Popular questions and responses by natalie
  1. chemistry

    Arrange the following aqueous solutions in order of decreasing freezing points (lowest to highest temperature): 0.10 m Na3PO4, 0.35 m NaCl, 0.20 m MgCl, 0.15 m C6H12O6 and 0.15 m CH3COOH.

    asked on July 20, 2015
  2. Chemistry

    (NH4)2S is a strong electrolyte. Determine the concentration of each of the individual ions in a 0.200 M (NH4)2S solution. [NH4] = M [S] = M

    asked on April 3, 2014
  3. chem

    A sample of oxygen gas was collected via water displacement. Since the oxygen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 26.4 °C is 725 torr, what is the partial pressure of

    asked on April 15, 2014
  4. English

    In the sentence "There comes a time when the cup of endurance runs over, and men are no longer willing to be plunged into an abyss of injustice," the bolded phrase creates a mood of __________ among the audience A.Panic B.Despair C.Anger D.Anticipation

    asked on December 2, 2015
  5. College Physics

    In a crash test, a 2000-kg van collides with a concrete support. The stopping time interval for the collision is 0.10 s, and the impulse exerted by the support on the van is 7.0×103N⋅s. A.) Determine the magnitude of the change in momentum. B.)Determine

    asked on October 2, 2018
  6. Physics

    a 0.30-m radius automobile tire rotates how many rad after starting from rest and accelerating at a constant 2.0 rad/s^2 over a 3.54-s interval

    asked on April 20, 2015
  7. Chemistry

    -Consider the reaction when aqueous solutions of silver(I) nitrate and manganese(II) chloride are combined. The net ionic equation for this reaction is? -Consider the reaction when aqueous solutions of cobalt(II) sulfate and lead(II) nitrate are combined.

    asked on March 5, 2018

    A and B run around a circular track whose cicumference is 150m. when they run is opposite directions they meet every 5 seconds, but when they run in the same direction from the some point they are together every 25 seconds. what are their rates? ans. 18m/s

    asked on June 20, 2015
  9. Chemistry

    Iodine 131 is a radioactive isotope. After 4.00 days, 70.8% of a sample of 131I remains.What is the half life of 131I?

    asked on April 26, 2014
  10. Calculus I

    Hello, The pressure P and volume V of an expanding gas are related by the formula PVb=C, where b and C are constants (this holds in adiabatic expansion, without heat gain or loss). Find dPdt if b=1.6, P=12kPa, V=80cm2, and dVdt=20cm3/min. Thus far, I got

    asked on April 10, 2015
  11. Math

    write an inequality to represent the situation: The temperature stayed above -15

    asked on April 2, 2018
  12. science

    Name the type of reaction that the equation represents? 2Cu + O2 -------> 2CuO

    asked on February 11, 2012
  13. Math

    Jamie spenta total of $11.60 on 5dentical pens and a ruler .A rulercost$1.30less than a pen .how much did a pen cost?

    asked on April 9, 2017
  14. Chemistry

    A mole of methane reacts with 64g of oxygen at 1 atm, 425 K. There are two ways in which methane can react with oxygen. It can either form water vapor and carbon dioxide or water vapor and carbon monoxide. After reaction the final gas density is 0.7282

    asked on November 18, 2010
  15. Chemistry

    If you need to prepare 250.0 mL of a pH 5.00 buffer that has a total buffer concentration of acetic acid + sodium acetate of 0.050M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with

    asked on November 11, 2013
  16. Chemistry

    Assume that the normal blood buffer contains 0.00080 M carbonic acid and 0.0085 M hydrogen carbonate, the pKa = 6.35 for carbonic acid and the volume of blood in the body is 7.00 L. The blood pH, due to disruption is now 7.20. What is the ratio of

    asked on November 11, 2013
  17. Calc

    A cup of coffee at 90 degrees celsius is put into a 30 degree celsius room when t =0 . The coffee's temperature, f (t ) , is changing at a rate given by f '(t )=-8(0 .8) t degrees celsius per minute, where t is in minutes. Estimate the coffee's temperature

