Questions Asked on
April 20, 2014

  1. Chemistry

    Calculate ΔG° for the following reaction at 298 K.? A+B --> 2D ΔH° = 775.0 kJ ΔS°=296.0 J/K C --> D ΔH° = 446.0 kJ ΔS°=-218.0 J/K A+B --> 2C ΔG° = ? kJ I know I am suppose to reverse the (C --> D) and add a coefficient of 2 to both the enthalpy

    asked by Alexis
  2. chemistry

    Where possible, classify these systems as reactant-favored or product-favored at 298 K. If the direction cannot be determined from the information given, classify the reaction as "Insufficient information". a)2A(g) + 3B(g) -->4C(g) delta H = -95kJ b)2A(g)

    asked by Sophie
  3. physics

    When heat transfers into a system, is the energy stored as heat? Explain briefly.

    asked by Mohanad
  4. Chemistry

    If delta H°rxn and delta S°rxn are both positive values, what drives the spontaneous reaction and in what direction at standard conditions? The spontaneous reaction is a)enthalpy driven to the left. b)entropy driven to the right. c)entropy driven to the

    asked by Alexis
  5. Chemistry

    Predict how the entropy of the substance is affected in the following processes: a) O2 (g,200 kPa, 300k) --> O2 (g, 100, 300k) b)Br2 (l, 1 bar, 25 degree C) --> Br2 (g, 1 bar, 25 degree C) C)Fe (s, 1 bar, 250 degree C)--> Fe(s, 1 bar, 25 degree C) will

    asked by Alexis
  6. Maths

    The owner of a music store received a shipment of 1,532 cds the CDs came in 37 boxes the same number of cds were in 36 of the boxes how many cds were in the remaining box

    asked by Pinks
  7. Physics waves- check answers please

    1. If a bat emits 10 sounds in 5 seconds, what is the frequency of the bat's vocal outbursts (rounded to first decimal place) My answer: 2.0 Hz 2.If one crest has a 3 cm amplitude and interacts with another pulse to produce a crest 8 cm high this

    asked by Liz
  8. physics

    A 150-g block on the end of a spring with a spring constant of 35 N/m is pulled aside 25 cm and released from rest. In the electrical analog the maximum charge on the capacitor is 0.25 C.The maximum current in the LC circuit is

    asked by Anonymous
  9. Chemistry - check answer

    A 20.0 L reaction vessel contains 0.016 moles CO2, 1.05 moles of CO, and 2.00 moles of C. The mixture is approaching the following equilibrium: CO2(g) + C(s) 2CO(g) a) Calculate the reaction quotient Q. b) If value of K is 1.17, predict which direction the

    asked by Amanda
  10. chemistry

    If 2.33 L of propane (C3H8) at 24oC and 67.2 kPa is completely burned in excess oxygen, how many moles of carbon dioxide will be produced? a. Write a balanced equation for the reaction. b. Use stoichiometry to find the volume of carbon dioxide. c. Use the

    asked by Suzanne
  11. Statistics

    On an exam on probability concepts, Sue had an answer of 13/8 for one problem. Explain how she knew that this result was incorrect.

    asked by Traci
  12. Chemistry

    Given the equilibrium reaction N2(g) + 3 H2(g) 2NH3(g) + heat, an increase in temperature will: a) Increase the value of K b) Decrease the value of K c) Increase or decrease the value of K depending upon the concentration of reactants d) Will have no

    asked by Chloe
  13. chemistry Equations

    Write euations to show how a buffer made up of equimolar amounts of acetic acid, CH3COOH, and acetate, CH3COO-, would behave when (a) HCl was added and (b) NaOH was added. Is this right,If not what is the correct way? CH3COOH + HCl ----> CH3COOHCl + OH

    asked by Lan
  14. chemistry

    What are the products of the reaction between nitrous acid and strontium hydroxide?

