1. CHEM HELP

    what is the theoretical mole ratio- NaCl to NaHCO3 How do you determine the percentage error of an experimental mole ratio It would be easier for us to help you if we had the entire problem instead of just parts of it. However, from the standpoint of Na,

    asked by CHEMISTRY HELP on January 2, 2007
  2. AP Chemistry

    Textrodotoxin is a toxic chemical found in fugu pufferish, a popular but rare delicacy in Japan. The compound has a LD50 (the amount of substance that is lethal to 50% of a population of iron (iii) hydroxide. Textrodotoxin is 41.38% carbon by mass, 13.16%

    asked by Rose23 on October 16, 2009
  3. Chemistry

    NaN3 is used in some automobile air bags. The impact of a collision triggers the decomposition of NaN3 as follows: 2NaN3(s) to 2Na(s) + 3N2(g). The nitrogen gas produced quickly inflates the air bag between the driver and the windshield. Calculate the

    asked by HaldriecH on August 6, 2010
  4. Chemistry

    Balanced Chemical Equation: 1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H20(g) If you start with: 5.0 x 10^4g hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yielded)? 2) How many moles of water can be produced? 3)

    asked by Roger on November 19, 2010
  5. Chemistry

    Balanced Chemical Equation: 1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H20(g) If you start with: 5.0 x 10^4g hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yielded)? 2) How many moles of water can be produced? 3)

    asked by Roger on November 19, 2010
  6. chemistry

    Gaseous hydrazine reacts with a gas X to form the gases nitrogen and HX by way of the following reaction: NH (g)+2X (g)=N (g)+4HX(g) The enthalpy change for Reaction 1 is −1180 kJ mol−1. Sketch or try and layout a fully labelled diagram showing how the

    asked by James Holland on January 25, 2011
  7. Math equation

    I've won 556 games and tied 4 games and lost 228 games what is my percentage of wins

    asked by Anonymous on December 11, 2016
  8. Chemistry

    What's the difference between relative and percentage abundance? What's the difference between realtive and average atomic mass? Is there a difference?

    asked by Taylor on August 20, 2013
  9. chemistry

    1. Nitrogen gas and sodium liquid are produced by the decomposition of sodium azide NaN3 (s). what volume of nitrogen gas, measured at 25 C and 0.980 atm, is produced by the decomposition of 62.5 g of sodium azide? 2. A gas sample in a container with a

    asked by Helen on December 10, 2010
  10. science

    during which phase is the least percentage of the light that hits the moon visible from earth? a) new moon b) waxing gibbous c) waning crescent d) full moon

    asked by victoria on October 30, 2013
  11. Maths

    A person stands in front of a cylindrical water tank and has a viewing angle of 27 degrees to the sides of the tank. What percentage of the circumference of the tank can they see?

    asked by Henry on March 15, 2018
  12. Chemistry

    9.3mL of ammonia base cleaner requires 12mL of 1M HCL to reach end point. A) what is molarity of ammonia and b) what is percentage of ammonia

    asked by John on September 20, 2017
  13. statistics

    the manager of a football team works for 310 days per year. of this he spends 42 days looking at new player he might buy. what percentage of his working days is this?

    asked by Anonymous on September 28, 2014
  14. Math

    2/5=what I assume you are looking for a decimal. Just divide 5 into 2, and the answer will be the decimal. However, if you are looking for a percentage, multiply the decimal by 100. I hope this helps. If not, repost with a clearer question. Thanks for

    asked by Amanda on April 12, 2007
  15. Chemistry

    Ammonia is often formed by reacting nitrogen and hydrogen gases. How many liters of ammonia gas can be formed from 17.2 L of hydrogen gas at 93.0°C and a pressure of 45.8 kPa??

    asked by tyrell on April 2, 2017
  16. chemistry

    Ammonia is often formed by reacting nitrogen and hydrogen gases. How many liters of ammonia gas can be formed from 23.7 L of hydrogen gas at 93.0°C and a pressure of 38.9 kPa?

