tiffany

Most popular questions and responses by tiffany
  1. General Chemistry

    The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell =

    asked on April 14, 2014
  2. Math

    At the amusement park, you decide to ride the Ferris wheel, which has a maximum height of 50 meters and a diameter of 35 meters. It takes the wheel 5 minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates counter

    asked on June 19, 2015
  3. Chemistry

    Write and balance equation for the complete combustion of decane, C10H22

    asked on February 8, 2012
  4. Chemistry!!!

    Is the molarity of a solution that contains 6 moles of solute in 2 liters of solution 12 M????

    asked on May 1, 2010
  5. Chemistry (College) URGENT

    1.6g of an unknown monoprotic acid (HA) required 5.79 mL of a 0.35 M NaOH solution to reach the equivalence point. Determine the molar mass of the acid and given that the pH at the half way point to the equivalent point is 3.86. Calculate the Ka of the

    asked on October 29, 2012
  6. Chemistry

    if an excess of Al and 7.9 mol of Br2 are reacted in equation 2Al + 3Br2= 2AlBr2, how many moles of AlBr2 will be formed assuming a 100% yield

    asked on November 3, 2012
  7. physics

    A pitcher throws a 0.5kg ball of clay at a 6kg block of wood. The clay sticks to the wood on impact and their joint velocity afterwards is 3m/s. What is the original speed of the clay? I know the answer is 39m/s but I have no idea how they come up with

    asked on September 23, 2012
  8. calculus

    Which of the following are antiderivatives of f(x)=sinxcosx? I f(x)=(sin^2* x)/2 II f(x)=(cos^2* x)/2 III f(x)=-cos(2x)/4

    asked on March 11, 2012
  9. Chemistry

    The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell =

    asked on April 14, 2014
  10. chem 2

    calculate kc for reaction I2 (g)+Cl2 (g)⇌2ICl(g )Kp=81.9 (at 298 K)

    asked on October 6, 2013
  11. algebra 2

    what is the answer to algebra with pizzazz page 100; what should you say if you see a tall, wrought-iron tower in paris, france? there are 24 blanks

    asked on April 12, 2011
  12. ALGEBRA

    A transformer has cooling fans that are set to come on when the temperature reaches 32° Celsius. The temperature is 90° Fahrenheit. Are the fans running?

    asked on July 2, 2012
  13. Physics

    A cheetah can run approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey?

    asked on September 29, 2016
  14. Chemistry

    Silver chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride required to plate 195mg of pure silver.

    asked on July 7, 2010
  15. 2008 math

    Write the following as a sum using powers of 10 to show place value and explain your steps. 3) 620.83

    asked on July 10, 2012
  16. Chemistry

    A compound containing only C, H, and O was extracted from the bark of the sassafras tree. The combustion of 36.3mg produced 98.6 of CO2 and 20.2mg of H2O. The molar mass of the compound was 162 g/mol. Determine its empirical and molecular formulas

    asked on February 19, 2012
  17. Math

    Tommy has 5 jars. Each jar is 2/3 filled with marbles. How many full jars of marbles does tommy have ?

    asked on March 17, 2016
  18. statistics

    David wants to rent an unfurnished apartment for next semester. He took a random sample of 9 apartments adversised in the local Halifax paper, and recorded the rental rates. The rents (in $ per month) were: 500 650 600 505 450 550 515 495 640 a) Find a 90%

    asked on November 14, 2013
  19. Chemistry

    If 0.150 moles of salicylic acid and execs acetic anhydride are used during a synthesis of aspirin, how many grams of aspirin will be obtained if the reaction gives a 38% yield?

    asked on April 28, 2012
  20. college algebra

    The​ half-life of​ carbon-14 is 5600 years. If a piece of charcoal made from the wood of a tree shows only 73​% of the​ carbon-14 expected in living​ matter, when did the tree​ die?

    asked on December 6, 2015
  21. Calculus

    Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. Enclosed by y = x^2 − 4x + 1 and y = −x^2 + 4x − 5

    asked on December 11, 2013
  22. Chemistry

    A mass of 0.4113 g of an unknown acid, HA, is titrated with NaOH. If the acid reacts with 28.10 mL of 0.1055 M NaOH, what is the molar mass of the acid?

    asked on April 28, 2012
  23. Chemistry

    Find the volume of 0.250M sulfuric acid necessary to react completely with 79.3g sodium hydroxide

    asked on November 28, 2015
  24. Physics

    Josh starts his sled at the top of a 3.0m high hill that has a constant slope of 25 degrees. After reaching the bottom, he slides across a horizontal patch of snow. The hill is frictionless but the coefficient of kinetic friction between his sled and the

    asked on June 16, 2014
  25. physics!

