1. chemistry

    'Manganese(III) fluoride, MnF3, can be prepared by the following reaction: 2MnI2(s) + 13F2(g) ? 2MnF3(s) + 4IF5(l) If the percentage yield of MnF3 is always approximately 56%, how many grams of MnF3 can be expected if 10.0 grams of each reactant is used in
  2. chemistry

    treatment of a 0.3203g sample of impure soduim chloride with an excess of AgNo3 resulted in the formation of 0.7331g of AgCl. how many grams of sodium chloride were in the sample? What is the weight percentage of NaCl in the sample?
  3. chemistry

    treatment of a 0.3203g sample of impure soduim chloride with an excess of AgNo3 resulted in the formation of 0.7331g of AgCl. how many grams of sodium chloride were in the sample? What is the weight percentage of NaCl in the sample?
  4. chemistry

    treatment of a 0.3203g sample of impure soduim chloride with an excess of AgNo3 resulted in the formation of 0.7331g of AgCl. how many grams of sodium chloride were in the sample? What is the weight percentage of NaCl in the sample?
  5. Understanding percentages

    Check my answer,, A store advertises a shirt at 25% off the original price of $44. What is the sale price? MY ANSWER: $33.00 What is the percentage increase in high school enrollment from 1,165 students to 1,320? MY ANSWER: 13.3%
  6. Chemistry

    Bacterial digestion is an economical method of sewage treatment. 5CO2(g) + 55NH4+(aq) + 76O2(g) -> C5H7O2N(s) + 54NO2-(aq) + 52H2O(l) + 109H+(aq) bacterial tissue The above reaction is an intermediate step in the conversion of the nitrogen in organic
  7. Chemistry

    Bacterial digestion is an economical method of sewage treatment. 5CO2(g) + 55NH4+(aq) + 76O2(g) -> C5H7O2N(s) + 54NO2-(aq) + 52H2O(l) + 109H+(aq) bacterial tissue The above reaction is an intermediate step in the conversion of the nitrogen in organic
  8. Chemistry please help :)

    A 1.10 sample of dry ice is added to a 745 mL flask containing nitrogen gas at a temperature of 25.0 degrees C and a pressure of 735 mm Hg . The dry ice is allowed to sublime (convert from solid to gas) and the mixture is allowed to return to 25.0 degrees
  9. Chemistry-gases

    Nitrogen dioxide reacts with water and oxygen in the atmosphere to produce acid rain. 4NO2(g) + 2H2O(g) + O2(g) = 4HNO3(g) Assuming that the temperature and the pressure remain constant, calculate the volume of air at 1 atm, 20 C, necessary to dilute the
  10. Chemistry-gases

    Nitrogen dioxide reacts with water and oxygen in the atmosphere to produce acid rain. 4NO2(g) + 2H2O(g) + O2(g) = 4HNO3(g) Assuming that the temperature and the pressure remain constant, calculate the volume of air at 1 atm, 20 C, necessary to dilute the
  11. english

    i wrote thins hoping that someone can help me with giving me some ideas on the topic this is what they want In a total of 200 words, write two paragraphs with about how interest rates affect our purchasing decisions. Identify the topic sentence in each by
  12. englisj

    i wrote thins hoping that someone can help me with giving me some ideas on the topic this is what they want In a total of 200 words, write two paragraphs with about how interest rates affect our purchasing decisions. Identify the topic sentence in each by
  13. CHEMISTRY

    This is STOICHIOMETRY. Please i need help in the worst way. I don't understand this at all and it is due tomorrow, please i need someones help who really understands this. #1.aluminum nitrite and ammonium chloride react to form aluminum chloride, nitrogen
  14. Math PROBABILITY part 1

    Anna mixes the letters S, E, L, E, C, T, E, and D thoroughly. Without looking, Mary draws one letter. Expressed as a fraction, decimal, and percentage, what is the probability that E will NOT be the letter Mary selects? A. 3/8, 0.375, 37.5% B. 8/5, 1.6,
  15. Chemistry

    What volume of nitrogen gas can be produced from he decomposition of 37.6 L of ammonia with both gases measured at 725 degree celsius and 5.05 pressure? In the reaction in 71 what total volume of gas at 667 celsius and 11.3 atm can be produced by the
  16. chemistry

    A 0.0677 g sample of magnesium metal reacted with excess hydrochloric acid solution to produce 69.9 mL of hydrogen gas. The gas was collected over water at 21.0° C. The levels of water inside and outside the gas collecting tube are identical (meaning that
  17. Music