    asked by Candy
  15. Chemistry

    Assuming that the specific heat of the solution is 4.18 J/(g⋅∘C) and that the calorimeter itself absorbs a negligible amount of heat, calculate ΔH in kilojoules for the reaction CaO(s)+H2O(l)→Ca(OH)2(aq) When 1.045 g of CaO is added to 50.0 mL of

    asked by Tyler
  16. statistics

    3coins are tossed calculate the followin probabilities p(3heads) p(2heads and 1 tail) p(3 tails)

    asked by shumaila.imtiaz
  17. statistics

    The Acme Candy Company claims that 60% of the jawbreakers it produces weigh more than .4ounces. Suppose that 800 jawbreakers are selected at random from the production lines. Would it be unusual for this sample of 800 to contain 494 jawbreakers that weigh

    asked by Anonymous
  18. Chemistry

    The equilibrium constant is 16 for the gas phase reaction SO2 + NO2 SO3 + NO at a certain temperature. If 3.0 moles each of SO2 and NO2 are placed together in an empty 1.0 liter flask and the system is allowed to come to equilibrium at this temperature,

    asked by Amanda
  19. Statistics

    Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the average tread life was 52,515 miles with a standard deviation of 3,550 miles. What is the best estimate of the average tread

    asked by Ray
  20. French

    travaille dans un magasin. ( rewrite the article and the noun) The salesclerk

    asked by ken
  21. statistics

    Fill in the blanks with the appropriate raw scores, z-scores, T-scores, and percentile ranks. NOTE: the Mean = 50, SD = 5. ________________________________________ Raw z T %ile ________________________________________ 35 1.2 35 16

    asked by Judi
  22. math

    A sum of money,X was deposited in a saving account at 10 percent compounded daily on 25 july 1993. on 13 august 1993, rm600 was withdrawn and the balance as on 31 december 1993 was RM 8900.calculate the value of X using exact time and 360 day year.

    asked by fizz
  23. math

    RM65000 will be invested for 6 years 9 months. if the investment will be offered 5% compounded semi annualy for the first 2 years, 6% compounded monthly for the next 18 months and 7% compounded daily for the rest of the period ,find the future value of

    asked by fizz
  24. Chemistry

    Calculate ΔH∘f (in kilojoules per mole) for benzene, C6H6, from the following data: 2C6H6(l)+15O2(g)→12CO2(g)+6H2O(l) ΔH∘ = -6534kJ ΔH∘f (CO2) = -393.5kJ/mol ΔH∘f (H2O) = - 285.8kJ/mol

    asked by Tyler
  25. Penn Foster

    Dramatic irony means that

    asked by Mary
  26. Physics

    A 60 man choir sings with the sound intensity of 70 dB in a 12m distance from the choir. a) What is the average sound intensity in this distance? b) What is the sound intensity in a 20 m distance ? Help please :)

    asked by Physics: Sound Intensity?
  27. Math

    Write an equation in slope intercept form of the line that is perpendicular to the given line and that passes through the given point 3x-4y=8 ; (-6,5)

    asked by Ava
  28. Statistics

    Recently, a university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was $25,577. The population standard deviation is $2,566. What is the 95% confidence

    asked by Ray
  29. statistics

    A sociologist is interested in the relation between x = numberof job changes and y = annual salary (in thousands of dollars) forpeople living in the Nashville area. A random sample of 10people employed in Nashville provided the followinginformation: x

    asked by John
  30. information literacy

    For an article to be considered scholarly, what element must it include? A: Detailed diagrams of the concepts presented B:criticism by academic peers C:a bibliography or a list or work sited D:a complete biography of the author or authors

    asked by amy
  31. Physics

    Table 1: Temperature and volume data Trial Temperature (Celsius) Volume (mL) Starting Volume Room Temperature = Hot Water Trial 1 106 5.2ml Hot Water Trial 2 107 5.4ml Cold Water Trial 1 lo 4.3ml Cold Water Trial 2 lo 4.3ml PLOT AREA (Insert a graph that

    asked by Char
  32. math

    what sum of money will become RM15000 in three year at a simple interest rate of 8% per annum?

    asked by fizz
  33. physics

    a bus decreases its speed from 80kmh-1to 60kmh-1 in 5 sec find the acceleration

    asked by motion
  34. math (check answer plz)

    all 500 students at robinson junior high were surveryed to find their favorite sport how many more students played football than basketball? Soccer: 10%, Football:38%, basketball: 27%, Baseball: 25%. . . . A.325 students B.135 students C.190***** D.55

    asked by person
  35. Chemistry

    If 2.5 g of NaOH is dissolved in 253 mL of water, what is the pH of the solution?