    A 1.60-kg bottle of vintage wine is lying horizontally in a rack. The two surfaces on which the bottle rests are 90.0° apart, and the right surface makes an angle of 45.0° with respect to the horizontal. Each surface exerts a force on the bottle that is

    asked on February 7, 2011
  26. computers

    Wendy calls the help desk and reports that she is unable to access her files that are stored on the server. The network is a Windows Domain with Active Directory. Wendy is logged on locally to her workstation that runs Windows 8. You remote into her

    asked on December 23, 2014
  27. Urgent-Chemistry Help

    I need help with the heat effects and calorimetry worksheet. Please explain how to solve it! Thank you so much! A metal sample weighing 45.2g and at a temperature of 100.0 C was placed in 38.6g of water in a calorimeter at 25.6 C. At equilibrium the

    asked on December 4, 2006
  28. Writing

    Expository writing prompt: Describe a family celebration that has special meaning for you. Please give me some feedback. Every year my uncle celebrates Christmas at his house. Unlike the common Christmas party where people hand out presents to other

    asked on September 18, 2017
  29. Physics 202

    A rail gun uses electromagnetic forces to accelerate a projectile to very high velocities. The basic mechanism of acceleration is relatively simple and can be illustrated in the following example. A metal rod of mass 10.0g and electrical resistance 0.100Ω

    asked on February 17, 2015
  30. Chemistry

    A student placed 17.0 g of glucose (C_6H_{12}O_6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100 mL mark on the neck of the flask was reached. The flask was then shaken

    asked on July 7, 2010
  31. General Education

    Only circus animals with a clean bill of health will perform in today’s exhibition. A monkey, a poodle, and a horse will perform in today’s exhibition. No circus animals with a clean bill of health were prescribed medications this week. If the

    asked on July 20, 2014
  32. Math 75

    if you paid $120 to a loan company for the use of $2000 for 90 days, what annual rate of interest did they charge?

    asked on March 1, 2013
  33. math

    Noah wants to display his 72 collectors flags.he is going to put 6 flags in each row.how many rows of flags will he have in his display?

    asked on January 16, 2018
  34. Physics

    A record player rotates a record at 45 revolutions per minute. When the record player is switched off, it makes 5 complete turns at a constant angular acceleration before coming to rest. What was the magnitude of the angular acceleration (in rads/s2) of

    asked on June 20, 2017
  35. Chemistry

    To increase the solubility of a gas at constant temperature from 1.20 g/L at 1.4 atm to 2.3 g/L what would the pressure have to be increased to?

    asked on May 1, 2010
  36. General Education

    Aron: The two double A batteries in my CD player are dead, so the CD player doesn’t work. My television remote control, which also uses two double A batteries, works fine. So if I move the two batteries from my television remote control to my CD player,

    asked on July 20, 2014
  37. General Education

    Memmie: The greater the population near a restaurant, the more potential customers it has and the greater chance its popularity will spread through word-of-mouth. O’Sullivans Restaurant just opened in the very densely populated town of Redville, so its

    asked on July 20, 2014
  38. Beowulf question

    Why was it harder for Beowulf to kill Grendel's mother than Grendel himself?

    asked on July 1, 2009
  39. Chemistry

    NH4+ + OH- NH3 + H2O What is the K for the reaction above in terms of Ka's, Kb's, Kw etc.?

    asked on October 4, 2010
  40. Social Studies

    Why did the Pilgrims' government come about and why was its existence important. I know this has to do with the Mayflower Compact and was a formal method to establish systematic order among the Pilgrims but not sure why it came about and the importance.

    asked on September 8, 2016
  41. Physics

    The earth has about 80 times the mass of the earth’s moon. The gravitational force exerted on the moon by the earth has what relation to the gravitational force exerted on the earth by the moon? 1. the same as 2. zero; the earth exerts a force on the

    asked on January 18, 2015
  42. physics

    nucleus of oxygen-15 undergoes electron capture. Write out the reaction equation and determine the identity of the daughter nucleus

    asked on November 26, 2012
  43. smith

    The Smiths want to buy a 9 ft. by 12 ft. carpet and center it in a 15 ft. by 20 ft. room. What is the area of the carpet?

    asked on June 17, 2013
  44. Chemistry

    How many kilograms of chlorine are in 22 kg of each of the following chlorofluorocarbons CFCs? 1.CF2Cl2 2.CFCl3 3.C2F3Cl3 4.CF3Cl

    asked on July 7, 2010
  45. chemistry

    What volume of 16 M nitric acid must be diluted with distilled water to prepare 500.0 mL of 0.50 M HNO3?

