1. science/ chemistry

    Ethane (C2H6) is one of the many products of combustion of iso-octane, an important component of petrol. After release into the atmosphere, it is attacked by the hydroxyl radical, HO•, leading to its oxidation in the cycle of reactions when in a NOx-rich
  2. math

    Jerry mixes the letters F,P,M,M,M,F and j thoroughly.without looking. Amanda draws one letter expresses as a fraction, decimal, and percentage, what is the probability that j will not be the letter Amanda selects. 7/8 0.875, 87.5% <<<< 5/8
  3. Maths

    £2000 is invested at x% interest over three years. At the end of three years the money has grown to £2963. To the nearest percentage find the rate of interest. If you could help me out I would greatly appreciate it. I've tried to figure it out numerous
  4. Math Question

    Mr. hernandez had to interview a total of 63 households in his assignment. H has already finished 28. what percentage of the households in his assignments has he finished? (round your answer to the nearest tenth of a percent.) .... your aunt is building a
  5. math

    there are 2000 students in a course. thet wrote a mathematics test which was scored out of 40 and then converted to percentage. draw a flowchart that reads the name,sex and score of each student and output the name of the female students that scored below
  6. statistics

    The average middle-distance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. Find the percentage of a runners that will run the mile in less than 4 minutes?
  7. physics

    Unpolarized light is incident on four polarizing sheets with their transmission axes oriented as shown in the figure, in which θ1 = 27.0° and θ2 = 50.0°. What percentage of the initial light intensity is transmitted through this set of
  8. Chemistry

    I don't understand where to start first. Can you break it down for me? Ascorbic acid, also known as vitamin C, has a percentage composition of 40.9% C, 4.58% H, and 54.5% O. The molar mass of ascorbic acid is 176.1 g/mol. Determine the empirical and
  9. chemistry

    I have been at this question for at least three hours now. Consider the chemical system below. 2 NOCl(g) 2 NO(g) + Cl2(g) K = 1.6 10-5 What is the equilibrium concentration of nitrogen monoxide, [NO], given each of these initial conditions? (a) [NOCl]0 =
  10. chemistry

    Which would produce greater number of moles of product: a certain amount of hydrogen gas reacting with oxygen gas to make water, or the same amount of hydrogen gas reacting with nitrogen gas to make ammonia? Why?
  11. Physics

    During 2004, japanese scientists successfully tested two solar sails. One had somewhat complicated shape that we shall model as a disk 9 m in diameter and 7.5 um thick. The intensity of solar energy at this location was about 1400 W/m ^2. (a) What force
  12. Chemistry

    Automobile air bags employ a chemical reaction involving the rapid decomposition of sodium azide (NaN3) into sodium metal and nitrogen gas to inflate in a collision. How much sodium azide is required to decompose to inflate a 20.0 L air bag? Assume that
  13. chemistry

    10. If the calcium oxide were obtained by the heating of calcium hydroxide, how much hydroxide would be needed to obtain the 15.0 g? 11. If the 15.0 g of calcium oxide in the above problems were allowed to react with water, what amount of calcium hydroxide
  14. Honors Chemistry

    1. .0025 M tartaric acid completely reacts with .0030 M of Al bicarbonate if .913 l of CO2 forms at 298 Kelvin with pressure of 1.4 ATM how much base used? 2. 3.1 x 10^23 molecules of .0035 M hydriodic acid reacts with 25 grams of magnesium bicarbonate how
  15. Chemistry

    URGENT!!!!! 4 questions total! 1. .0025 M tartric acid completely reacts with .0030 m of al bicarbonate if .913 l of co2 forms at 298 k with pressure of 1.4 ATM how much base used? 2. 3.1 x 10^23 molec of .0035 m hydriodic acid reacts with 25 g of
  16. corporate finance

    1)You have just turned 30 years old, have just received your MBA, and have accepted your first job. Now you must decide how much money to put into your retirement plan. The plan works as follows: Every dollar in the plan earns 7% per year. You cannot make
  17. chemistry

    In which reaction does the smallest percentage change in volume occur? a) C3H8 (g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) b) 4NH3(g) + 3O2(g) ----> 2N2(g) + 6H2O(l) c) CH4(g)+ 2O2(g) ----> CO2(g) + 2H2O(l) d) 2H2S(g) + SO2 (g) ----> 3S(s) + 2H2O(l)
  18. statistics