    asked on July 21, 2014
  18. Physics

    Two blocks are connected by a string on a pulley. One block is on an incline, and the other is hanging. The smooth inclined surface makes an angle of 35 ∘ with the horizontal, and the block on the incline has a mass of 5.7 kg. The mass of the hanging

    asked on February 25, 2015
  19. Home Economics

    List 5 careers that are possible from 3 areas in Home Economics. Why don't you list the areas of Home Economics first, then match those areas up with careers. I can think of cooking, sewing, (by the way, most Home Ec departments now prefer to be called

    asked on September 8, 2006
  20. Chemistry

    A piece of copper metal is initially at 100 C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20 C. After stirring, the final temperature of both copper and water is 25 C Assuming no heat losses, and that the

    asked on November 16, 2012
  21. Chemistry

    Calculate the change in the enthalpy of the reaction. C4H4(g)+2H2(g)===>C4H8(g) Use the following: change in enthalpy of combustion for: C4H4=-2341 kJ mol-1 H2=-286 kJ mol-1 C4H8=-2755 kJ mol-1

    asked on October 25, 2009
  22. statistics

    Can someone help me with this questions. Find the variance for a given data. Rpund your answer to one more decimal place then the original data. Compute the variance. Jeanne is currently taking college zoology. The instructor often gives quizzes. On the

    asked on August 28, 2007
  23. Math

    A pizza shop charges $2.00 for a slice that is one-eighth of a pizza and $3.00 for a slice that is one-fourth of a pizza. One day the pizza shop makes 6 pizzas. How much more money will they make if they slice all the pizzas into eighths than if they slice

    asked on November 29, 2018
  24. Precalculus with Trigonometry

    Prove or disprove the following identity: (sin(10x))/(sin(x)+sin(9x)) = (cos(5x))/(cos4x))

    asked on April 4, 2013
  25. Chemistry

    Calculate the standard enthalpy of formation of CuO2, given that: 2Cu2O + O2 ==> 4 CuO (-288 kJ) Cu2O ==> Cu + CuO (11 kJ) PLEASE HELP!!!!

    asked on October 26, 2009
  26. College Physics

    You are on vacation in San Francisco and decide to take a cable car to see the city. A 6100-kg cable car goes 410 m up a hill inclined 16 ∘ above the horizontal. The system is the car and Earth. Determine the change in the total energy of the system when

    asked on October 15, 2018

    How did fighting in the civil war change the lives of Texas soldiers ? a) They came to support the cause of secession b) They traveled far from home to participate in bloody battles c) They earned enough money to buy cotton plantations and slaves d) They

    asked on December 6, 2017
  28. algebra 1

    does 4x+5y=0 represent a direct variation? if so, find the constant of variation. complete the steps to solve 4x+5y=0 for y.

    asked on February 18, 2016
  29. Physics

    A person pushes on a 62-kg refrigerator with a horizontal force of -256 N; the minus sign indicates that the force points in the −x direction. The coefficient of static friction is 0.61. (a) If the refrigerator does not move, what are the magnitude and

    asked on September 27, 2011
  30. English

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

    asked on September 1, 2007
  31. math please help!!

    The depth d of water in a tank oscillates sinusoidally once every 4 hours. If the smallest depth is 7.9 feet and the largest depth is 10.1 feet, find a possible formula for the depth in terms of time t in hours. (Let the water depth be at the average when

    asked on September 3, 2015
  32. math

    For tax purposes, you may have to report the value of your assets, such as cars or refrigerators. The value you report drops with time. "Straight-line depreciation" assumes that the value is a linear function of time. If a $1020 refrigerator depreciates

    asked on August 27, 2015
  33. Chemistry

    How many lone pairs are in a chlorite ion (CLO2)- ?

    asked on October 14, 2013
  34. science

    1.40g each of CO, H2O, and H2 are sealed in a 1.41−L vessel and brought to equilibrium at 600 K. CO(g)+H2O(g)⇌CO2(g)+H2(g)KC=23.2 How many grams of CO2 will be present in the equilibrium mixture?

    asked on March 10, 2015
  35. math! please help!