    asked by Lilly
  36. math

    1. Solve: 6C3 120***? 720 20 240 is this right?

    asked by TTR+S<3
  37. Macroeconomics

    A company is producing 100 units. At this quanity, it's average total cost is $25, and it's total fixed cost is $2,000. How much is it's total variable cost?

    asked by Russ
  38. Economics

    Please provide a definition of "Allocative Mechanism."

    asked by Chrstian
  39. math

    miss Thao owns a small hotel with 30 identical rooms. she finds that if she charges a price of 12 dollars ( or less) per room per day, all the rooms are rented. for every 1 dollar in price, 2 rooms remain vacant. each day, maintenance cost 4 dollars per

    asked by nhokaishiteru
  40. algebra

    perform the given operation. Let U = {1,2,3,4,5,6,7,8,9,10} enter the answer {1,2,8} U 2,8,9}

    asked by Mary
  41. calculus

    u have 7 different pass codes from a choice of 8 numbers how many possible outcomes are there

    asked by Anonymous
  42. L.O

    identify and introduce the human rights violation

    asked by coceka
  43. Bio/Chem

    If i change the concentration of the 3% hydrogen peroxide solution to 1.5%, am I changing its concentration or percent concentration?

    asked by Pink
  44. social studies

    How did the Fugitive Slave Act and the Kansas-Nebraska Act further divide the North and South? What role did the concept of popular sovereignty play in these conflicts? Do you think there was any way to avoid the violence that came out of this era? pls

    asked by TTR+S<3
  45. Probability

    Let U, V, and W be independent standard normal random variables (that is, independent normal random variables, each with mean 0 and variance 1), and let X=3U+4V and Y=U+W. Give a numerical answer for each part below. You may want to refer to the standard

    asked by A
  46. Probability

    Let X be a random variable that takes non-zero values in [1,∞), with a PDF of the form fX(x)=⎧⎩⎨cx3 if x≥1, 0,otherwise. Let U be a uniform random variable on [0,2]. Assume that X and U are independent. What is the value of the constant c? c=

    asked by A
  47. Probability

    Let N,X1,Y1,X2,Y2,… be independent random variables. The random variable N takes positive integer values and has mean a and variance r. The random variables Xi are independent and identically distributed with mean b and variance s, and the random

    asked by A
  48. Probability

    Manhole explosions (usually caused by gas leaks and sparks) are on the rise in your city. On any given day, the manhole cover near your house explodes with some unknown probability, which is the same across all days. We model this unknown probability of

    asked by A
  49. Probability

    Consider a fire alarm that senses the environment constantly to figure out if there is smoke in the air and hence to conclude whether there is a fire or not. Consider a simple model for this phenomenon. Let Θ be the unknown true state of the environment:

    asked by A
  50. Probability

    Let Θ be an unknown random variable that we wish to estimate. It has a prior distribution with mean 1 and variance 2. Let W be a noise term, another unknown random variable with mean 3 and variance 5. Assume that Θ and W are independent. We have two

    asked by A
  51. Statistics

    A survey of an urban university (population of 25,450) showed that 878 of 1,119 students sampled supported a fee increase to fund improvements to the student recreation center. Using the 95% level of confidence, what is the confidence interval for the

    asked by Ray
  52. Bio

    Scientific name for cow liver (used for a bio lab)

    asked by Pink
  53. Math

    Write an algebraic expression for "15 less than the product of the square of x and 5."

    asked by Bill
  54. math

    amy is 5 feet tall shes standing 12 feet from a street light if amy's shawdow is 4 feet long which porportion could be used to find the height of the street light

    asked by kay
  55. Math

    A model plane flies 18 ft per 2 seconds. What is the planes speed in miles per hour? Round to the nearest tenth.

    asked by Ava
  56. algebra

    Let U = {4,5,6,7,8,9,10}, A = {4,5,6,7}, B = {4,5,8,9} and C = {6,8,10}

    asked by Mary
  57. SS

    How does Iran spend its money?

    asked by Anonymous
  58. algebra

    How do you factor 2a^2+5x+3

    asked by Shane
  59. chemistry

    HCL acid is available as a stock solution with a concentration of 10 mol/L. If you need (2.100*10^0) L of (2.3*10^0) mol/L hydrochloric acid, approximately how much distilled water will you need to make the dilution?