    Heights of men on a baseball team have a bell-shaped distribution with a mean of 169 cm and a standard deviation of 9 cm. Using the empirical rule, what is the approximate percentage of the men between the following values? a. 151 cm and 187 cm. b. 160 cm
  19. chemistry

    In which reaction does the smallest percentage change in volume occur? a) C3H8 (g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) b) 4NH3(g) + 3O2(g) ----> 2N2(g) + 6H2O(l) c) CH4(g)+ 2O2(g) ----> CO2(g) + 2H2O(l) d) 2H2S(g) + SO2 (g) ----> 3S(s) + 2H2O(l)
  20. Intro to Ecology

    Global estimates of denitrification in terrestrial ecosystems vary widely but are of the order 200*102 g/yr, and more than half of that total occurs in wetland ecosystems. If restoration results in an increase in wetland area by approximately 25%, it would
  21. chem

    For the reaction: N2+3H2<--->2NH3 4.000 mol N2, 2.000 mol H2, and 6.000 mol NH3 are placed in a 2.000 L container and allowed to reach equilibrium. When equilibrium is established the [H2]=2.77 M. Calculate the equilibrium concentrations of nitrogen
  22. Chemistry

    A 0.0677g sample of magnesium metal reacted with excess hydrochloric acid to produce 69.9 ml of hydrogen gas. The gas was collected over water at 21.0 degrees Celsius. The levels of water inside and outside the gas collecting tube is identical. The water
  23. chemistry

    the molar mass of an unknown gas was measured by an effusion experiment. it took 63s for te gas to effuse. where as nitrogen gas took 48sec. what is the molar mass of the gas? 32g/mol 37g/mol 24g/mol 16g/mol 48g/mol
  24. finace

    15. Suppose that the following version of the APT is a good model of rick in the stock market. Consider three factors: the stock market’s excess return in percentage points, the change over the last year in the price of oil in dollars, and the spread
  25. Chemistry

    How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed
  26. chemistry

    How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed
  27. Chemistry

    How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed
  28. chemistry

    How can i calculate the concentration of each ions remaining in the solution after precipitation is complete? ok heres the full question:: 2KOH + Mg(NO3)2 -------------> 2KNO3 + Mg(OH)2 a 100.0 mL aliquot of 0.200 M aqueous potassium hydroxide is mixed
  29. Science

    Pineapple has high requirements for the fertilizer elements nitrogen (N), potassium (K), and iron (Fe), and relatively low requirements for the fertilizer elements phosphorus (P) and calcium (Ca). Although Hawaiian pineapples grow in red soils whose iron
  30. AP Chemistry

    Suppose the three gases were placed at 1.00 atm and 273 K in closed containers, as shown below. A tiny hole is opened in each container, allowing each gas to diffuse into another container filled with neon gas. What is the ratio of the rate of diffusion of
  31. O Chem

    In the laboratory process of isolating Eugenol from cloves via a steam distillation, extraction, drying, and final distillation what would be the best drying agent to use? Sodium Sulfate (Capacity=high Completeness=low rate=medium) or Magnesium
  32. Chemistry

    The reaction of nitrogen dioxide with fluorine generates nitryl fluoride: 2NO2(g) + F2(g) --> 2NO2F(g) To determine the rate law for this reaction, a chemist performed several initial-rate experiments using different initial concentration, with the
  33. Physics

    Many people mistakenly believe that the astronauts that orbit the Earth are "above gravity". Calculate g for space-shuttle territory, 206 kilometers above the Earth's surface. Earth's mass is 6e24 kg, and its radius is 6.38e6 m (6380 km). Your answer is
  34. physics

    A pitcher can throw a ball towards the home plate at 120km per hour. When thrown, the ball curves. The curveball has a spin of 1250rpm. The ball has a mass of 100g and a radius of 2.5cm Calculate the percentage of total KE that is in rotational KE
  35. chemistry

    3.0g of a mixture of potassium carbonate and potassium chloride were dissolved in a 250cm3 standard flask. 25cm3 of this solution required 40.00cm3 of 0.01M HCl for neutralization. What is the percentage by weight of K2CO3 in the mixture? (K = 39, O = 16,
  36. statistics

    8) Why did you choose this figure as the warranty? What percentage of bulbs would need to be replaced if you chose a warranty of 7000 or 7500? Justify your answer statistically. How do you explain this to the board of directors, marketing people and
  37. research in CriminalJustice

