows closed, how many kilograms of water must be put into the vaporizer to increase the humidity from 20%

    asked by sand
  59. science

    A 70 liter tank containing an ideal gas at a pressure of 40 atmospheres is connected by a valve to a 30 liter tank of an ideal gas at 70 atmospheres. The valve is opened slowly and the gases in two tanks mix. Assuming the temperature throughout is

    asked by Stephanie
  60. science

    A piston pump containing 2 liters of nitrogen gas at 3000 psia (absolute) pressure empties its entire contents into a 10 liter pressure container. Before the transfer of gas the 10 liter container already contained nitrogen gas at 100 psia (absolute)

    asked by Stephanie
  61. Recheck-Essay

    By studying in the USA, I believe that I am not only getting an internationally recognized education, but also a thrifty one. My decision to study here will help me become independent. In addition, the money I save by studying here will eventually help me

    asked by Hero
  62. Psychiatry

    Application of psycology in developing country

    asked by Bayush
  63. Stem

    What controls move robotic arm?

    asked by Dj John
  64. math

    The 5th grade marching band includes boys & girls. There are 28 boys in a marching band. The boys are 7/10 of the students in the marching band. What fraction of students in the marching band girls? What is the total number of students in the marching

    asked by nina
  65. physics

    If the mass of an object was 0.500 kg and it started from rest, then the object's final velocity at the end of 0.86 seconds is ?

    asked by sarah
  66. Calculus

    Evaluate the limit: lim ((7-x)^2)-9 / 4-x x->4

    asked by Labiba
  67. statistics

    If the means for our groups on calories consumed a day were Group A = 2000, Group B = 2500, and Group C = 3000 could we just assume that all of the groups had statistically different means? How could we determine which groups were significantly different

    asked by pat
  68. english 3

    11. Which one of the following statements is not true about the president Ratcliffe portrayed in The General History? He wasn't very popular. His judgment was weak in times of peril. He voluntarily turned over leadership to John Smith. He was greedy and

    asked by helpp
  69. chemistry

    Calculate the number of moles in each of the following: 0.150 g of salicylic acid 0.30 mL of acetic anhydride (density = 1.08 g/mL)

    asked by Pat
  70. Chemistry

    This is probably easier then my making it but... Calculate the ph of a forming acid solution that contains 1.35% forming acid by mass. Assume a density of 1.01g/ml for the solution.

    asked by L.Bianchessi
  71. Chemistry

    What is the [H3O] concentration in a 1.0M CH3COONa solution? (The Ka for CH3COONa is 2.0*10-5.)

    asked by Brianna
  72. math

    find x such that (x,7) is 10 units from (-4,1)

    asked by shain
  73. Physics

    Any assistance explaining how to work this would be great! The force exerted by the wind on the sails of a sailboat is Fsail = 480 N north. The water exerts a force of Fkeel = 240 N east. If the boat (including its crew) has a mass of 350 kg, what are the

    asked by Student
  74. math

    Nick is writing the 4 letters in his name in different orders. In how many orders can he put the letters?

    asked by unknown
  75. math

    Keith, Annie, Elizabeth, and Marcus are taking a picture. How many different ways can the friends stand in a horizontal line?

    asked by unknown
  76. US Government

    What should be the goals of the US government today? I have to write an essay with this very question but I need help to formulate at least 4 different topics that the US Government should focus on.

    asked by Sam
  77. chemistry

    Explain how you would prepare a saturated aqueous solution of table sugar. Heat the solution to near its boiling point. With stirring, add table sugar to water. Keep adding sugar until no more dissolves. Allow the solution to cool. With stirring, add table

    asked by krystal
  78. Biology

    Is nail sulcus and nail fold the same thing?

    asked by Lil
  79. math

    A box holds 2 blue marbles and 6 red marbles. How many and what color marbles could you remove from the bag to make the probability of picking red 1/2?

    asked by unknown
  80. math

    what is the process for solving the following question? John is 72 inches tall and casts a 40 inch shadow. A monument casts a 24 foot shadow. How tall is the monument?

