ellen

Most popular questions and responses by ellen
  1. Chemistry

    Typically, when a person coughs, he or she first inhales about 2.50 L of air at 1.00atm and 25 degreesC. The epiglottis and the vocal cords then shut, trapping the air in the lungs, where it is warmed to 37 degrees C and compressed to a volume of about

    asked on October 10, 2010
  2. speech

    traditional african mariage is an advantage for men only,not women?

    asked on April 14, 2015
  3. Chemistry

    The formaldehyde content of a pesticide preparation was determined by weighing 0.3124g of the liquid sample into a flask containing 50.0mL of 0.0996M NaOH and 50mL of 3% H2O2. Upon heating, the following reaction took place: OH- + HCHO + H2O2 -> HCOO- +

    asked on March 28, 2012
  4. chemistry

    Consider the titration of 21.0 mL sample of 0.110 M HC2H3O2 with 0.130 M NaOH. what is the initial pH? what is the volume of added base required to reach equivalance point? what is the pH at 5.00 mL of added base? pH at one half o the equivalence point? pH

    asked on July 29, 2010
  5. Physics

    A trapeze artist swings in simple harmonic motion with a period of 3.2 s. The acceleration of gravity is 9.81 m/s2 . Calculate the length of the cables supporting the trapeze. Answer in units of m.

    asked on March 4, 2011
  6. Physics

    A certain radioactive nucleus emits a gamma ray with an energy of 0.186 MeV. Calculate the mass lost by the nucleus during the decay process.

    asked on April 30, 2018
  7. math help

    Universal instruments found that the monthly demand for its new line of Galaxy Home Computers t months after placing the line on the market was given by D(t) = 2900 − 2300e−0.08t (t > 0) Graph this function and answer the following questions. (a) What

    asked on July 20, 2012
  8. Math

    What is the unit rate of drink 4/5 L in 1/4 hour

    asked on May 2, 2016
  9. Physics

    The respective charges on three identical metal spheres (q1, q2 and q3) are ̶ 16.9 µ C, 5.60 µ C and 2.6 µ C. The spheres are brought together so that they touch each other, and are then separated and placed on the x and y axes. Calculate the net

    asked on April 30, 2018
  10. Pre-Algebra please help me!!

    X- 0 1 2 3 4 5 6 Y- -7 -4 -1 2 5 8 11 this is a x and y table I need to find out wat the rule is to get y. So the equation would start out like: Y=?????? wat do u need to do with x to get y? and I need help badly! so please!

    asked on November 26, 2007
  11. Chemistry

    Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydrogen peroxide,H2O2, can be titrated against a solution of potassium permanganate, KMnO4. The following equation represents the

    asked on October 3, 2010
  12. Science

    1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it d? 2. A plant continues to grow throughout its life through the use of s a process called... a. alternation of generations

    asked on December 17, 2015
  13. 1 Science Question Unanswered

    Okay... I got all the answers. Thanks for the helps anyways. :( I just at least need one help. 1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it a or d?

    asked on December 17, 2015
  14. chemistry

    If 5.05mL of 0.1000 M NaOH solution is needed to just neutralize excess acid after 20.00 mL of HCl was added to 1.00 g of an antacid, how many moles of acid can the antacid counteract per gram?

    asked on July 27, 2010
  15. Chemistry

    The following reaction was monitored as a function of time: AB--->A+B A plot of 1/[AB] versus time yields a straight line with slope 5.2×10−2 . If the initial concentration of is 0.240M , and the reaction mixture initially contains no products, what are

    asked on July 18, 2010
  16. chemistry

    The Henry's law constant for CO2 at 20°C is 3.7*10^-2 M/atm. What mass of CO2 (in grams) is present in 355 mL of soda drink if the pressure of CO2 in the can is 2.5 atmospheres at 20°C? (Assume the solubility of CO2 in the soda is the same as water)

    asked on March 17, 2014
  17. Chemistry

    A 25.00mL sample of a household cleaning solution was diluted to 250.0mL in a volumetric flask. A 50.00mL aliquot of this solution required 40.38mL of 0.2506 M HCl to reach a bromocresol green end point. Calculate the weight/volume percentage of NH3 in the

    asked on March 28, 2012
  18. Chemistry

    80.0 mL of water is initially at room temperature (22degrees C). A chilled steel rod at 2 degrees C is placed in the water. If the final temperature of the system is 21.2 degrees C, what is the mass of the steel bar? Specific heat of water =

    asked on October 22, 2010
  19. Chemistry

    Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721mmHg?