    23. If the fourth chord of a note is a seventh above the root, the chord is: a. a 7th chord b. a triad c. non-tertian d. a 4th chord Not sure 33. The inversion of triads can be written with roman numerals and a. letters b. small numbers c. percentage signs
  18. chemistry

    the percentages of carbon,hydrogen and oxygen in vitamin c were determined by burning a sample weighing 2.00mg,the masses of carbondioxide and water formed are 3.00mg and 0.81mg respectively.from these information,find the percentage of each element and
  19. Consumers Math

    I don't want the answer to this question, but if someone could please tell me how to work it out, that would be great and I could finish it on my own. Thank you very much:) Question- Your station charges $15.95 for an oil change. As a promotion you sell
  20. Chemistry

    A 10.0 gram sample of a mixture of CH4 and C2H4 reacts with oxygen at 25°C and 1 atm to product carbon dioxide gas and liquid water. If the reaction produces 520 kJ of heat, what is the mass percentage of CH4 in the mixture? PLEASE HELP! I do not know
  21. chemistry repost

    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. ( i did
  22. Constitution

    Judicial review has been used to invalidate approximately what percentage of all federal laws? A. 1 B. 5 C. 20 D. 50 is it C 2. When a case is improperly removed from state court, and then returned to state court, the process is referred to as: A. remand.
  23. Chemistry

    When 1.63 g sample of an unknown hydrocarbon is completely burned in oxygen, 4.97 g of CO2 are produced. What is the percentage by mass of hydrogen in this hydrocarbon? THANK YOUU Found out the formula: 4CH+5O2--> 4CO2+2H2O then found out the moles of
  24. Chemistry

    Please check the following. 1. What compound is sodium sulfite? My answer:Na2SO3 2. Which element is a noble gas? a. N2 b. Cl2 c. Xe d. I2 My answer: c 3. Which element is most likely to form a cation with a 2+ charge? a. S b. P c. Be d. Al My answer: c 4.
  25. Chemistry

    Please check the following. 1. What compound is sodium sulfite? My answer:Na2SO3 2. Which element is a noble gas? a. N2 b. Cl2 c. Xe d. I2 My answer: c 3. Which element is most likely to form a cation with a 2+ charge? a. S b. P c. Be d. Al My answer: c 4.
  26. Chemistry

    A compound containing only C, H, and N yields the following data. (i) Complete combustion of 34.8 mg of the compound produced 33.3 mg of CO2 and 40.9 mg of H2O. (ii) A 66.3-mg sample of the compound was analyzed for nitrogen by the Dumas method, giving
  27. computer studiea

    : 88% 100% 100% 100% 16% what is overall percentage
  28. Math

    A balloon is slowly losing air , decreasing from a volume of 75cubic cubic inches to 55 cubic inches.What is the balloons percentage decrease in volume
  29. Math

    If someone earns $960 interest over 4 year period on a $6,000 investment, how do I solve this to find the percentage of interest per year. I know it is 4%, I just can't figure out how to show the math.
  30. chemistry

    Copper (II) flouride contains 37.42% F by mass. Use this percentage to calculate the mass of flourine (in grams) contained in 35.6 g of copper (II)fluoride. --- How many grams of Cl are present in 55g of CFCl3?
  31. Life science

    A pure-breeding black coat cat was crossed with a hybrid black coat cat. (a)Represent the diagrammatically .(b)What percentage of the offspring
  32. math

    Farmer Rex planted 48 rows each having 30 corn trees. a) How many corn trees did he plant? b) 1006 plants grew. What percentage of the plants did not grow?
  33. chemistry

    A sample consist only NaCl and NaBr has amass of 0.7648gm. This sample is place in solution in which excess of silver is added which forma precipitate the AgCl and AgBr has amass of 1.5758 gm . what's the percentage of Cl and Br in original sample ?
  34. Math, due tonight!