    asked by n
  81. Orgo

    What volume of 1.20 M nitric acid is needed to convert 5.5g of m-chlorophenol to 3-chloro-2,6-dinitrophenol? I So far I have converted the 5.5g chlorophenol to mols and I got .043 mol. I know Volume * Molarity (1.2M)=moles. At this point I am stuck.

    asked by Sam
  82. books

    In "Touching Spirit Bear," the book, I have to answer these questions. 1. Why does Cole think the bear attacked him? 2. In what way has Cole's mother changed? 3. What happened to Cole's dad when he was a child? 4. Who is the surprise visitor to Circle

    asked by Alexis Herda
  83. Chemistry

    I need to convert these 5 values of time into minutes. 1)1.07 1min 7 seconds 2) 6.00 3) 5.02 4) 1.32 5) 25.5 seconds The example that was given for conversion was 5 min 40 sec = 5.67min These are the values that I got after dividing by 60. 1) 1.07 =

    asked by Hannah
  84. college algebra

    Given f(x)= 3x^2+x-30 and g(x)=x-3 find f(x)-g(x)

    asked by melissa
  85. physics

    A 5.0 {\rm nC} point charge sits at x = 0. At the same time, a 3100 {\rm N/C} uniform electric field (created by distant source charges) points in the positive x-direction.

    asked by Anonymous
  86. social studies

    From the point of view of an environmentalist, which is probably the most significant argument against offshore drilling for oil?

    asked by Anonymous
  87. college algebra

    Given f(x)=sqrt x+4 and g(x)= 1/x find (fog)(x)

    asked by Missy
  88. Physics

    A bowling ball weighing 67.0 N initially moves at a speed of 4.80 m/s. How long must a force of 54.5 N be applied to the ball to stop it?

    asked by Anonymous
  89. physics

    Two forces are applied to a car in an effort to move it, as shown in the following figure, where F1 = 416 N and F2 = 363 N. (Assume up and to the right as positive directions.)

    asked by Anonymous
  90. calculus

    A 29-ft chain with mass density 3 lb/ft is initially coiled on the ground. How much work is performed in lifting the chain so that it is fully extended (and one end touches the ground).

    asked by Sara
  91. Physics

    A rubber ball of mass 41.5 g is dropped from a height of 1.75 m onto a floor. The velocity of the ball is reversed by the collision with the floor, and the ball rebounds to a height of 1.55 m. What impulse was applied to the ball during the collision?

    asked by Anonymous
  92. Calculus

    find f'(x) if f(x)= (cosx)^sinx

    asked by Jesse Stone
  93. Calculus

    find f'(x) if f(x)=x^2*e^x*(3x-1)^3

    asked by Johnathan
  94. chemistry

    A catalyst alters the rate of a reaction by a. changing the products in the reaction. b. increasing the activation for the reaction. c. always providing a surface on which the molecules react. d. providing an alternate pathway for the reaction. e.

    asked by bob
  95. math

    how many feet in a dozen

    asked by sami
  96. chemistry

    If the reaction Cl2 (g) + O3 (g) = Cl2O (g) + O2 (g) occurred in just two steps, what would be the overall order of the reaction be? a. 1 b. 2 c. 3 d. 4 e. not possible to determine from the information given

    asked by bob
  97. Chemistry

    I had to perform an experiment for rate of reaction. I have to calculate the concentration of Na2S2O3 in the reaction solutions based on the volume used in each reaction flask and the total volume calculated. There were five flasks used and for all 5 of

    asked by Hannah
  98. History

    Is there any "European bias or bias" in this article? To obtain the necessaries of life, they (he Indians of Arcadia) endure cold and hunger in an extraordianry manner. During eight or ten days, if the necessity is imposed on them, they will follow the

    asked by Cara
  99. Calculus

    I could really use the help on this as soon as possible. what is the slope of the line tangent to the curve (/x)^2 at point (4,16)

    asked by Jesse Stone
  100. math

    Solve variation problem if m varies jointly as z and p, and m=10 when z=2 and p=7.5, find m when z=5 and p=7

    asked by Anne
  101. Business

    " performance can't be measured , so any effort to link pay with performance is a fantasy. Difeerence in performances are often caused by the system, which means the organization ends up rewarding the circumstances. It's the same thing as rewarding the

    asked by Stephanie
  102. physics

    Find the acceleration of the block of mass M = 4.79 kg (m = 4.03) (KE = 0.1)

    asked by John
  103. Business

    Regarding the question I posted about performance if you agree or don't agree why?