    asked on October 10, 2010
  20. Chemistry

    We did a flame testing lab today with the following metal ions: Sodium, Na^+1 Barium, Ba ^2+ Calcium, Ca ^2+ Copper, Cu ^2+ Potassium, K ^+1 Strontium, Sr ^2+ Lithium, Li ^+1 The question asks to explain the effect of the nitrate ion solution on the color

    asked on December 16, 2008
  21. Physics

    Consider a pendulum of length 4.557 m. The acceleration of gravity is 9.832 m/s2 . a) What is its period at the North Pole? Answer in units of s. b) What is its frequency? Answer in units of Hz. c) What is its period in Chicago, where g = 9.803 m/s2?

    asked on March 4, 2011
  22. General Physics

    A 0.40 - kg object connected to light spring with a force constant of 19.6 N/m oscillates on a frictionless horizontal surface. If the spring is released from rest, determine the maximum speed of the object.

    asked on November 12, 2009
  23. chemistry

    need help with these problems: The concentration of glucose in blood is usually about 0.10% (w/v). If 7.0 L of blood are in an average man, how many grams of glucose are in his blood? To obtain the solute for 118 g of a 19.2% (w/w) solution of sugar we

    asked on July 20, 2010
  24. chemistry

    The following reaction was monitored as a function of time: AB--->A +B A plot of 1/[AB] versus time yields a straight line with slope 5.2 x 10^-2 M*s. What is the value of the rate constant (k) for this reaction at this temperature?

    asked on July 17, 2010
  25. Business

    whats is in their decision making process(How Gerber Used a Decision Tree in Strategic Decision-Making), can someone explain it to me because i don't get it. I'm going to need it for my assignment which is to Present and Give Observation on a Sample

    asked on December 12, 2016
  26. Pre Calc 12

    Four consecutive integers have a product of 360 Find the integers by writing a plynomial equation that represents the integers and then solving algebraically.

    asked on December 26, 2012
  27. Chemistry

    Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of Helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721 mmHg?

    asked on October 10, 2010
  28. chemistry

    how many molecules are present in 1.2 mol of glucose, C6H12O6?

    asked on December 12, 2012
  29. CH102

    If a temperature increase from 18.0 to 34.0 triples the rate constant for a reaction, what is the value of the activation barrier for the reaction?

    asked on July 16, 2010
  30. Science

    1. In plants, sexual reproduction occurs when sperm and egg unite to form a... a. gamete b. gametophyte c. sporophyte d. zygote Is it d? 2. A plant continues to grow throughout its life through the use of s a process called... a. alternation of generations

    asked on December 17, 2015
  31. Physics

    A hollow plastic spherical bobber of mass 0.005 kg and volume of 50 cm3 floats on the surface of a lake supporting a submersed fishhook and a bait with a combined mass of 0.01 kg and a combined volume of 2 cm3. The density of water is 0.001 kg/cm3. If a

    asked on March 24, 2010
  32. Pre-Algebra

    If negative 20 equals 168, negative 15 equals 153, negative 10 equals 138, negative 5 equals 123, 0 equals 108, 5 equals 93, 10 equals 78, 15 equals 63, 20 equals 48, then what is the rule??? Also, what is the pattern in the informatio above???

    asked on October 8, 2007
  33. chemistry

    How many grams of I2 are present in a solution if 33.75mL of 0.140M Na2S2O3 solution is needed to titrate the I2solution?

    asked on November 18, 2013
  34. Physics

    When light of wavelength 450 nm is passed through a certain diffraction grating, the first order diffraction maximum is found to be at an angle of 35° to the straight through. Calculate the distance between adjacent slits in the grating.

    asked on April 30, 2018
  35. physics

    A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .

    asked on October 12, 2011
  36. physics

    A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .

    asked on October 12, 2011
  37. math

    in a distribution of 160 values with a mean of 72,at least 120 fall within the interval 67-77. approximately what percentage of values should fall in the interval 62-82? use chebyshev's formula.

    asked on June 28, 2011
  38. physics

    The centers of a 6.0 lead ball and a 70 lead ball are separated by 8.0 . What gravitational force does each exert on the other? What is the ratio of this gravitational force to the weight of the 70 ball?