    asked on August 2, 2009
  46. Physics

    Why are the tires for trucks carrying gasoline and other flammable fluids manufactured to be electrically conducting? 1. To make the truck easier to drive 2. To move the positive charges from the truck to the ground and avoid fire 3. To neutralize the

    asked on February 7, 2013
  47. calculus

    1. A conical reservoir has a depth of 24 feet and a circular top of radius 12 feet. It is being filled so that the depth of water is increasing at a constant rate of 4 feet per hour. Determine the rate in cubic feet per hour at which water is entering the

    asked on March 24, 2012
  48. chem

    Determination of the solubility product of PbI2. From the experimental data we obtain [I-] directly. To obtain Ksp for PbI2, we must calculate [Pb2+] in each equilibrium system. This is most easily done by constructing an equilibrium table. We first find

    asked on April 7, 2011
  49. Chemistry

    An antacid contains 200mg of aluminum hydroxide and 200mg of magnesium hydroxide per capsule. a. How many moles of Al(OH)3 does each capsule contain? 2.56 x 10^-3 mol Al(OH)3 is that correct? b. What is the mass in milligrams of 0.0457 mole of magnesium

    asked on July 1, 2013
  50. physics

    the frequency of middle C on a piano is 261.6hz. What is the wavelength of sound as it travels @room air and in water?

    asked on October 15, 2012
  51. Chemistry

    Give the formula of each of the following copper minerals: A. cuprite, copper (I) oxide B. chalcocite, copper (I) sulfide C. covellite, copper (II) sulfide

    asked on January 23, 2012
  52. Chemistry- Writing Net Ionic equations

    I need to write the net inonic equation for (NH4)2SO4(aq) and KNO2(aq). I need to know the reactants and the product. I worked it out and got: 2K+(aq) + SO4-(aq) ----> K(SO4)2(s)

    asked on March 1, 2010
  53. Practical English

    What is the topic sentence in this paragraph? (1)A trip to the ocean can be a relaxing escape from the everyday pressure of life. (2)A sailboat glistening on the horizon provides a mental escape to faraway places. (3)the rhythm of the ocean beating against

    asked on January 16, 2009
  54. Chemistry II

    At a certain temperature, Kc = 33 for the reaction: H2(g) + I2(g) 2HI(g) Assume that the initial concentrations of both H2 and I2 are 6.00 x 10-3 mol/L. Find the concentration of each reactant and product at equilibrium.

    asked on February 22, 2011
  55. intro to computers

    You call the help desk to report a problem you are having on your computer. The technician asks you what operating system you are running. You know it is Windows 7 but you forget which version. How can you find out?

    asked on December 7, 2014
  56. Chemistry

    Fill in the missing information in the following table of four neutral atoms Symbol- 37Cl number of protons- 36 46 number of neutrons- 42 number of electrons- 33 mass number- 77 106

    asked on January 25, 2012
  57. Chemistry

    Calculate the enthalpy change in kJ when 21.6g of H2S is burned. 2H2S(g) + 3O2(g) --> 2SO2(g) + 2H20(g) Change in H=-1036kJ/mol

    asked on October 31, 2010
  58. Physics

    A person pushes on a 60-kg refrigerator with a horizontal force of -260 N; the minus sign indicates that the force points in the -x direction. The coefficient of static friction is 0.68. (a) If the refrigerator does not move, what are the magnitude and

    asked on February 2, 2011
  59. Grammar (will you check the rest please)

    FIND THE ADVERBS 1. Pedro enthusiastically supported Zach's bid for student council president. ENTHUSIASTICALLY 2. Spend your money wisely. WISELY 3. Marissa waited quietly for the play to begin. QUIETLY 4. Lightly underline the words you want to

    asked on April 12, 2010
  60. Physics

    Sound of a certain wavelength is coming from within a room and passing through a rectangular door (a "slit"). If the width of the doorway is twice the wavelength of the sound, what is the diffraction angle è of the sound leaving the doorway? Please show

    asked on February 17, 2015
  61. physics

    A ball is thrown straight downward from the surface of the moon. Is the maximum height it reaches less than, equal to, or greater than the maximum height reached by a ball thrown upwards on the earth with the same initial speed? Ignore air resistance in

    asked on September 23, 2012
  62. Grammar (will you check the rest please)