    asked by Stephanie
  104. physics

    Find the gravitational force exerted by a 0.515 kg mass on a 0.108 kg mass 1.94 m away.

    asked by John
  105. Business

    Describe five different bases (other than productivity) by which organizations can compensate employees. Based on your knowledge and experience, do you think productivity is the basis most used in practice?

    asked by Giggles
  106. plz help math

    solve variation problem. if y varies directly as x and inversely as m^2 and r^2 and y=5/3 when x=1, m=2 and r=3, find y when x=3, m=1 and r=8

    asked by Anonymous
  107. music read

    After completing your study reading, it is vital that you complete which of the following steps?

    asked by Anonymous
  108. Embedded Software

    How would you write a linux program to read data from a joystick, and turn that data into a command that is pushed onto the queue?

    asked by Adhi
  109. algebra

    solve by the substitution method. 6x+3y=-21 -4x+y=41

    asked by kim
  110. math

    a perso increases the number of tosses of a fair coin the actual number of heads will get farther and farther away from the number of tosses divided by 2

    asked by marie
  111. PHYSÝCS

    At the end of the spring term, a high school physics class celebrates by shooting a bundle of exam papers into the town landfill with a homemade catapult. They aim for a point that is 31.1 m away and at the same height from which the catapult releases the

    asked by MARÝA
  112. PHYSÝCS

    You are walking on a moving walkway in the airport. The length of the walkway is 40.1 m. If your velocity relative to the walkway is 2.41 m/s, and the walkway moves with a velocity of 1.59 m/s, how long will it take you to reach the other end of the

    asked by MARÝA
  113. PHYSÝCS

    The position of a particle moving along the x-axis is given by x = 3.49t2 – 2.21t3, where x is in meters and t is in seconds. What is the position of the particle when it achieves its maximum speed in the positive x-direction?

    asked by MARÝA
  114. Math

    x+y=5 x-y=3 Please help me solve this system of equation and show your work thanks

    asked by Kim
  115. PHYSICS-electricity & magnetism

    An electric field exits inside a fluorescent tube of diameter 3.00cm. In one second, 2.00x10^18 electrons and 0.50x10^18 positive ions pass through a certain cross section. What is the current in the tube?

    asked by Brandon
  116. criminal procedure

    In which areas of search and seizure do you feel that the courts have not gone far enough? In which areas of search and seizures do you feel that the courts have not gone far enough? suport your position. Use actual court cases to support position.

    asked by marie
  117. chemistry

    Al(NO3)3 + NH3 --> ?

    asked by Lucas
  118. american history

    I nee help revising my essay here it is This is what my general view on American History. Well let me tell you it’s a course that we all have to take in high school to graduate. In school we are confronted with American History, state History and general

    asked by connie
  119. Biology

    Denny, who is allergic to wool, accidentally wears a scarf that is 50% wool. one hour later, after removing the scarf, she finds that the skin around her neck is red and swollen. Explain what has happened to her. (Our unit is Blood and immunity)

    asked by Soar
  120. psychology

    NREM sleep is characterized by

    asked by Anonymous
  121. physics

    An American standard analog television picture (non-HDTV), also known as NTSC, is composed of approximately 485 horizontal lines of varying light intensity. Assume your ability to resolve the lines is limited only by the Rayleigh criterion, the pupils of

    asked by mina
  122. Java

    create a java program that accepts students names, and test scores from a file, and displays theri name, average score and letter grade to the screen.

    asked by Big Daddy
  123. Statistics

    For sample mean x = 150, sample size n = 36 and sample standard deviation s = 40 find 80% confidence interval for population mean. Population standard deviation is not known

    asked by Tina
  124. physics

    an 84 kg fisherman jumps for a dock into a 122 kg rowboat at rest on the westside on the dock. if the velocity of the fishermen is 4.8 m/s to the west as he leaves the dock what is the final velocity of the fishermen and the boat?