    For a boat to float in a tidal bay, the water must be at least 2.7 meters deep. The depth of the water around the boat, d(t), in meters, where t is measured in hours since midnight, is d(t) = 5 + 4.6 sin(0.5t). (a) What is the period of the tides in hours?

    asked on September 2, 2015
  36. physics

    As some molten metal splashes, one droplet flies off to the east with initial speed vi at angle θi above the horizontal, and another droplet flies off to the west with the same speed at the same angle above the horizontal, as inthe figure. In terms of vi

    asked on October 15, 2010
  37. Government

    Hello, I need this question explained. You don't have to give me the answer ,but I just need a break down order to know what direction i need to go in. I know what it means to be political..I guess Im just confused by the question. Please Help ! (

    asked on May 2, 2011
  38. phsical science

    a tire contains air ata pressure of 2.8 bar at 10 degree celsius.if the tires volume is unchanged what will the air pressure in it be when the tire warms up to 35 degree celsius if the car is driven.

    asked on June 20, 2012
  39. Math--Area

    Find the area of each regular polygon to the nearest tenth. Octagon with side length of 10 kilometers. Heres what I tried; but I don't know if im on the right track. Area=1/2 * Perimeter* Apothem Perimeter=base of octagon* number of sides Perimeter=10*8=80

    asked on April 4, 2007
  40. Physics

    Consider the equation v = 1/8zxt2. The dimensions of the variables v, x, and t are [L]/[T], [L], and [T], respectively. The numerical factor 8 is dimensionless. What must be the dimensions of the variable z, such that both sides of the equation have the

    asked on September 4, 2013
  41. BOB

    A sphere of radius 20 cm and mass 1.80 kg starts from rest and rolls without slipping down a 30.0 degree incline...

    asked on March 10, 2015
  42. Language Arts

    3 main points for a speech on the alphabet

    asked on September 30, 2013
  43. chemistry

    Knowing the concentration of a solution allows us to find all of the following except A. the mass of a solute. B. the mass of the solvent. C. the volume of the solvent. D. the concentration of a solution when conditions change.

    asked on March 19, 2014
  44. Math

    Fay's rubber ball bounces exactly half the height from which it is dropped. She drops the ball from the top of a building that is 64 meters tall. How high will the ball bounce on its eighth bounce. Could someone explain this? Thank you! Natalie 1/2 of 64=

    asked on August 16, 2006
  45. Chemistry

    A piece of copper metal is initially at 100 C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20 C. After stirring, the final temperature of both copper and water is 25 C Assuming no heat losses, and that the

    asked on November 16, 2012
  46. chemistry 12

    sry, a misprint. its: O2+2F2 2OF2 The question is looking for Kc. 2.50 mo of oxygen and 2.50 mol of fluorine gas are placed in a 2.00L glass container at room temperature. The container is heated to 400K and the following equilbirum is established: O2+2F2

    asked on November 20, 2006
  47. World History

    Both Stalin in the Soviet Union and Hitler in Germany instituted ruthless campaigns against supposed enemies of the state. Why do you think dictators need to find scapegoats for their nation's ills?