    FIND THE ADVERB AND THE WORD IT MODIFIES 1. Mac looked everywhere for his jacket but could not find it.EVERYWHERE MODIFIES LOOKED AND FIND MODIFIES COULD 2. Tom threw the ball fast and hard. FAST, HARD MODIFIES THREW 3. Soon it will be time to go to sleep.

    asked on April 12, 2010
  63. Chemistry

    how many grams of NaCN would you need to dossolve in enough water to make exactly 250.0mL of soultion with pH of 10.00?

    asked on February 22, 2010
  64. Chemistry

    The specific heat of solid copper is 0.385 J/g*C. What thermal energy change occurs when the temperature of a 40.10g sample of copper is cooled from 42.9C to 10.0C? Be sure to give you answer the proper sign. I know this is part of the answer which

    asked on February 27, 2012
  65. PHYSICS

    Two horizontal forces, F1 and F2, are acting on a box, but only F1 is shown in the drawing. F2 can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the surface. Suppose that = +6.2 N

    asked on February 2, 2011
  66. chemistry

    how to write this as a net ionic equation? Al(s)+ H2SO4(aq)

    asked on April 22, 2008
  67. statistics

    a machine has 0.04 probability of producing a defective item. If it produces 6 items find: a. probability none is defective b. at least one is defective c. all are defective

    asked on March 17, 2014
  68. economics

    Give two examples of price discrimination. In each case, explain why the monopolist chooses to follow this business strategy.

    asked on May 24, 2012
  69. chemistry

    Imagine that you have a 7.00 gas tank and a 3.50 gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 115 , to what pressure

    asked on July 7, 2010
  70. chemisty

    what is the final pH after 1 drop(.05ml) of 6M HCl is added to 1.0L of freshly prepared pure water that was originally at a pH of 7.0. Is there a signigicant pH change?

    asked on March 1, 2010
  71. Physics

    A plastic rod is rubbed against a wool shirt, thereby acquiring a charge of −4.9 µC. How many electrons are transferred from the wool shirt to the plastic rod? The elemental charge is 1.6 × 10^-19C.

    asked on February 7, 2013
  72. Physics!

    One of the new events in the 2002 Winter Olympics was the sport of skeleton (see the photo). Starting at the top of a steep, icy track, a rider jumps onto a sled (known as a skeleton) and proceeds - belly down and head first - to slide down the track. The

    asked on February 24, 2011
  73. Physics (76)

    the weight of the block on the table is 422 N and that of the hanging block is 185 N. Ignoring all frictional effects and assuming the pulley to be massless, find (a) the acceleration of the two blocks and (b) the tension in the cord.

    asked on February 7, 2011
  74. Social Studies

    South Africa gained its independence from Britain in 1910. Why did this not lead to freedom and equality in South Africa?

    asked on April 11, 2019
  75. Chemistry

    Calculate the total heat energy needed to convert 110g of ice at -10°C to steam at 110°C..?

    asked on February 25, 2014
  76. Physics

    The ends of a light string are tied to two hooks A and B in a ceiling which are 100 cm apart horizontally so that the length between hooks is 140 cm. A 650g mass is then attached by a second length of string to a point C on the first, 80 cm from A, and

    asked on November 8, 2012
  77. Chemistry

    Calculate the mass of Fe(OH)3 s) produced by mixing 50.0 mL of 0.153 M KOH (aq) and 25.0 mL of 0.255 M Fe(NO3)3 (aq), and the number of moles of the excess reactant remaining in solution. I got 0.00383 mol Fe(NO3)3 remaining. I don't know how to obtain the

    asked on October 29, 2015
  78. Physics

    How much energy is required to change a 58 g ice cube from ice at −1◦C to steam at 101◦C? The specific heat of ice is 2090 J/kg ·◦ C and of water 4186 J/kg ·◦ C. The latent heat of fusion of water is 3.33 × 105 J/kg, its latent heat of

    asked on January 30, 2013
  79. Chemistry

    Calculate the solubility of LaF3 in grams per liter in the following solutions. The Ksp of LaF3 is 2.01 e-19. (a) pure water (b) 0.051 M KF solution (c) 0.065 M LaCl3 solution

    asked on October 1, 2010
  80. physics! please help

    A long distance swimmer is able to swim through still water at 4km/hr. She wishes to swim from Port Angeles, WA due north to Victoria, B.C., a distance of 50km. An ocean current flows through the Strait of Juan de !@#$%^&a from west to east at 3km/hr. In

    asked on October 19, 2008
  81. economics

    You are hired as the consultant to a monopolistically competitive firm. The firm reports the following information about its price, marginal cost, and average total cost. Can the firm possibly be maximizing profit? If not, what should it do to increase

    asked on May 24, 2012
  82. Physics

    A 123 g cube of ice at 0◦C is dropped into 1.9 kg of water that was originally at 81◦C. What is the final temperature of the water after after the ice melts? The latent heat of fusion of water is 3.33 × 105 J/kg . Answer in units of ◦C

    asked on January 30, 2013
  83. PHYSICS!!