    asked by Anonymous
  125. English

    Writeacher, I need to write phrasal verbs related to work. I wonder if you could help me. I wanted to include them in a story but some phrasal verbs are more used in dialogues. 1) My mum works as a secretary for the personnel manager in the Ferrero firm.

    asked by Henry2
  126. Chemistry

    An aqueous sugar solution is formed by adding 50.1 g sucrose (C12H22O11) to 200.0 g water. What is the boiling point (in Celsius) of this sugar solution (this is NOT the ΔTb). Kb H2O = 0.51 Celsius/m

    asked by amy
  127. Chemistry

    An aqueous salt solution is formed by adding 11.67 g sodium sulfate (solute) to water (solvent). What mass (in g) of water is used if the freezing point of the solution is -12.9 Farenheit. Kf H2O = 1.86 Celsius/m

    asked by jenny
  128. algebra


    asked by Sasha
  129. chemistry

    Cocaine is a non-electrolyte that has a molecular weight of 303.4 g/mole. How many grams must be dissolved in 25.0 mL of Chloroform (density = 1.484 g/mL) to raise its boiling point to 65.5 Celsius? The boiling point of pure Chloroform is 61.2 Celsius. Kb

    asked by anna
  130. Chemistry Help PLEASE!!

    I don't know how to do this question, I understand we have to use ICE but I keep getting the wrong answer when I solve for x, it's just not working for me. Consider the following reaction: A(g) -> 2B (g) Find the equilibrium partial pressures of A and B

    asked by Student
  131. social studies

    A study of the causes of the American Revolution of 1776, the French Revolution of 1789, and the Russian Revolution of 1917 best supports the generalization that revolution is most likely to occur when?

    asked by Anonymous
  132. probability problem

    A box contains 6 green, 8 red, 5 yellow, and 10 blue marbles. Four marbles are drawn from the box at the same time. a) What is the probability that all four marbles are the same color? b) What is the probability that none of the marbles is blue? c) What is

    asked by Sam
  133. Chemistry(Please check)

    1) A catalyst alters the rate of a reaction by a. changing the products in the reaction. b. increasing the activation for the reaction. c. always providing a surface on which the molecules react. d. providing an alternate pathway for the reaction. e.

    asked by Hannah
  134. CHEM

    How does the neutron to proton ratio affect the stability of an atomic nucleus ?

    asked by NILA
  135. math

    The surface area of any shape is expressed in:

    asked by isaac
  136. math

    What is the surface area of a circle that has a diameter of 14 inches?

    asked by isaac
  137. math

    What is the surface area of a circle that has a diameter of 14 inches?

    asked by isaac
  138. computer

    To all computer programmer or people know or use computer programming. what tags can we use to connect the comment of the web page to your email. thanks to all of you to help me...

    asked by shiela
  139. math

    Write expression for the other five trigonometric ratios for each acute angle: A) cscƒÆ=a/b B) secƒÀ= x+1/x-1, x‚1

    asked by Christine
  140. Calculus

    The fuel efficiency, E, in litres per 100 km, for a car driven at speed v, in km/h is E(v)=1600v/(v^2+6400) a) determine the legal speed that will maximize the fuel efficiency using speed limit of 50 km/h

    asked by Jake
  141. Calculus

    what is the slope of the line tangent to the curve (/x)^2 at point (4,16) * (/x)= the squareroot of x

    asked by Jesse Stone
  142. math

    int( absolute(x-1) + sqrt(9-x) ) Hint: you may interpret the integral as an area.

    asked by Calculas
  143. speech

    I am looking for an attention getter for my imformative speech about dog-human communication, In the speech, I am going to be talking about verbal and non verbal dog behaviors and then how dogs repond to human verbal and non verbal behaviors. I was

    asked by rebekah
  144. statistics research

    What proportion of adults use between 15 and 23 gallons of gas per week if it is normally distributed with a mean of 16 gallons and a standard deviation of 5 gallons?