    asked on October 31, 2010
  39. English

    I need help with this question: replace the underlined nouns in this paragraph with personal pronouns.Write the pronouns on the lines below. The nouns have a number right next to them for you to read. Here is the paragraph: Squanto was a Pawtuxet Indian

    asked on September 28, 2007
  40. Calculus

    The following table shows the percentage of the U.S. Discretionary Budget allocated to education in 2003, 2005, and 2009 (t=0 represents 2000) Year t 3 5 9 Percentage p(t) 6.8 7 6.2 (a) Compute and interpret the average rate of change of P(t) (b) Over the

    asked on September 24, 2014
  41. math

    A t-shirt manufacturer uses 5/8 yard of material for each shirt, how many shirts can be made fro 14 & 38 yards of material?

    asked on October 5, 2013
  42. math

    The call letter of a radio station must have 4 letters.The first letter must be a K or a W. How many different station call letters can be made if repetitions are not allowed? *(If repetitions are allowed?)* *Important

    asked on June 3, 2012
  43. Chemistry

    Calculate the pH of a 0.10 M NaHX salt solution. Ka (H2X) = 2.1 x 10-2 Ka (HX-) = 4.5 x 10-8 Can someone explain the steps to do this please?

    asked on October 21, 2011
  44. physics

    A duck has a mass of 2.3 kg. As the duck paddles, a force of 0.07 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.26 N in a direction of 48° south of east. When these forces begin to act, the velocity of the

    asked on September 23, 2010
  45. Chemistry

    2Mg(s) + O2(g) 2MgO(s) If 9.92 g of Mg reacts with 8.52 g of O2. How many grams of MgO could be produced? I am just very confused and need an answer so that I can look back on how you got there . . .

    asked on January 12, 2015
  46. Chemistry - acids & bases

    4. Calculate the pH of each of the solutions and the change in pH to 0.01 pH units caused by adding 10.0 mL of 2.37-M HCl to 320. mL of each of the following solutions. Change is defined as final minus initial, so if the pH drops upon mixing the change is

    asked on October 24, 2016
  47. Physics

    A 1000Kg car is traveling at 40 m/s. a.) if the car stops in 20 seconds, what is the deceleration rate? b.) what friction force will stop the car in 20 seconds?

    asked on December 1, 2015
  48. chemistry

    Calculate the pH of the solution that results from the mixture. 170 mL of 0.12 M C2H5NH2 with 285.0 mL of 0.22 M C2H5NH3Cl.

    asked on July 28, 2010
  49. Biochem

    Using stocks of 0.1 M KH2PO4 and 0.1 M K2HPO4 how much 0.1 M K2HPO4 is needed to prepare 20 mL of a buffer solution at pH 7.2. The pKa of phosphate is 6.82. I know to solve for the ratio using henderson hasselbach but im lots after that! 5.2=6.82+log(A/HA)

    asked on September 19, 2016
  50. math 15

    find the minimum height above the surface of the earth so that the pilot at point a can see an object on the horizon at c 125 miles away. assume the diameter of the earth to be 8000 miles.

    asked on August 13, 2013
  51. Chemistry

    A volume of 50.0 mL of aqueous potassium hydroxide was titrated against a standard solution of sulfuric acid. What was the molarity of the KOH solution if 19.2 mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq) +H2SO4(aq)-» K2SO4(aq)+2H2O(l)

    asked on October 3, 2010
  52. Physics

    The hoover dam produces 2x10 to the 9 W of electricity. It is composed of 7x10 to the 9 kg of concrete. To produce 1 kg of concrete requires 1 MJ of energy. How much energy did it take to produce the dam? How long was the "energy payback time" for the dam?

    asked on February 2, 2011
  53. chemistry

    If 5.00 mL of HCl require 4.03 mL of 0.9581 M NaOH to just consume the HCl, what is the concentration of the HCl?

    asked on July 25, 2010
  54. economic - emergency

    Question concerning production function - Cobb douglas. Given is: y=(0,2K-1 + 0,8L-1)-1 If wk = wL =1, what will k and L be? Now suppose again: y=(0,2k-1 + 0,8L-1)-1 and z=K1/3*L2/3. Is product y or z always more demanding to capitals (in case of labour)?

    asked on September 27, 2006
  55. math

    Gail and 3 friends all share 1/2 a pie. All the pieces in pie put together make up 180 degrees. Gail and friends finish the pie and each eat an equal piece. They believe each piece has an angle of 25 degrees. Are they right?

    asked on January 7, 2014
  56. Macroeconomics

    If the government imposes a price ceiling of $100 on a market, what would happen in the market as a result of protests of price gauging by the sellers? What would happen to the price and quantity in the market?

    asked on May 12, 2013
  57. Inverse Functions

    Given that g is the inverse function of f, and f(3)=4, and f'(3)=5, then g'(4)= ?