    asked on March 17, 2010
  48. Biology

    What is the biological importance of what you observed? I observed different solutions pH levels (like water, skim milk, phosphate buffer, etc) before and after adding acid. I also observed different antacid solutions (alka-seltzer, tums, etc) to see how

    asked on September 3, 2019
  49. physics

    A car is traveling at 45.0 mi/h on a horizontal highway. (a) If the coefficient of static friction between road and tires on a rainy day is 0.100, what is the minimum distance in which the car will stop? ____ m (b) What is the stopping distance when the

    asked on November 1, 2010
  50. algebra 1

    a bout travels 280 miles downstream and back. The trip downstream took seven hours. The trip back took 14 hours. The speed of the boat in still water and the speed of the current

    asked on January 13, 2016
  51. math

    Triangle ADE is inside rectangle ABCD. Point E is half way between points B and C on the rectangle. Since AB is 8 cm and side AD is 7 cm. 1. what is the area of triangle ADE? 2. what is the ratio of the area of the triangle ABE to the area of triangle ADE?

    asked on April 14, 2013
  52. Calculus 2

    Find the area bounded by the curves y=sin(4x) and y=0 for x between x=0 and x=3pi/8.

    asked on January 29, 2018
  53. physics

    Heather in her Corvette accelerates at the rate of (3.40ihat- 2.00jhat) m/s2, while Jill in her Jaguar accelerates at (1.00ihat + 3.40jhat) m/s2. They both start from rest at the origin of an xy coordinate system. Determine the following after 5.50 s. (a)

    asked on October 19, 2010
  54. History

    In Uncle Tom's Cabin, (the book) did blacks have a racial caste system? Please explain

    asked on July 19, 2014
  55. Chemistry

    A piece of copper metal is initially at 100 C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20 C. After stirring, the final temperature of both copper and water is 25 C Assuming no heat losses, and that the

    asked on November 16, 2012
  56. Math

    a regular plot of land is designed so that its length is 6 meters more than its width. the diagonal of the land is 10 meters. to the nearest tenth of a meter, what are the dimensions of the land?

    asked on May 6, 2016
  57. accounting

    The balance in the unearned fees account before adjustment at the end of the year is 112,790. Of these fees, 69,735 have been earned. In addition, 13,200 of fees have been earned but have not been billed. Journalize the entry to the adjust the unearned

    asked on September 1, 2009
  58. Social Studies *Check Answers*

    Anyone mind checking these 2 quiz answers please? Which statement best explains why nation-states write constitutions? A: Constitutions give citizens unlimited powers. B: Constitutions establish nation-states. C: Constitutions allow governments to elect

    asked on December 11, 2016
  59. Math

    Marissa bought 2 1/4 gallons of orange juice to make punch. How many qts of oj did she buy? Marissa bought 6 fewer pints of soda than oj. How many cups of soda did she buy?

    asked on May 2, 2016
  60. Math

    A goblin miner earns 1 cent the first day, 2 cents the second day, 4 cents the third day, 8 cents the fourth day. How much will the miner earn in 30 days? Ok--I know to double the answer each time until 30--which would be:5,368,709.12 Is there an equation

    asked on August 21, 2006
  61. Chemistry

    A piece of copper metal is initially at 100 C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20 C. After stirring, the final temperature of both copper and water is 25 C Assuming no heat losses, and that the

    asked on November 16, 2012
  62. Math

    I have 25 ones and 3 tens.

    asked on July 22, 2019
  63. Chemistry

    1) A compound has the following percentages by mass: barium, 58.84%; sulfur, 13.74%; oxygen, 27.43%. Determine the empirical formula of the compound. 2) If a 1.271-g sample of aluminum metal is heated on a chlorine gas atmosphere, the mass of aluminum

    asked on December 30, 2011
  64. math

    . A jacket costs $94.95. It is on sale for 30% off. Estimate the sale price.

    asked on May 17, 2015
  65. English

    Which adjectives to describe an intense feeling about something

    asked on January 9, 2020
  66. chemistry

    What is the original molarity of an aqueous solution of ammonia (NH3) whose pH is 11.10 at 25 degrees C? (Kb for NH3=1.8 x 10^-5)

    asked on December 8, 2010

    A hypothetical planet has a mass 1.55 times that of Earth, but the same radius. What is g near its surface?