    asked by anonymous on March 19, 2016
  17. Chemistry

    To clarify, a triple bond between carbon and oxygen is more stable than a triple bond between carbon and nitrogen because oxygen is more electronegative. Is my understanding correct?

    asked by Vivian on September 30, 2016
  18. ccbc

    A 12.3 vessel was found to contain N2, Ar He, and He. The total pressure in the vessel was 987 torr and the partial pressures of nitrogen, argon, and helium were 44 torr, 486 torr, and 218 torr, respectively. What was the pressure of neon in the vessel?

    asked by sam on October 14, 2013
  19. chemistry 116

    You have a rigid sealed container held at a constant temperature. You add 3.3 atm of oxygen gas, 1.7 atm of nitrogen and 4.2 atm of methane to it. What is the partial pressure of the oxygen gas in the container

    asked by ALEX GOLD on January 25, 2015
  20. Chem

    A 12.3 vessel was found to contain N2, Ar He, and He. The total pressure in the vessel was 987 torr and the partial pressures of nitrogen, argon, and helium were 44 torr, 486 torr, and 218 torr, respectively. What was the pressure of neon in the vessel?

    asked by Jose on November 11, 2010
  21. Are my answers correct? Chem

    I really need help with balancing these equations: Can you check if my answer are correct? Please 1. Sodium Hydrogen Sulfite reacts with hydrochloric acid to produce sulfur dioxide gas, water and sodium chloride NaHSO3 + HCl = SO2 + H2O + NaCl 2. Sodium

    asked by Anonymous on March 14, 2011
  22. chem 1p1

    An automobile tire at 22oC with an internal volume of 20.0L is filled with air to a total pressure of 30. psi(pounds per square inch). [1 atm = 14.696 lb/in2]. What is the amount in moles of air in the tire? If the air is mostly nitrogen, how many grams of

    asked by josh on April 23, 2010
  23. Ela

    All of the following sentences are complex EXCEPT A) Even though acid rain can have damaging effects, few people know much about it. B) Acid rain has been studied as an environmental issue by the government since the 1970s. C) Since they erode statues and

    asked by Superwoman on April 13, 2017
  24. Language Arts

    All of the following sentences are complex EXCEPT A) Even though acid rain can have damaging effects, few people know much about it. B) Acid rain has been studied as an environmental issue by the government since the 1970s. C) Since they erode statues and

    asked by Sally on April 14, 2017
  25. chemistry

    Triple Point Clicker Challenge The Lewis structure for nitroglycerin is shown below. 1.00 mL of liquid nitroglycerin is placed in a sealed, reinforced, insulated steel box measuring 1.00 m on each side and filled with argon gas at 15.0 oC and 1.00 atm. The

    asked by james on November 10, 2008
  26. 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)

    asked by mary on November 18, 2011
  27. chemistry

    A solution is made by dissolving 7.084 g of aluminum nitrate, Al(NO3)3, in 123.0 g of water. What is the mass percentage of solute in this solution? this feels like a simple problem but i just don't know. divide the two?

    asked by hershi on February 15, 2014
  28. Chemistry

    The average human body contains 5.30L of blood with a Fe2+ concentration of 2.30×10−5M . If a person ingests 11.0mL of 15.0mM NaCN , what percentage of iron(II) in the blood would be sequestered by the cyanide ion?

    asked by CHEMISTRY on March 15, 2009
  29. algebra

    400 Learners attended High School of the future for 4 days this past week. If 7 students were caught violating the uniform policy, what percentage was the overall compliance for the entire week???

    asked by Jasmn Theman on October 1, 2012
  30. six sigma

    If the mean value of the weight of a particular brand of dog food bag is 20.6 pounds and the standard deviation is 1.3, assume a normal distribution and calculate the percentage of bags that falls below the lower specification value of 19.7 pounds.