    asked on June 5, 2012
  58. Physics

    A mass of 0.38 kg is attached to a spring and is set into vibration with a period of 0.22 s. What is the spring constant of the spring?

    asked on March 4, 2011
  59. math

    The ratio for red and blue skittles is 3:5. There are 20 more blue skittles. how many red skittles are there?

    asked on October 4, 2016
  60. physics

    a compound consist of carbon,hydrogen and oxygen only.the percentage by mass are carbon 40.0% and 6,7% hydrogen.calculate the empirical formulae

    asked on September 25, 2014
  61. math

    The call letter of a radio station must have 4 letters.The first letter must be a K or a W. How many different station call setters can be made if repetitions are not allowed? If repetitions are allowed? I have the answers just need to know the work

    asked on June 3, 2012
  62. Spanish-Check please! I need help

    Please check-I'm having a problem interpreting these questions and I have to answer them for homework. Could you please check my translation I'm not sure what these questions mean and I have to answer them for homework ¿Qué necesitas para comer en

    asked on March 21, 2012
  63. Physics

    Consider a frictionless track as shown in the figure below. A block of mass m1 = 5.75 kg is released from A. It makes a head on elastic collision at B with a block of mass m2 = 8.00 kg that is initially at rest. Calculate the maximum height to which m1

    asked on October 26, 2011
  64. science

    A segment of double-stranded DNA contains 31% Adenine (A) bases. a. What are the percentages of the other three bases in the DNA segment? (Count bases on both strands.) C: T: G:

    asked on September 28, 2011
  65. physical science 2

    the force required to maintain an object at a constant velocity in free space is equal to: b: the mass of the object. c: the force required to stop it. d zero

    asked on January 29, 2011
  66. physics

    A 4422.0 kg truck is parked on a 10.8° slope. What is the friction force on the truck?

    asked on October 9, 2008
  67. Social Studies: The Revolutionary War

    How did the fighting at Lexington and Concord affect the relationship between the colonies and the Great Britain?

    asked on October 7, 2007
  68. Math

    An apple pie uses 4 cups of apples and 3 cups of flour. An apple cobbler uses 2 cups of apples and 3 cups of flour. You have 16 cups of apples an 15 cups of flour. When you sell these at the Farmers market you make $3.00 profit per apple pie and $2.00

    asked on November 8, 2017
  69. Chemistry 30

    How do i do this question?? A 10.00ml Sample was taken from a 2Liter Container of Tropicana Orange juice. This sample was analyzed for its citric acid content by titration with a known 0.1112M NaOH base solution. A Phenoolphthalein indicator was added to

    asked on March 7, 2017
  70. Math

    Mark makes 10% of 100, Lindsay makes 5% of 400, Kelly makes 15% of 100, what's the median average?

    asked on August 10, 2016
  71. Chemistry

    Write the total and net ionic equations for the following molecular reaction: HgNO3 (aq) + NaCl (aq) -> HgCl (s) + 2 NaNO3 (aq)

    asked on February 20, 2014
  72. Pre Calculus

    mx3-nx2+5x-1 is divided by x-2 the remainder is -39. When divided by x-1 the remainder is 3. What are the values of m and n. Didn't know how to do the superscript for mx3

    asked on December 26, 2012
  73. physical science

    a car traveling in a lage circlepasses by a motorcycle that is trveling in a straight line north to south.both of their speedometers read 10m/s.which statement is true; a: the car and motorcycle have the same speed ,but different velocities,b:the car and

    asked on January 29, 2011
  74. chemistry

    what is the pH of 0.15 M NaF?

    asked on July 28, 2010
  75. chemistry

    need help setting this problem up: The heat of fusion of water is 335 J/g. How much heat would be required to melt 10.4 g of ice?

    asked on July 20, 2010
  76. finance and accounting

    Account Word Problems like this I seem not to get the concept , please give me an exam as how to figure out this problem. 1. The liabilities of Acosta Corporation equal one-third of the total assets. And stockholders equity is $160,000. What is the amount

    asked on March 4, 2008
  77. Pre-Algebra

    If negative 20 equals 168, negative 15 equals 153, negative 10 equals 138, negative 5 equals 123, 0 equals 108, 5 equals 93, 10 equals 78, 15 equals 63, 20 equals 48, then what is the rule??? Tables: X: -20 -15 -10 -5 0 5 10 15 20 Y: 168 153 138 123 108 93

    asked on October 8, 2007
  78. History

    Which of the following best describes a long-term political effect of the civil rights movement? A. The Democratic Party lost most of its support among white southern voters. B. African Americans came to dominate state legislatures across the South. C.