    The five year survival rate for Caucasians for all forms of cancer increased from 39% in the 1960's to 57% now. Express the change in two ways: (1) as an absolute difference in terms of percentage and (2) as a relative difference in terms of percent.
  38. Chemistry

    A 0.3146-g sample of a mixture of NaCl(s) and KBr(s) was dissolved in water. The resulting solution required 47.40 mL of 0.08765 M AgNO3(aq) to precipitate the Cl–(aq) and Br–(aq) as AgCl(s) and AgBr(s). Calculate the mass percentage of NaCl(s) in the
  39. science

    Identify one harmful activity that humans do that might change the percentage of water that is available as a resource? Predict the possible effects this activity could cause to the food chains in that area, the changes in the number and types of
  40. pharmacy calculation

    A suspension contains 2400 mg of active drug in 1000 ml waht is the percentage of drug in the final product? what is the answer? Total mass is 1000g + 2.400g. Percent by mass (m/m)= 2.4 /1002 * 100
  41. Math problem solving

    An octagonal stop sign can be cut from a square sheet of metal, 750mm on a side. To the nearest hundredth, what percentage of the metal square is wasted when the octagon is of maximum size ?
  42. chemistry

    Blue copper sulfate pentahydrate (CuSO4.5H2O) crystals were heated to give the white monohydrate. What percentage of water was lost? (molar mass of CuSO4.5H2O is 250.5 g/mol)
  43. chemistry

    6.0g of impure and hydrous Na2SO4 were made up to 1dm^3 of solution neutralize 22.20cm^3 of 0.1mol/dm^3 of HCL.calculate: a)concentration of Na2CO3 in mol/dm^3. b)concentration of Na2CO3 in gram/dm^3. c)percentage purity in carbon.
  44. chemistry

    6.0g of impure and hydrous Na2SO4 were made up to 1dm^3 of solution neutralize 22.20cm^3 of 0.1mol/dm^3 of HCL.calculate: a)concentration of Na2CO3 in mol/dm^3. b)concentration of Na2CO3 in gram/dm^3. c)percentage purity in carbon.
  45. chemistry(reacting masses)

    When a 1 g sample of limestone was dissolved in dilute hydrochloric acid completely,0.38 g of carbon dioxide was generated.What was the percentage by mass of calcium carbonate in limestone?(Relative atomic masses : C=12, O=16,Ca=40.1)
  46. physical

    Two identical half-open pipes each have a fundamental frequency of 450 Hz. What percentage change in the length of one of the pipes will cause a beat frequency of 13.0 Hz when they are sounded simultaneously? Assume the speed of sound in air is 342 m/s.
  47. Chemistry

    A 0.3146-g sample of a mixture of NaCl(s) and KBr(s) was dissolved in water. The resulting solution required 37.20 mL of 0.08765 M AgNO3(aq) to precipitate the Cl–(aq) and Br–(aq) as AgCl(s) and AgBr(s). Calculate the mass percentage of NaCl(s) in the
  48. Chemistry

    Nitrogen dioxide, a pollutant in the atmosphere, can combine with water to from nitric acid. One of the possible reactions is shown below. Calculate ∆G0 and Kp for this reaction at 25oC and comment of on the spontaneity of the reaction (MUST plot the
  49. Chemsitry

    Nitrogen dioxide, a pollutant in the atmosphere, can combine with water to from nitric acid. One of the possible reactions is shown below. Calculate ∆G0 and Kp for this reaction at 25oC and comment of on the spontaneity of the reaction (MUST plot the
  50. help! due tommorrow

    an assortment of coins contains 20 pennies, 2 nickels and 6 dimes what percentage of the coins are nickels? ( in the book the answer says 7% nickels) i want to know how to work out the problem
  51. Statistics

    Suppose that weights are bell shaped with a mean of 120 pounds and a standard deviation of 10 pounds. What percentage of weights is between 110 and 130 pounds
  52. math

    the price of a jacket was reduced by10%. during a special sale, the price was discounted another 10%. what was the total percentage discount from the original price of the jacket
  53. math help

    A roll of fabric is 12 yards long. A salesperson cuts three pieces off the roll measuring 2 3/4 yd, 5 1/3 yd, and 1 1/5 yd. Approximately what percentage of the roll of fabric remains? A 3% B 9% C 23% D 77%
  54. maths(percentage)