    asked by stansler on November 26, 2014
  31. chem

    help, i'd like to know how to do this titration question: for example: a 1g sample of naoh contaminated with na2co3 is titrated with 0.500MHCl, and it is found that 46.5mL of HCl are required for neutralization. Find the percentage by mass Na2Co3. thank

    asked by Alex on April 21, 2008
  32. Math

    the function 160x/100-x,models the cost,f(x), in millions of dollars,to remove x% of a river pollutants,if the government commits 240 million for this project, what percentage of pollutants can be removed?

    asked by Jasminee on November 9, 2015
  33. Quick Help (URGENT)

    1. What percentage of teen parents live in poverty? Is it 75 percent?? 2. How can you get HIV? Unprotected sex, anal, oral, vaginal. 3. What are the other methods of transmission of HIV? ??? Can someone check over my answers and help me with number 3?

    asked by John on October 5, 2009
  34. math

    obesity is defined as a body mass index of 30kg/m2 or more. A 95% confidence interval for the percentage of U.S. adults aged 20 years and over who were obesity was found to be 22.4 to 23.5%. What was the sample size???? Can you please show your work??

    asked by rina on October 6, 2011
  35. Sta

    A regular feature in a newspaper asks readers to respond via e-mail to a survey that requires a yes or no response. In the following day's newspaper, the percentage of yes and no responses are reported. discuss why we should ignore these statistics.

    asked by Rhea on September 19, 2010
  36. math

    The functionf(x) = 300x/100-x models the cost, F(x) in m illions of dollars to remove x% of a rivers pollutants. If the government commits $325 million for this project, what percentage of the pollutants can be removed?

    asked by willa on June 18, 2011
  37. general chemistry I

    Calculate the percentage error arising in an experiment if 1-mL, 5-mL, and 10-mL pipets are used for transfer and each pipet contains 5 drops of water adhering to the inside of the barrel. A single drop of water has an approximate volume of 0.05 mL.

    asked by Anonymous on September 18, 2014
  38. chemistry

    Calcium carbonate was reacted with hydrogen chloride. What is the percentage yield of carbon(iv)oxide produced if 3.65g of the gas is collected when 10g of calcium(iii)oxocarbonate reacts

    asked by tracia on January 12, 2016
  39. Jenish

    A 1200 W hair dryer is designed for 117 v. a) What will be the percentage change in power output if the voltage drops to 105 v. b) How would the actual change in resistivity with temperature affect your answer.

    asked by Physics on February 16, 2008
  40. Math

    A tire can hold C cubic feet of air. It loses a percentage of its air during each period of time, t. This rate of loss, written as a decimal, is r. This situation can be described using the following formula: C(1-r)^1. What effect, if any, does increasing

    asked by Patrick on August 30, 2018
  41. math

    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 the percentage of a runners that will run the mile in less than 4 min is %

    asked by angie on June 30, 2013
  42. science

    write word equations and balanced chemical equations for each of the following reactions: a)calcium bicarbonate reacts with hydrochloric acid. b)magnesium hydroxide reacts with hydrochloric acid. c)Aluminum hydroxide reacts with hydrochloric acid.

    asked by Adivhaho on June 22, 2016
  43. chemistry

    The gase in a mixture have the following partial pressures at the same volume and temperature, 1013000Pa nitrogen, 700mm argon, 1.20atm helium, 790 torr oxygen, and 0.50 atm of carbon dioxide. What is the total pressure of tyhe mixture in atm? You add

    asked by Chrissy on February 6, 2007
  44. AP Macroeconomics

    1. As an example of a price index, consider the A.C.D.P.I. (a fictitious price index). The associated basket of goods is: Good Quantity Price Coffee 3 lb $8/lb Bread 3 loaves $1/loaf Tea 1 lb $15/lb Aspirin 1 200-tablet bottle $2/bottle Cola 1 case $6/case