    asked on October 12, 2016
  79. physical science 2

    It takes 6 seconds for a stone dropped from rest to the bottom of a well,what is its final speed A; 6 meters/second B: 30 meters/seconds C: 36 meters/seconds D: 60 METERS/SECONDS A is incrrect

    asked on January 29, 2011
  80. Chemistry

    A calorimeter contains 21.0 mL of water at 14.0 degreesC. When 1.90 g of X (a substance with a molar mass of 70.0 g/mol) is added, it dissolves via the reaction X(s)+H_2O(l)reacts to make X(aq) and the temperature of the solution increases to 28.5degreesC.

    asked on October 22, 2010
  81. ch102

    The rate constant of a reaction at 30 was measured to be 5.7×10^-2. If the frequency factor is 1.2 x10^13 /s what is the activation barrier?

    asked on July 16, 2010
  82. math

    when y=-sinx and y=sin2x - sinx are added together and graphed, why do the maximum values of two sin functions occur where they do?

    asked on October 13, 2009
  83. Pre-Algebra

    So since 2/3 of Spinner 1 is sedans (The 3rd is a truck), and 1/2 of Spinner 2 is purple (the other half is a green), write a multipilcation problem to describe the probability of spinning a purple sedan. Write a problem to describe the probability of

    asked on November 8, 2007
  84. math

    The difference of two numbers is 9. The sum of 3 times the greater number and 4 more than the lesser number is 51. What are the two numbers? I do not get this question... I have tried many times, but can not get it.. please help! thank you.

    asked on September 20, 2007
  85. math

    perform the indication operation. express the answer in simplest forms

    asked on October 11, 2017
  86. Chemistry

    To completely react 17g of barium hydroxide, how many grams of hydrochloric acid is needed?

    asked on April 19, 2016
  87. literature

    What are the major events in Act I of A Doll's House?

    asked on October 15, 2012
  88. Spanish-Help Please

    I'm not sure what these questions mean and I have to answer them for homework ¿Qué necesitas para comer en cereal?does this ask what I need to eat cereal-like a spoon , bowl etc? 2. ¿Qué ríes mucho cuándo miras a los payasos?Do you laugh alot when

    asked on March 21, 2012
  89. Physics

    Two objects attract each other gravitationally with a force of 2.9 10-10 N when they are 0.29 m apart. Their total mass is 4.0 kg. Find their individual masses.

    asked on October 2, 2011
  90. chemersty

    Calculate the value of the following in exponential form, using standard scientific or "e" notation (for example, 105 = 1.05e2). Enter your answer with the correct number of significant figures. 885.75 g + 10.151 g - 25.50 g

    asked on September 10, 2011
  91. Maths

    Stuck! Help! 2.5 cubed? Xxxxx

    asked on August 22, 2011
  92. physical science 2

    A block is dragged at constant velocity in a straight line path across a level surface by force of 6 N. What is the friction between the black and the surface? a: 6 N B: less than 6 N C: More than 6N d: ZERO

    asked on January 29, 2011
  93. Chemistry

    An air sample contains 0.038% CO2. If the total pressure is 764 mm Hg , what is the partial pressure of CO2?

    asked on April 16, 2010
  94. Algerba 1

    Rewrite each polynomial as the product of two binomials. 1. y^2 + 6y + 9 2. 25x^2 - 10x + 1 3. 36 - y^2 I don't understand how to do these problems, especially what the direction is telling me to do. Someone help me please?

    asked on January 16, 2009
  95. Physical Science

    If you poked 3 holes in a vertical line in a bottle filled with water, which hole will spurt water the furthest? Why? -thanks so much for your help!

    asked on March 17, 2008
  96. Pre-Algebra

    You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and

    asked on December 10, 2007
  97. Math

    An apple pie uses 4 cups of apples and 3 cups of flour. An apple cobbler uses 2 cups of apples and 3 cups of flour. You have 16 cups of apples an 15 cups of flour. When you sell these at the Farmers market you make $3.00 profit per apple pie and $2.00

    asked on November 8, 2017
  98. english

    Hello! Is this good thesis? How can I make it better? I would recommend this novel to other readers because it is mysterious, appeals through emotions, but hard to understand some of the context. Thank you.

    asked on April 6, 2017
  99. maths fractions

    Marian had some pie. She ate ¼ of the pie. Now there is 1/3 left. How much pie did she originally have?

    asked on February 9, 2017
  100. Algebra

    Solve using set builder notation, show all work. 12x-25 is greater than or = to 3x-5(x+6)

    asked on July 28, 2012

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