    asked by Han
  60. Physics

    I've been working on this problem for close to an hour now and keep getting very wrong numbers... The two objects with different mass (m1 = 5.0 kg and m2 = 3.0 kg) in the Atwood's machine shown in the figure are released from rest, with one object at a

    asked by Confused
  61. Math

    For f(x)=3x+2. Find f(4)

    asked by Ava
  62. Ollu

    On a steamy mirror wipe away just enough to see your full face. How tall will the wiped are be compared with the vertical dimension of your face?

    asked by joe
  63. Algebra 1

    How do u graph inequalities?!?

    asked by Abbygail
  64. chemistry

    HCL acid is available as a stock solution with a concentration of 10 mol/L. If you need (9.0*10^-1) L of (2.50*10^0) mol/L hydrochloric acid, approximately how much distilled water will you need to make the dilution?

    asked by Han
  65. Math

    Explain a real-world problem that you used math to solve. What mathematical expressions did you use in your problem solving? Define your variables and explain your expression. My real-world situation would be making a cake and converting the cups into oz.

    asked by Stacy
  66. math (cant figure it out)

    Activity Boys Girls Total Walk 3 6 Bike 5 3 Skateboard 2 1 Total ______________ What percentage of the total students chose skateboarding? 10% 20% 30% none of these** . 4. What percentage of the boys chose walking? 30%* 45% 25% none of these . 5. What

    asked by person
  67. math/geometry

    Oil from a drum leaks into water surrounding the drum, creating a circular oil slick 100 square feet in area.Find the scale factor of the size transformation of the oil slick when it is 450 square feet in area. Round to the nearest hundredth.Where is the

    asked by breck
  68. Physics waves

    I am stuck with both of these questions. Thanks in advanced! 1. If one tone has a frequency of 110 Hz and another tone is played near it with a tone of 113 Hz, the beat frequency is ___ Hz 2. A standing wave has 3 nodes in a string 20 m long. The

    asked by Liz
  69. Maths

    Fred is 10 yrs older than Ted. In 3 yrs time Fred will be 3 times as old as Ted. Let Fred be x yrs old now. Write an equation to represent this situation. Solve equation and state how old each person is now.

    asked by David
  70. physics

    A square room has 3 mirrored walls of length L with one side missing. A laser is fired from the center of the open side of the room with an angle of incidence, I, toward the wall on the right. If the reflected beam is to hit a target on the back wall .80

    asked by ML
  71. physics

    Find the distance on a flat screen between the principal image and the second order bright fringe for red light(wavelength=664nm)if there are 900 slits per centimeter and the screen is 2.75 meters from the slits.

    asked by ML
  72. English, Reading

    i need help on a few questions from the book October sky/rocket boys so here they are: -name of the rockets (through chapters 1-8) and why did they name them that ? -what does sonny name his new launching site -who is valentine -why is the football team so

    asked by piper
  73. math

    3/4 of a gallon is 6/7 of the amount originally in the container. how much was in container originally

    asked by sierra
  74. English Help Please!!!

    Cohesion and Coherency/Sentence Variety This short paragraph has two distinct problems. First, to improve cohesion, rewrite these sentences so that old information is at the beginning of each sentence. Second, combine sentences and/or provide transitions

    asked by Kader
  75. us history

    Can you check if my answers are correct? When Jewish leaders proclaimed the independent state of Israel in 1948, the USA A. refused to recognize it until democratic elections were held B. broke diplomatic relations with most Arab states C. recognized the

    asked by Denisse
  76. US history

    Can you check if my answers are correct? Martin Luther King, Jr.’s eloquence hid the fact of his lack of formal education beyond the eighth grade. is it true? When black students tried to enter Little Rock’s Central High School in 1957, the governor

    asked by Denisse
  77. math

    find x when g(X)=0

    asked by james wilbert
  78. Math

    I studied for four hours. I added 2 more hours every day for a week. How many more days do I have to study until I have spend 20 hours studying?

    asked by Jeremiah
  79. Physical sciences

    The ruler now make contact with the neutral sphere.what happens to electrons?

    asked by Mbali
  80. SS

    What might happen in Cyprus in the future, politically and economically?