    asked by Emily on October 21, 2013
  45. Chemistry

    A compound contains only carbon, hydrogen, nitrogen, and oxygen. Combustion of 0.157 of the compound produced 0.213g CO2 and 0.0310 g H20. In another experiment, it is found that 0.103g of the compound produces 0.0230 g NH3. What is the empirical formula

    asked by Anonymous on April 15, 2010
  46. Chemistry

    bromine has two isotopes Br,79 and Br-81 the relative atomic mass of bromine is 79.9 calculate the percentage or br 79 atoms in a sample of bromine show all working out with all equations used and no abbreviations please

    asked by cake on November 14, 2017
  47. science

    Write down five atoms that you've interacted with today. It will depend on what you have done today. For me (and you will have your own set) Aluminium (in the drinks can) Potassium-40 (it was in the banana I had for breakfast) Carbon (in the plastic in

    asked by Lisa on March 28, 2007
  48. Chemistry

    Urea (NH2CONH2), an important nitrogen fertilizer, is produced industrially by the reaction 2NH3(g)+ CO2(g)--> NH2CONH2(aq)+ H2O(l). Given that delta G = -13.6 kj/mol, calculate delta G at 25 degree C.for the following condition. 40 atm NH3 , 40 atm CO2 ,

    asked by Anonymous on February 26, 2010
  49. Chemistry

    Nitrogen monoxide reacts with chlorine gas according to the reaction: 2NO (g) + Cl2 (g) ⇔ 2NOCl (g) Kp = 0.27 at 700 K A reaction mixture initially contains equal partial pressures of NO and Cl2 . At equilibrium, the partial pressure of NOCl is 115

    asked by Dave on April 4, 2017
  50. General Chemistry

    Answer Check Please... A compund contains only hydrogen and nitrogen and is 12.6% hydrogen by mass. A gaseous sample of the compound has desity of 0.925g/L at 690 torr and 110 degrees Celsius. What is the molecular formula of the compound? My Empirical

    asked by Kathy on September 5, 2011
  51. Chemistry

    Help required- Urea, CO(NH2)2, is the excreted form of excess nitrogen in most vertebrates. In urinary infections, urease, released by microbial pathogens, degrades urea into CO2 and ammonia in the bladder. a) write a balanced equation of the reaction, b)

    asked by AT on May 7, 2012
  52. Chemistry

    Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced? How many moles of NH3 are produced when 1.2moles H2 reacts?

    asked by Jennie on February 28, 2015
  53. physics please please please help me!

    A neutral nitrogen atom has 7 electrons, 7 protons, and 7 neutrons. What is its total charge? If we remove 2 of the electrons, now what is its charge? what is its charge if we add 2 electrons to the neutrol atom instead? give charge in Coloumbs.

    asked by Anonymous on January 20, 2013
  54. Chemistry - Solubility

    1.a) What did you observe upon the addition of NH3 (aq) to the magnesium chloride solution? Explain using relevant chemical reactions. I observed a colorless liquid. (Not sure how to explain) b) What happens when NH4Cl was added? Explain observation with

    asked by HelpThankYou on March 30, 2014
  55. Statistics

    To plan the budget for next year a college needs to estimate what impact current economic downturn might have on student requests for financial aid. Historically, this college has provided aid to 35% of its students. Officials look at a random sample of

    asked by Katie on November 11, 2013
  56. Finance

    Real and nominal rates interest   Zane Perelli currently has ​$120 that he can spend today on polo shirts costing $ 30 each. ​ Alternatively, he could invest the ​$120 in a​ risk-free U.S. Treasury security that is expected to earn

    asked by Asjhsd on April 26, 2018
  57. ANALYTICAL CHEMISTRY

    A 24-h urine specimen was diluted to 2.000L and buffered to pH 10.0. A 10.00 mL aliquot was titrated with 27.32 mL of 0.003960 M EDTA. The calcium in a second 10.00 mL aliquot was iso;ated as solid CaC2O4, redissolved and titrated with 12.21 mL of the EDTA