    Air rushing over the wings of high-performance race cars generates unwanted horizontal air resistance but also causes a vertical downforce, which helps cars hug the track more securely. The coefficient of static friction between the track and the tires of

    asked on February 7, 2011
  84. Chemistry

    For a particular isomer of C8H18, the following reaction produces 5104.1 kJ of heat per mole of C8H18(g) consumed, under standard conditions. (deltaH_rnx = -5104.1kJ) What is the standard enthalpy of formation of this isomer of C8H18(g)?

    asked on April 11, 2016
  85. Bus.Math

    John O'Sullivan has just completed his first year in business. His records show that he spent the following in advertising: Newspaper $725 Radio $525 Yellow Pages $700 Local flyers $425 What percent of John's advertising was spent on the Yellow Pages?

    asked on May 16, 2012
  86. Math

    On a Science exam Rita answered 36 questions correctly and receive a score of 100% her friend answered 27 questions correctly what score did read her friend receive

    asked on July 8, 2017
  87. Physics help!

    An extreme skier, starting from rest, coasts down a mountain that makes an angle of 26.7 ° with the horizontal. The coefficient of kinetic friction between her skis and the snow is 0.248. She coasts for a distance of 10.5 m before coming to the edge of a

    asked on February 24, 2011
  88. spanish

    In the following sentences, change the position of the reflexive pronouns so that sentences retain their meaning. Have the correct account punctuation and accentuation. 1. Ellos vienen a despedirse esta noche 2. Daniel se esta afeitando 3. Patricia va a

    asked on February 8, 2012
  89. english

    1. Which of the following statements about Saadi's sayings is not true? A) They offer practical advice. B) They use simple language. C) They were composed in a time of chaos. D) They were written for other mystics. 2.What is a rubáiyát? A) a Chinese poem

    asked on October 29, 2009
  90. Calculus

    Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. (Round your answer to three decimal places.) Between y = e^x and y = x

    asked on December 11, 2013
  91. chemistry

    Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600–3200 and 1600 cm–1? A) The compound has a molecular mass of 94. B) The

    asked on December 11, 2011
  92. MATH (PLease HELp)

    Sally has three times as many dimes as nickels and twice as many quarters as dimes.In all she has $5.55. How many coins of each type does she have? Let 2x=quarters 3x=dimes x=nickles

    asked on October 18, 2011
  93. Chemistry

    A scientist wants to make a solution of tribasic sodium phosphate, Na3PO4, for a laboratory experiment. How many grams of Na3PO4 will be needed to produce 750 mL of a solution that has a concentration of Na^+ ions of 1.3 M? Express your answer numerically

    asked on July 7, 2010
  94. chemistry

    If the solubility of a particular solute is 10 g/100 g H2O at 20 oC, which of the following would represent a supersaturated solution of that solute: a) 9 g/100 g H2O at 20 oC, or b) 11 g/100 g H2O at 20 oC.

    asked on May 1, 2010
  95. Math

    mr blackwell tracks sales of ski equipment each week for a month. complete the table to determine which week had the highest percent of ski equipment sales.

    asked on September 24, 2013
  96. Math

    I am really have a tough time trying to solve this problem. I think my first three steps are correct but I am not sure. Could someone please help me? I got lost somewhere on one of these steps. I thonk it was step 3, 4, 5. Thank you. The two numbers chosen

    asked on February 10, 2011
  97. Brief Calculus

    The demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. p = −0.01x2 − 0.3x

    asked on August 3, 2016
  98. Computers (internet)

    How would you know whether a particular article from Wikipedia is accurate?

    asked on November 5, 2013
  99. Chemistry

    The uranium used for nuclear fuel exists in nature in several minerals. Calculate how many moles of uranium are in 6.0 moles of the following: Carnotite; K2(UO2)2(VO4)2*3H2O Uranophane; CaU2Si2O11*7H2O Autunite; Ca (UO2)2(PO4)2*10H2O

    asked on April 23, 2012
  100. Chemistry

    The specific heat of solid copper is 0.385 J/g*C. What thermal energy change occurs when the temperature of a 40.10g sample of copper is cooled from 42.9C to 10.0C? Be sure to give you answer the proper sign. I know this is part of the answer which

    asked on February 27, 2012

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