    asked by Anonymous
  81. COM 200

    All of the following are accurate tips for effective listening EXCEPT: (Points : 1) Listen to what the speaker doesn’t say as much as you listen to what is said. Paraphrase what you understand the speaker’s message is to help ensure understanding.

    asked by Anonymous
  82. statistics

    discuss the contribution of computer in the development of science and technology

    asked by shumaila.imtiaz
  83. statistics

    data shows number of absent student of statistic ciass. 3,5,7,4,6,0,1,4,3,2,8,5,4,7,1,5,2,6,7,8,3,9,1,0,5,6, form a frequency distribution by taking one class interval.

    asked by shumaila.imtiaz
  84. Math


    asked by Ellen
  85. Chemistry

    If the equilibrium constant for a reaction A + B C + D is K, which is true of the equilibrium constant K* for the reaction C + D A + B under the same conditions? A) K* = K B) K* = 1/K C) K* = 1 - K D) K* = 1 - (1/K) E) K* = 1 + K

    asked by Chloe
  86. math (SIMPLE INTEREST)

    4.the amount in an account which was opened 180 days ago is RM205. iF the account was offered a simple interest of 5 percent per annum, find the original principal. long does it take a sum of money to double itself in four years ?

    asked by fizz
  87. math

    8.Mary invested RM3000 in two accounts, some at 12% per annum and the rest at 8 percent per annum.Her total interest for one year was much was invested at each rate? 9.RM 1999 was invested for a certain period. The simple interest earned was

    asked by fizz
  88. math

    how many ways can 10 runners finish a race. 10 could finish 10 9 could finish 9 and so on would I times 10*9*8 ect that number seems way to big.

    asked by jill
  89. Math

    Mrs Chan has twice as many $5 notes as $10 notes and twice as many $10 notes as $50 notes. She has a total of $1080. How many $10 notes does she have?

    asked by Shannon Toh
  90. math

    4 red,5 blue,1 yellow marble Find the probability of picking a red marble then not replacing it and then drawing a blue marble. answer as a fraction,decimal and percent.

    asked by jill
  91. Maths, biology, accounting, business economics

    What career could one study with these subjects

    asked by Anonymous
  92. physics

    If a boulder of 9.7 tons is placed on a 70 degree incline, how much extra force would be needed to push the boulder up if the incline increases up by 5 degrees?

    asked by Nikki
  93. math

    Question 12.12. Katie had an unpaid balance of $1,734.50 on her credit card statement at the beginning of January. She made a payment of $165.00 during the month. If the interest rate on Katie's credit card was 7% per month on the unpaid balance, find the

    asked by Anonymous
  94. chemistry

    Calculate the enthalpy change, ÄH DeltaH, for the process in which 12.7g g of water is converted from liquid at 7.3 ∘ C \, ^\circ C to vapor at 25.0 ∘ C \, ^\circ C . For water, ÄH vap \Delta H_{\rm vap} = 44.0kJ/mol kJ/mol at 25.0 ∘ C \, ^\circ C

    asked by ntombiningi
  95. math

    Right triangle DEF has sides that measure x, x, and x squared for the some value of x. What is the area of triangle DEF to the nearest 0.1 square unit?

    asked by Melissa
  96. math (please check answer)

    Which of the following types of information is NOT suited for display on a scatter plot? 1. relationship between age and number of books read in a year*** 2. relationship between height and shoe size 3. relationship between calories consumed and body

    asked by person
  97. statistics


    asked by teri
  98. Chemistry

    In the. Reaction (Na2co3+CaCl2-->2NaCl+caco3) The precipitate is :

    asked by Mariam
  99. Chemistry

    In an experiment we have 4 liters of AlAin water in contain or A , and 2 liters of dubai water in contain out B . The alkalinity of water in container A and the alkalinity of water in container B are 50 and 150mg/l as caco3 ,,respectively the alkalinity of

    asked by Mariam
  100. Psychological and Psychophysiological Stress Disor

    What kind of traumatic events cause undiagnosable psychological disorders?

    asked by Ron
  101. Chemistry

    In TDS experiment , the mass of the empty beaker was 25.683g , and the mass of the beaker after water evaporated 25.687 g , if the volume of the sample 50 ml , then the TDS of the water sample is ?

    asked by Mariam
  102. Chemistry

    The separate suspended solid from a solution , we may use .......