    A village lost 15% of it's cows in a flood and 10% of the remainder died of diseases. If no. Of cows were left now is 7650 what was the original no of cows before the flood ?
  55. History

    The percentage of African Americans unemployed during the Depression was twice the rest of the population. never accurately counted. less than the general population. five times the rest of the population.
  56. chemistry

    A 1L flask contains 0.2moles of air open to atmosphere at 0degree celcius. Upon heating some of the air is lost. What is the percentage of air remaining in the flask?
  57. statistics

    Women’s heights are normally distributed with a mean of 63.6 in and a sd of 2 .5in. The US Army requires women’s heights to be between 58 in and 80 in. Find the percentage of women meeting that height requirement.
  58. Chemistry

    A 0.327 g sample of a mixture of NaOH(s) and NaCl(s) requires 31.5 mL of 0.150 M HCl(aq) to react with all the NaOH(s). What is the mass percentage of the NaOH(s) in the mixture?
  59. Algebra

    a vendor sold 100 fresh chicken eggs. eight of them were sold at a profit of 30% while the rest were sold at a loss of 40%. what is the percentage gain or loss on the whole stock?
  60. biology

    21% of a population is homozygous dominant, 49% are heterozygous and 29% are homozygous recessive. if the Hardy-Weinberg Law applies, what percentage of the next generation is predicted to be homozygous recessive?
  61. chemistry

    40grams of sodium hydroxide was reacted with sulphuric acid to give 35grams sodium sulphate.calculate the percentage yield of sodium sulphate.
  62. Chemistry

    In this reaction: 2 HCl + Na2CO3 -> H2O + CO2 + 2 NaCl The HCl was diluted from 2M to 0.8M and I currently have 0.020 L of it. There is also Na2CO3. What would be four causes for a large error percentage? Is it possible that some of the HCl evaporated?
  63. Stat

    The lengths of pregnancies in a small rural village are Normally distributed with a mean of 268 days and a standard deviation of 12 days. What percentage of pregnancies last beyond 290 days?
  64. Math

    The diameters of bolts produced by a certain machine are normally distributed with a mean of 0.25 inches and a standard deviation of 0.01 inches. What percentage of bolts will have a diameter greater than 0.24 inches? A. 79.13% B. 82.46% C. 84.13% D.
  65. statistics

    Percentage grades in a large physics class follow a normal distribution with mean 58. It is known that 3% of students receive grades less than 39.2. What is the standard deviation of grades in the class?
  66. calculus

    The measurement of the radius of a circle is found to be 14 inches, with a possible error of 1/4 inch. Use differentials to approximate the possible error and the percentage error in computing the area of a circle.
  67. chemistry

    The glass panels of a sky roof need to be coated in order to screen out ultraviolet radiation (10-400 nm wavelength) but without color distortion in the visible spectrum. Candidate coating materials are gallium nitride (GaN) with a band gap,Eg, of 3.2 eV,
  68. PHYSICS

    What causes acid rain? Can you think of a way acid rain could be produced even without industrial pollution? [Hint: Plants produce carbon dioxide, Co2, which reacts with rainwater to produce bicarbonate ions, HCO 3-.] Give one reaction that produces acid
  69. Math

    I am not sure about this problem Find four large cities around the world and an approximate percentage rate of population growth for the countries in which the cities are located. Estimate the population in each of the four cities in 25 yr.
  70. chemistry

    a solution of an unknown metal chloride (0.8870 g) was treated with silver nitrate to yield (1.9132 g). calculate the percentage by mass of chloride in the unknown chloride
  71. Math

    the interest rate on car loans increase from 8% to 9%. Although this is a rise of only 1 percentage point, you will be paying ____% more in interest on your loan. If your interest payment was $400, what would it be with the increase?
  72. Math

    the interest rate on car loans increase from 8% to 9%. although this is a rise of only 1 percentage point, you will be paying ____% more in interest on you loan. If you interest payment was $400, what would it be with the increase?
  73. Maths

    A car depreciates in value by 15% for the first year and for each year later by 12% of its value at the beginning of that year. Calculate the percentage decrease in the value of the car after 3 years. Could someone please confirm the answer to be 38.048
  74. Math