    asked by Anonymous on November 20, 2013
  58. chemistry

    Consider the reaction: N2(g) + 3 H2(g) --> 2 NH3(g). At a particular time, the nitrogen is being consumed at a rate of 0.60 moles/sec. At this same time, what is the rate at which ammonia is being formed? a. 3.0 mol/s b. 0.12 mol/s c. 0.30 mol/s d. 2.0

    asked by Jessie on January 11, 2017
  59. Marine Science

    I've searched and read so many things but i have yet to find the answer that my teacher is looking for. What percentage of energy is transferred from a producer to a: (A) secondary consumer, (B) tertiary consumer, (C) quaternary consumer?

    asked by Christin on March 8, 2010
  60. chemistry

    How will the relative number of moles of Mg and O be affected if the following procedural errors are made? Briefly explain (1) the crubile is not brought to constatn mass before the Mg is added. (2) water is not added after the first heating of Mg, and the

    asked by mariex3 on October 16, 2010
  61. Chemistry

    This Chem problem is really difficult -Need help please! Magnesium Consists of three naturally occuring isotopes. The percent abundance of these isotopes is as follows: 24Mg(78.70%), 25Mg(10.13%) and 26Mg(11.7%). The average atomic mass of the three

    asked by Mary Joy on September 27, 2012
  62. Chemistry Balancing Equations

    Can you please tell me if these are correct? 1. Sodium Hydrogen Sulfite reacts with hydrochloric acid to produce sulfur dioxide gas, water and sodium chloride NaHSO3 + HCl -----> SO2 + H2O + NaCl 2. Sodium nitrate reacts with hydrochloric acid to produce

    asked by Anonymous on March 14, 2011
  63. History

    Of the following,which occurred after the stock market crash in 1929? 1.The establishment of the Federal Deposit Insurance Corporation 2.The Wealth in the country owned by a small percentage of people 3.stocks being bough on the margin 4.use of credit to

    asked by Check Please on April 29, 2018
  64. Personal Dimensions of Education

    Which is the correct form of the verb provided to correctly complete the sentence. A high percentage of student population in the College of Health and Behavioral Sciences _____ planning to obtain an internship in the hospital while completing their

    asked by ACE on February 16, 2014
  65. Physics

    If a drummer at a gig hits his a drum that has a diameter of .2m with a stick that has a mass of 0.5kg at .03m from the center. What percentage radial region is impacted with a force twice as great as the initial impact force?

    asked by Sam on December 20, 2012
  66. math

    a pharmacist measures 60mL of glycerin by difference, starting with 100mL. After completing the measurement, he notes the graduate he used contained 45mL of glycerin. calculate the percentage of error incurred in the measure.

    asked by faye on September 3, 2014
  67. Chemistry

    Suppose there is a simulation of 25 helium molecules and 25 nitrogen molecules on the right hide of a box before the rate of effusion. Suppose you carry out this simulation and it does not give a precise quantitative reflection of Graham's Law. -->What

    asked by Anonymous on November 6, 2012
  68. Chemistry: Need Help

    Suppose there is a simulation of 25 helium molecules and 25 nitrogen molecules on the right side of a box before the rate of effusion. Suppose you carry out this simulation and it does not give a precise quantitative reflection of Graham's Law. -->What

    asked by Anonymous on November 6, 2012
  69. Chemistry

    a tank contains a mixture of 3.0 mol of nitrogen gas, 2.0 mol of oxygen gas and 1.0 of carbon dioxide gas at 25 degrees celsius and a total pressure of 10.0 atm. Calculate the partial pressure in torr of each gas in the mixture?

    asked by Elizabeth on July 11, 2011
  70. Chemistry

    Which one of the following compounds does not follow the octet rule? a) NF3 b) CF4 c) SF4 d) PH3 e) HCl I know I can eliminate A and B because nitrogen and carbon follow the octet rule. I know I can eliminate E because the total amount of valence electrons

    asked by Anon on April 27, 2017
  71. Math

    Use the normal distribution of weights of adult men, which has a mean of 170 pounds and a standard deviation of 7.5 pounds. Use the z-score chart to find the percentage of heights less than 155 pounds.