    asked on February 20, 2015
  68. Physics

    As two trains move along a track, their conductors suddenly notice that they are headed toward each other. The figure below gives their velocities v as functions of time t as the conductors slow the trains. The slowing processes begin when the trains are

    asked on September 7, 2011
  69. statistics

    If an instrument requires some professional judgments in scoring, then the manual should also include information on a. Interrater RELIABILITY b. Corrections of the reliability coefficients using the Spearman-Brown formula c, Both KR 20s and KR 21s d. Test

    asked on April 21, 2014
  70. math

    a 20-ounce bag of popcorn costs $2.80. if the unit price stays the same, how much does a 35-ounce bag of popcorn cost?

    asked on May 3, 2011
  71. math

    The desert temperature, H, oscillates daily between 36°F at 4 am and 56°F at 4 pm. Write a possible formula for H in terms of t, measured in hours from 4 am. I thought the answer is -10cos(1/6pi times t) +46 but it got marked wrong. I thought that the

    asked on September 2, 2015
  72. chemistry

    If 6.30 moles of C5H12 reacts with excess O2, how many moles of CO2 will be produced in the following combustion reaction?

    asked on October 15, 2015
  73. Brain Teaser

    What is the answer for this visual brain teaser? ii 00 00 00 00

    asked on March 19, 2008
  74. Math

    Jill and Matt run on a 400-meter-long oval track. They each run 10 laps daily and both run in the same lane. One day, they begin at the same point, but ran in opposite directions. Jill ran at a constant speed that was 2 meters per second faster than Matt's

    asked on October 22, 2008
  75. math

    A town has a population of 2000 people at time t = 0. In each of the following cases, write a formula for the population, P, of the town as a function of year t. (a) The population increases by 60 people per year. I thought it would be P= 2000 (1.03)^t (b)

    asked on August 28, 2015
  76. Calculus II

    Sketch the region enclosed by 2y=5x^(1/2), y=3, 2y+4x=9. Decide whether to integrate with respect to x or y, and then find the area of the region.

    asked on January 29, 2018
  77. Calc

    t 0 5 10 r(t)0 90 0 A shop is open 9 AM - 7 PM. The function r(t), gives the rate at which customers arrive (in people/hour) at time t, where t measures time in hours since 9 AM. Suppose that the salespeople can serve customers at a rate of 75 people per

    asked on July 21, 2014
  78. calculus

    Find a point c satisfying the conclusion of the Mean Value Theorem for the function f(x)= x^1/3 on the interval [1,8] I got f'(c)= 1/7 but am not sure where to go from there.

    asked on July 22, 2014
  79. Chemistry

    For the reaction, 2SO2(g) + O2(g) ¨ 2SO3(g) + heat, at equilibrium, what will be the effect on the net amount of SO3 present if the temperature of the container is increased? A) The concentration of SO3 decreases. B) The concentration of SO3 increases.

    asked on March 12, 2010
  80. college

    Please help me write a discussion on the 3 market shifts in the fashion industry

    asked on October 27, 2008
  81. science

    how physical/mechanical and chemical weathering different?

    asked on May 18, 2015
  82. Maths,geography nd science

    What are four factors that cause each of the social issues

    asked on August 14, 2017
  83. College Physics

    A person who is properly constrained by an over-the shoulder seat belt has a good chance of surviving a car collision if the deceleration does not exceed about 30 "g"s (1.0 g= 9.8m/s^2) Assumind uniform deceleration of this calue calculate the distance

    asked on July 2, 2012
  84. chemistry

    1) A Galvanic cell runs on the following reaction: Co (s) + Cu2+ (aq) → Co2+ (aq) + Cu (s) Draw a diagram for this Galvanic cell, labeling the electron flow, the anode and cathode, and the positive and negative sides of the Galvanic cell. 2) A Galvanic

    asked on January 25, 2017
  85. Chemistry

    You have a stock solution of 14.4 M NH3. how many mililiters of this solution should you dilute to make 1050mL of .220 M NH3 answer 16.o mL Question if you take a 10.5mL portion of the stock solution and dilute it to a total volume of .600L, what will be

    asked on February 21, 2011
  86. CHemistry

    Calculate the pH of a .25 M ammonium acetate (CH3COONH4) soluton. I thought u just did -log(.25) but it keeps saying that i have the wrong answer.