    asked by Mariam
  103. Trig Maths

    solve the equation 5sin(θ -pi/6)=8cosθ for values of 0

    asked by bon
  104. Chemistry

    What are the Salts are taken into consideration in the calculation of the total alkalinity ????

    asked by Mariam
  105. Trig Maths

    solve the equation 5sin(θ -pi/6)=8cosθ for values of 0

    asked by bon
  106. Chemistry

    The measured experimental volume of ascetic acid in a sample of vinegar was 7% and the manufacture claimed volume is 5.8% , what is the percentage error ?

    asked by Mariam
  107. English

    1. I have seen her once. 2. I have once seen her. 3. I once have seen her. Which one is correct?

    asked by rfvv
  108. Chemistry

    A student mixed 40ml of 0.2m Na2co3 solution with 50 ml f 0.25M cacl2 solution , what is the except number of moles of naclkkw that I will be formed ?

    asked by Mariam
  109. Chemistry

    1.2g of NaCl as used to prepare 200 ml solution , what is the molar concentration of NaCl in solution ?

    asked by Mariam
  110. Chemistry

    If we put a drop of acid in a cup of natural water , the PH will ?

    asked by Mariam
  111. Chemistry

    The mass of watch glass is 24.5 g , the mass of watch glass plus white crystals befor drying is 29.1g , and the mass of watch glass and white crystals after drying 27.9 , thus the mass of the white crystals is !????!

    asked by Mariam
  112. Chemistry

    A water sample has TDS of 6000mg/l and the total hardness f 60mg/l , the water can be classified as ........

    asked by Mariam
  113. Chemistry

    What is the molarity of a NaOH solution if 21.3 mL of the NaOH solution is neutralized by 10.4 mL of 6.10 M H3PO4?

    asked by taytay
  114. Chemistry

    To remove temporary hardness we may use ?!!!

    asked by Mariam
  115. Chemistry

    What is the molarity of a solution of H3PO4 if 11.1 mL is neutralized by 33.2 mL of 0.161 M NaOH?

    asked by taytay
  116. Chemistry

    A student intend to prepare 200ml of 0.3M NaCl solution . The mass in gram of NaCl needed to prepare solution is ?!

    asked by Mariam
  117. Chemistry

    How many mL of 0.49 M HCl will neutralize 42 mL of 1.48 M NaOH?

    asked by Eric
  118. English Help Please!!! Check!!

    Concision Rewrite the sentences using concision techniques (replacing phrases with words, combining sentences, etc.) discussed in class to simply these wordy sentences. 1. Critics cannot avoid employing complex and abstract technical terms if they are to

    asked by Kimberly :(
  119. Dynamics

    A particle of mass m starts from rest and slides on a polished track around a vertical circular loop of radius a as shown. Show that the minimum starting height h above the bottom of the loop in order that the particle will leave the track at any point is

    asked by lexis
  120. chemistry urgent

    NH4NO3(s)+H2O(l)→NH4NO3(aq) ΔH = +25.7 kJ. What is the final temperature in a squeezed cold pack that contains 45.5g of NH4NO3 dissolved in 125 mL of water? Assume a specific heat of 4.18J/(g⋅∘C) for the solution, an initial temperature of 29.0∘C,

    asked by Tyler
  121. plz help !

    why is there something rather than nothing?

    asked by masaka cindy
  122. chemistry

    Lactic acid (CHgCHOHCOgH) is found in sour milk, in sauerkraut, and in muscles after activity. (K, for lactic acid I 1.4 X 1074.) (a) If 2.75 g of NaCH3CHOHCO2,

    asked by angela
  123. Social Studies

    Which of the following facts could be best used when supporting Kurdish independence? A. Most of the Kurdish people are not Shia Muslims, but are Sunni Muslims. B. Outside governments have repressed Kurds harshly before. C. Kurds were included in Iraq by

    asked by Anonymous
  124. Physics

    A man pulls a rope attached to a crate with a force of 120 N. If the rope makes an angle of 130 degrees with the ground, find the components of the force.

    asked by Gie
  125. Chemistry

    22mL of hydrogen was collected over wter at 19C and 745mmHg. What mass of magnesium is reacted (1:1 mole ratio)

    asked by Brett