    asked by Edwin on November 17, 2016
  72. statistics

    a final exam in statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70?

    asked by erica on May 11, 2012
  73. chemistry

    1.00 tonne of ammonium from the harber process is reacted with carbon dioxide to prepare the fertiliser urea and 1.35 tonnes of urea are formed. calculate the percentage yield of urea

    asked by ellie smith on October 16, 2015
  74. geometry

    Please reference the illustration at screenshotsfirefoxcom/kzZjGCIcg9EMQ0MH/brilliantorg to answer the following question: What percentage of the square's area is colored blue? 30% 35% 40% 45% 50%

    asked by unowen on December 1, 2017
  75. staistics

    7) A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70?

    asked by Eli on November 19, 2016
  76. statistics

    7) A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70?

    asked by Anonymous on September 1, 2013
  77. chemistry(oxidation)

    ok,I really don't understand the whole oxidation numbers thing my question is state the oxidation number for nitrogen in the following NH3= -3 NO2-1= -1 N2= 0 NO2Cl= 5 N2H4 -2 am I correct? NH3= -3 NO2-1= -1 No, oxygen is -2, so N is +3 N2= 0 NO2Cl= 5 N2H4

    asked by mike on May 17, 2007
  78. Science

    A researcher wants to experiment with an element that reacts like phosphorus (P) but has a greater atomic mass. Which element should the researcher select for the experiment? A. Nitrogen (N) B. Sulfur (S) C. Arsenic (As) D. Silicon (Si) I choose Arsenic,

    asked by Baby_Banana on January 25, 2018
  79. chemistry

    A fuel mixture used in the early days of rocketry is composed of two liquids, hydrazine (N2H4) and dinitrogen tetraoxide (N2O4), which ignite on contact to form nitrogen gas and water vapor. 2 N2H4 + N2O4 --> 3 N2 + 6 H2O If 1.50 x 102 g of N2H4 and 2.00 x

    asked by Sheree' on November 5, 2012
  80. chem

    mass of mg- .28 mass of o- .41 calculate the moles of mg and o what is the simples whole number ratio of the moles of mg to the moles of o? round off to the nearest whole number ratio. use this mole ratio to write the empirical formula. the molecular mass

    asked by ashley on March 23, 2008
  81. Chemistry

    A 5.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure. What is the final pressure in the flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to -55°C?

    asked by Kanye on November 28, 2016
  82. Organic Chemistry lab

    So we did a preparation of t-pentyl Chloride experiment in class the other day using t-pentyl alcohol, HCL, Aqueous sodium Bicarbonate, and calcium chloride as the drying agent. Little confused on a few of these questions Why is calcium chloride used as

    asked by BigBlue on October 21, 2013
  83. Chemistry

    Magnesium metal reacts with HCl(aq) according to the equation: Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) In an experiment to determine the ΔH for this reaction, 0.158 g of Mg metal is combined with an excess of HCl to make 100.0 mL of solution in a coffee

    asked by Cali on December 4, 2016
  84. epidemiology

    The prevalence of previously undetected diabetes in a population to be screened is approximately 1.5% and it is assumed that 10,000 persons will be screened. The screening test will measure blood serum sugar content. A value of 180 mg percent or higher is

    asked by jessy on November 21, 2016
  85. IUPUI

    The prevalence of previously undetected diabetes in a population to be screened is approximately 1.5% and it is assumed that 10,000 persons will be screened. The screening test will measure blood serum sugar content. A value of 180 mg percent or higher is

    asked by jessy on November 21, 2016
  86. Science

    At a given temperature and pressure, the volume of a gaseous sample is directly proportional to the moles of gas (volume = C * moles, where C is a constant). Assuming that the tempreature and pressure is the same for the reaction of magnesium with HCl(aq)