    asked on December 8, 2010
  87. Physics

    A 2.0kg object initially at rest explodes breaking into two pieces of mass 5.0kg and 15.0kg. If the 15.0kg piece moves with a speed 2m/s what is the speed of the 5.0kg piece? A. -6 m/s B. 15 m/s C. -5 m/s D. 20 m/s

    asked on April 6, 2015
  88. Chemistry

    how much heat is absorbed when 63.7 grams of water at 100 degrees Celsius is converted to steam at 100 degrees Celsius? -I need help figuring out how to do this.

    asked on March 4, 2015
  89. ochem

    when the concentration of CHBr3 and NaOH are both .145, the rate of the reaction is .0040 M/s. What is the rate of the eaction if the concentration of CHBr3 is doubled?if the conc. is halved?if the two conc. are both increased by a factor of five?

    asked on November 13, 2010
  90. social studies

    An early board game of ancient Egypt in which players moved their counters around the squares, please answer before 9:00 am (school starts) Luv Ya Bunches -Nat

    asked on April 12, 2010
  91. math please help me!

    Estimate the instantaneous rate of change of the function f(x) = x ln x at x = 1 and at x = 3. (Use h = 0.1, 0.01, 0.001, 0.0001, and so on. Round your answers to four decimal places.) f '(1) = f '(3) = What do these values suggest about the concavity of

    asked on September 16, 2015
  92. Calculus

    Find the derivative of y with respect to x. y= (lnx)/(3+4lnx) Should I start by using the quotient rule?

    asked on September 4, 2011
  93. Chemistry

    How do I find the molar enthalpy H (kJ/mol) for reaction of NH3 + HCl -> NH4Cl at temp 9.8 celsius by using Hess's Law. I do not understand why there are unknown variables and how to use that to find the molar enthalpy. PLEASE HELP. 1/2 N2 + 3/2 H2 + xH2o

    asked on November 4, 2017
  94. Math (functions)

    For tax purposes, you may have to report the value of your assets, such as cars or refrigerators. The value you report drops with time. "Straight-line depreciation" assumes that the value is a linear function of time. If a $1020 refrigerator depreciates

    asked on August 26, 2015
  95. Physics

    An Earth satellite moves in a circular orbit at a speed of 5800 m/s. a)What is the radius of the satellite's orbit? b) What is the period of the satellites orbit in hours?

    asked on October 23, 2012
  96. Physics

    From t = 0 to t = 5.00 min, a man stands still, and from t = 5.00 min to t = 10.0 min, he walks briskly in a straight line at a constant speed of 2.3 m/s. (a) What is his average velocity vavg in the interval 2.000 min to 7.90 min? I found this to be 1.15

    asked on September 5, 2011
  97. english

    why is sasha in trouble in the story "a problem"

    asked on October 10, 2014
  98. Physics

    A woman holds a 1.90-m-long uniform 5.0-kg pole as shown in (Figure 1) ( its horizontal). A. Determine the force she must exert on the pole at A. Express your answer to two significant figures and include the appropriate units. Enter positive value if the

    asked on December 11, 2015
  99. Accounting

    T/F Questions The main reason that the bank statement cash balance and the company's cash balance do not initially balance is due to timing differences. Sales Discounts is a revenue account with a credit balance. Multiple Choice: Assuming a 360-day year,

    asked on April 28, 2012
  100. physics

    What potential difference is required to reduce the initial speed of the proton by a factor of 2? A proton has an initial speed of 3.1×105 m/s .

    asked on February 3, 2016


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