    Suppose a cost-benefit model is given: y= 5x/105-x Where y is the cost in thousands of dollars of removing x percentage of a certain pollutant. Find the cost of removing each percent of pollutants: 0%, 45%
  75. Finance

    ABC corp. expects to receive $2000 per year for years and $3500 per year for the next 10 years. what is the percentage value of this 20 years cash flow? use an 7% discount rate
  76. chemistry

    a solution of an unknown metal chloride (0.8870 g) was treated with silver nitrate to yield (1.9132 g). calculate the percentage by mass of chloride in the unknown chloride
  77. biology

    Can change in heart rate due to exercise be expressed in percentage difference to compare the rest rate and the exercise rate? why is it a good/bad thing to do?
  78. Maths

    ABC corp. expects to receive $2000 per year for years and $3500 per year for the next 10 years. what is the percentage value of this 20 years cash flow? use an 7% discount rate
  79. BioChem

    Please help with this question. Insulin, antibodies, enzymes and progesterone are four of many molecules found in and around cells. Of these four__________ are/is not a protein. a. antibodies b. insulin and antibodies c. antibodies and progesterone d.
  80. MATH

    100 employees leave a business that originally included 2000 employees. What percentage of the original number of employees did NOT leave?
  81. percentage

    a student has an avg of 57%. he has 2 test left which was are both worth 5% and 1 assigment worth 1 %. he also has 1 one big asigment worth 5%. how much would he need minimun in all these to get a 80% avg by the end of it?
  82. Math

    The interest rate on an auto loan in May was 12 %. By September the rate was up to 14 %. How many percentage points did the interest rate increase over the period? How would I begin this?
  83. Maths Percentage

    Due to an increase in the price of sugar by 25%,by how much percent must a householder decrease the consumption of sugar so that there is no increase in the expenditure on sugar?
  84. computer

    You type in the value 56.4235 into the active cell. You then click Percentage Style Button. What will the cell show when completed? A 56.4235% B.56.4235% C.56.42% D.56%
  85. algebra

    Rita's tuition bill for last semester was $4360 If she paid $6052 in tuition this semester what was the percentage increase on her tuition Please help me as I am not sure of my answer which is 0.38%
  86. CHEMISTRY

    A 70g sample of iron ore(Fe2O3) was analyzed for Iron and found to contain 1700 Fe. Calculate the percentage of iron in the sample.
  87. Science

    A solution contains 60g of sugar in 480g of water calculate the concentration of solution in terms of mass by mass percentage of the solution
  88. Chemistry

    Calculating theoretical yield and percentage yield from preparation of 4-acetoxybenzoic acid from the interaction of 4-hydroxybenzoic acid and sulphuric acid
  89. math

    adnan bought 96 eggs at the rate of rs.40 per dozen and sold at the rate of rs.4 per eggs find the percentage of profit if 3 eggs were rotten
  90. Math

    During a contest, a radio station gave away 40 free tickets to a concert. Only 25 of the free tickets were used. What percent of the tickets was used? How do we figure out the percentage???
  91. Physics

    A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)
  92. Statistics

    Assuming that the heights of college women are normally distributed with mean 66 inches and standard deviation 2 inches, what percentage of women are shorter than 72 inches?
  93. Physics

    A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)
  94. math

    how much oxygen is required to convert total so2 into so3 tell me the percentage ratio of so2:o2 the reaction is so2+1/2o2=so3
  95. Physics

    A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)
  96. Maths

    A store marks up the price of a lounge by 80%. What percentage discount would bring the price of the lounge suite back to its original price?
  97. programming

    I am supposed to make a pseudocode for a fat gram calculator and I want to know if my code is correct. This is the instructions: Design a program that asks for the number of fat grams and calories in a food item. Validate the input as follows: - Make sure
  98. Is My Pseudocode Correct? - Programming

    I am supposed to make a pseudocode for a fat gram calculator. These are the instructions: Design a program that asks for the number of fat grams and calories in a food item. Validate the input as follows: - Make sure the number of fat grams and calories
  99. Stats -Math

    1. We are interested in conducting a study in order to determine what percentage of voters of a state would vote for the incumbent governor. What is the minimum size sample needed to estimate the population proportion with a margin of error of 0.05 or less
  100. nutrition

    Choose three nutritional labels off of food packaging. Explain the ingredients and how to read each label in terms of calories, protein, carbohydrates, fats, and percentage of daily recommended dietary value. Respond in a short essay format of 200 words of