    asked by Lauren
  145. physics

    A 1.50 103-kg car starts from rest and accelerates uniformly to 18.5 m/s in 11.3 s. Assume that air resistance remains constant at 400 N during this time. (a) Find the average power developed by the engine. 1 W (b) Find the instantaneous power output of

    asked by Mark
  146. physics please help

    one kilwatt/hour (kWh) is the amount of work or energy generated when one kilowatt of power is supplied fr a time of one hour. a kilowatt/hour is the unit of energy used by power companies when figuring your electric bill. determine the number of joules of

    asked by taylor
  147. Statistics

    How do you find the proportion bewtween two numbers, for example, proportion of people drink between 18 and 26 gallons of water per week?

    asked by Laurena
  148. math

    If you need 240 oz of paint to cover 1200 in. How much paint do you need to cover 2000 in.?

    asked by Lindsey
  149. AP US History (Help Required ASAP)

    Explain the rise of the republicans and the international challenges faced following world war I?

    asked by Amy
  150. chemistry

    A quantity of gas has a volume of 121 L when confined under a pressure of 2.50 atm at a temperature of 20.0 C. At what pressure will its volume be 30.0 L at 25.0 C?

    asked by garrett
  151. chemistry

    what volume does 2.5 moles of carbon monoxide occupy at 50.5 kPa pressure and 20.0 C?

    asked by garrett
  152. physics please help

    the floors in a typical house are separated by a vertical distance of approximately 8.0 ft. a teenager (1.0x 10^2 lb) climbs the stairs between floors at a steady speed. find the power necessary to accomplish this if the stairs are climbed in (a) 10.0 s

    asked by taylor
  153. Math

    Solve triangle ABC if b = 10, c = 9.1, and C = 53.6 degrees. How many solutions are there? First Solution:What are angle A and B and Side a. Second Solution: What are angle A and B and Side a. Thanks!

    asked by Rosetano
  154. american history

    Ineed help revising my assignment

    asked by connie
  155. Geology

    Is the distribution of geologic activity clumped, random, uniform, or some other pattern? Explain\ Is the distribution of geologic activity clumped, random, uniform, or some other pattern? Explain

    asked by steph
  156. Algebra 2

    My question involves "Graphic Representation of Radicals of the Second Order" I know that the length of the hypotneuse of a right triangle equals the square root of the sum of the lengths of the two legs. The problems I'm having trouble with are the square

    asked by Josh S
  157. Math

    john earns $10 per hour and made a total $825. How many hours did he work during this period? Write an equation to represent this situation.

    asked by Brianna
  158. BA

    use scientific notation to divide the two numbers, express answer using scientific notation, retain at least 3 decimal place for (8.4.10^6)/(5.97.10^2)

    asked by Dechols
  159. Physics

    The boiling point of helium at 1 atm is 4.2 K. What is the volume occupied by helium gas due to evaporation of 70 g of liquid helium at 1 atm pressure and a temperature of 6.2 K?

    asked by Gabe
  160. math

    what is 9+9d=8d-12

    asked by taylor
  161. Probability

    Suppose that an unfair coin comes up heads 54.1% of the time. The coin is flipped a total of 13 times. a) What is the probability that you get exactly 6 heads? b) What is the probability that you get exactly 6 tails? c) What is the probability that you get

    asked by Vikki
  162. Biology

    Some questions fall outside of the realm of science;which of the following questions could not be ansewered usingf the scientifec method

    asked by Anonymous
  163. physics

    A car starting from rest accelerates uniformly are attaing a speed of 80m/s in 30s it maintains this stedy speed for another 30s. It then slow down uniformly until it comes to rest in the next 40s

    asked by adeyemi
  164. chemistry

    weight of watch glass+funnel= 121.573g weight of watch glass+funnel+CaC2O4H2O=122.044 g how many moles of CaC2O4H2O were isolated during the experiment? related equations: HO2CCO2H + OH- -> -O2CCO2- + H2O Ca2+ + -O2CCO2- + H2O ->CaC2O4*H2O

    asked by anna
  165. physics

    A 2.80 kg steel ball strikes a massive wall at 12.8 m/s at an angle of alpha = 50.9° with the plane of the wall. It bounces off with the same speed and angle. If the ball is in contact with the wall for 0.156 s, what is the magnitude of the average force

    asked by Tom
  166. chemistry

    How many moles of sodium hydroxide are produced when 0.155 mole of sodium reacts with excess water?