    asked by Amy on March 14, 2013
  87. Science

    At a given temperature and pressure, the volume of a gaseous sample is directly proportional to the moles of gas (volume = C * moles, where C is a constant). Assuming that the tempreature and pressure is the same for the reaction of magnesium with HCl(aq)

    asked by Amy on March 14, 2013
  88. General Chem

    At a given temperature and pressure, the volume of a gaseous sample is directly proportional to the moles of gas (volume = C * moles, where C is a constant). Assuming that the tempreature and pressure is the same for the reaction of magnesium with HCl(aq)

    asked by Amy on March 11, 2013
  89. Science

    At a given temperature and pressure, the volume of a gaseous sample is directly proportional to the moles of gas (volume = C * moles, where C is a constant). Assuming that the tempreature and pressure is the same for the reaction of magnesium with HCl(aq)

    asked by Amy on March 14, 2013
  90. chemistry

    An orgnaic compound contains C, H, No, and O. Combustion of 0.1023 g of the compound in excess oxygen yielded 0.2766 g of CO2 and 0.991g of H2O. A asample of 0.4831 g of the compound was analyzed for nitrogen by the Dumas method. At STP, 27.6 mL of dry

    asked by kaliegh on December 9, 2007
  91. Statistics

    he level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.7 grams per mile and standard deviation 0.19 grams per mile . (a) What sample size is needed so that the standard deviation of the sampling distribution is 0.01

    asked by zoolo on March 5, 2016
  92. Statistics

    The level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.9 grams per mile and standard deviation 0.15 grams per mile . (a) What sample size is needed so that the standard deviation of the sampling distribution is 0.01

    asked by Terra on January 12, 2012
  93. chemistry

    Changing 1 mol of Mg(s) and 1/2 mol of O2 (g) to gaseous atoms requires a total of approximately 150kJ of energy. The first and second ionization energies of Mg are 737kJ/mol and 1450kJ/mol respectively. The first and second electron affinities of Oxygen

    asked by Insolvable question on November 22, 2016
  94. physics

    a)find the charge to mass ratio for an electron accelerated through 600v in a magnetic field of strength 45mT where the speed of the electrons is 1.4*10^7m/s b)what is the percentage difference b/n your result and the accepted ratio with the value

    asked by ruth on March 10, 2016
  95. science

    Calculate the pH of a solution of ammonium acetate (CH3COONH4) 0,85M knowing that for NH3 Kb = 1,79x10-5 and CH3COOH Ka = 1,76x10-5 and commented on the result obtained. Then calculate the percentage of acetic acid product at equilibrium

    asked by frankscience on May 1, 2016
  96. Algebra

    The function f(x)=(250x)/(100-x) models the cost, f(x), in millions of dollars, to remove x% of a river's pollutants. Use this functions to solve: If the government commits $750 million for this project, what percentage of the pollutants can be removed?

    asked by Court on January 3, 2011
  97. math

    1.64g of a mixture of cac03 and mhco3 was dissolved in 50ml of 0.8M hcl. The excess of acid required 16ml of 0.25M naoh for neutralization. Calculate the percentage of cac03 and mgc03 in the sample Who helps me

    asked by Fai on December 21, 2013
  98. Algebra

    The function f(x)=(250x)/(100-x) models the cost, f(x), in millions of dollars, to remove x% of a river's pollutants. Use this functions to solve: If the government commits $750 million for this project, what percentage of the pollutants can be removed?

    asked by Court on January 3, 2011
  99. business

    five companies contribute different amounts to a local charity. which visual could best illustrate the percentage of all the monies collected that each companys cntribution represented table bar chart line graph pie chart

    asked by terrie on December 10, 2010
  100. Probability and Statisics

    Suppose that 20% of the adult women in the United States dye or highlight their hair. We would like to know the probability that a SRS of size 200 would come within plus or minus 3 percentage points of this true value. In other words, find probability that

    asked by Rita on June 20, 2016