    asked by Cris
  167. math

    lisa made a long-distance telephone call to her friend Jane. the cost was $.42 for the fist minute and $.19 for each additional minute. what was the total length of the call if it cost $2.89

    asked by NELLIE
  168. math

    The building is 16 by 12 feet so, to the nearest tenth of a foot what distance (x) fom the building should time place the 16-ft ladder so that the top of the ladder will be 12 feet above the ground?

    asked by Nicole
  169. math

    antonio wants to buy a car that costs $2,500. he plans to put $400 down and pay the rest in six equal payments. find the amount of each payment

    asked by PATRICE
  170. chemistryhelp

    what does the electrolyte in batteries do?

    asked by joe
  171. physics

    A 16.3 kg block is dragged over a rough, horizontal surface by a constant force of 157 N acting at an angle of 35 degree above the horizontal. Find the work done by the 157 N force.

    asked by Anonymous
  172. Chemistry

    A 300.0g sample of ice at -30.OC is mixed with 300.0G of water at 90C. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capazities of H2O(s) and H20(L) are 2.03 and 4.18 j/g*C respectivly, and the entahply

    asked by Keru
  173. physics

    A rubber ball of mass 19.5 g is dropped from a height of 1.85 m onto a floor. The velocity of the ball is reversed by the collision with the floor, and the ball rebounds to a height of 1.55 m. What impulse was applied to the ball during the collision?

    asked by Tyler
  174. physics

    A bowling ball weighing 43.0 N initially moves at a speed of 4.90 m/s. How long must a force of 51.0 N be applied to the ball to stop it?

    asked by John
  175. math

    . In the annual walkathon, Lee jogs for 5 3/4 miles more than he walks. If he travelled a total of 15 miles, how many miles did he walk?

    asked by shelby
  176. algebra 1

    (w^3-57w+43) / (w+8)

    asked by amanda
  177. physics

    A skater of mass 74.0 kg initially moves in a straight line at a speed of 4.60 m/s. The skater approaches a child of mass 45.0 kg, whom he lifts on his shoulders. Assuming there are no external horizontal forces, what is the skater's final velocity?

    asked by John
  178. Math

    This question is from my workbook (Pre-Calculus 11). Can someone please help me understand it? Suppose theta is an angle in standard position with terminal army in quadrant III and tan theta = 6/3. Determine the exact calues of the other two primary

    asked by David
  179. Math

    y=5x-2 6x+3y=15 Please help me solve this system of equation and show your work thanks

    asked by Haylie

    1) Find the exact value. Use a sum or difference identity. tan (-15 degrees) 2) Rewrite the following expression as a trigonometric function of a single angle measure. cos 3x cos 4x - sin 3x sine 4x

    asked by cheyanne
  181. law

    • What is the role of police in society? What would happen if the role of the police were lessened as it applies to the theory and practice of community policing?

    asked by dan
  182. World History

    Around 700 B.C.,Athernians became unhappy with their form of government. What new type of government replaced it? A.aristocracy B.democracy C.oligarchy D.monarchy My answer is D ?

    asked by ciara
  183. Physics - Newtons laws

    A block (mass m1 = 8kg) is moving on an inclined plane, coefficient of kinetic friction of 0.45, whose angle is 30degrees. This block is connected to a second block (mass m2 = 22kg) by a cord that passes over a small frictionless pulley. Find the

    asked by Anonymous
  184. Physics

    What is energy

    asked by Vivek
  185. computer science

    my code works in c++ so the logical I am getting error must be in the reading of the problem, but I can't see it: Given a type Money that is a structured type with two int fields, dollars and cents. Assume that an array named monthlySales with 12 elements,

    asked by Cheryl
  186. algebra

    How much water should be added to 20oz of a 15% solution of alcohol to dilute it to s 10% alcohol solution?

    asked by rhonda