    Assume that all linear dimensions of an animal increase by 12%. Then the animal will have the same shape. How do the surface area, the volume and the weight (under assumption of constant specific gravity) increase? Give the percentage of the increase.
  35. ALGEBRA 2

    The Rattlesnakes football team plays a different opponent every week. So far this season, the Rattlesnakes have won 3 games out of 6. Which equation models the number of consecutive games the Rattlesnakes must win in order to increase their winning
  36. CHM 105

    Vinegar contains ethanoic acid (CH3OOH).titration of 3.00g of vinegar with 0.12M NAOH Solution requires 23.0cm3 to reach the equivalent ppoint.what is the weight percentage of the ethanioc acid in vinegar?
  37. chemistry

    Kc=5.85x10^-3 at 25 degrees C for the reaction N2O4(g)<-->2NO2(g) fifteen(15.0) grams of N2O4 is confined in a 5.00-L flask at 25 degrees C. Calculate(a) the number of moles of NO2 present at equilibrium and(b) the percentage of the original N2O4
  38. math

    Some households were questioned about the numebr of can openers they possessed. The results are indicated in the frequency table shown below: # of openers; 0,1,2,3,4 and frequency;1,8,11,7,1 a. does this dtat appear to be skewed? explain b. How many
  39. math

    A sales manager was given a bonus of $6,090 on the year's sales of $400,000. When answering the following questions, please make sure your final answers are in percentage form and are accurate to 2 decimal places. For example 34.56%. a) What was the bonus
  40. chemistry

    Manganese(III) fluoride, MnF3, can be prepared by the following reaction: 2MnI2(s) + 13F2(g) → 2MnF3(s) + 4IF5(l) If the percentage yield of MnF3 is always approximately 51%, how many grams of MnF3 can be expected if 40.0 grams of each reactant is
  41. 6th grade algebra

    a) Kendric makes 4 out of every 5 baskets he throws. What is the probability he will make his next shot as a percentage? MULTIPLE CHOICE b) If Marcia walks 4 1/4 miles before work and 5 6/8 miles after work. How many miles did she walk for the day? A 9
  42. Chemistry

    1. Weight loss from quick-weight-loss diets is generally loss of __________. A) fat B) carbohydrates C) muscle D) water*** 2. What is the recommended maximum percentage of a persons calorie intake should come from saturated fats? 0-5% 15-18% 7-10%***
  43. math

    Data collected from those who reported their credit card debt showed that the lowest average annual percentage rate on its credit cards was 0.019. Represent this as a percent. The lowest APR on its credit cars was __% ?
  44. Chemistry 2

    The bottle of bleach lists the percentage of sodium hypochlorite as 6.0%. If the density of commercial bleach is 1.084 g/mL, how many mL of .150 M sodium thiosulfate is required to reach the endpoint in a titration if a student analyzed a 2.0 mL sample of
  45. math

    27 letters in 1988, 18 letters in 1989 what is % of change? *need to know how you arrive at the answer Didide the change (-9) by the original value (27), and convert that fraction to a percentage. I'll be glad to critique your answer.
  46. Chemistry

    A 1.00x10-6g sample of nobelium- 254, has a half-life of 55 seconds after it is formed. What is the percentage of nobelium-254 remaining at the following times? (a) 5.0 min after it forms (b) 1.0 h after it forms
  47. Statics

    In a first semester unit there are four tests each of equal weight i.e. each worth 25%. Your average on the first three tests has been 62%. You need to get an overall average of 65% to proceed to the second semester. What percentage should you try to get
  48. chemistry

    A .500 g sample of impure CaO (a solid) is added to 50.0 mL of 0.100 M HCl. The excess HCl is titrated by 5.00 mL of .125 M NaOH. What is the percentage of CaO in the sample?
  49. chemistry

    A mosquito fed on a solution containing phosphorous-32 is released. Phosphorous-32 has a half-life of 14 days. When the mosquito is recaptured 28 days later, what percentage of the original Phosphorus-32 will remain?
  50. Science

    A solution is prepared by dissolving 11gm glucose in 200 cm3 water at 30°c. What is the mass percentage of glucose in solution? The density of water 30°c is 0.996 glcm3?
  51. chemistry

    the mass of a certain mixture of BaO and CaO is found to be exactly one half that of the mixed sulfates formed from it by the action of H2SO4. calculate the percentage of BaO and CaO in the mixture.
  52. physics

    A satellite is placed in orbit 100 km above the surface of the earth (radius = 6370 km, mass = 5.98 x 1024 kg). What is the value of the acceleration of gravity at that altitude as a percentage of the acceleration at the surface of the earth?
  53. Math

    Children 13 and younger make up 1/5 of the population in the U.S. What percentage of the population is older than 13 A.80% B.60% C.40% D.20% D? According to a survey 3 out o5 5 students bring their own lunch to school. What percent of students bring
  54. Corporate Finance

    You have just taken a 30-year mortgage loan for $200,000. The annual percentage rate on the loan is 8%, and payments will be made monthly. Estimate your monthly payments.
  55. Chemistry

    Hydrogen gas, H2, reacts with nitrogen gas, N2, to form ammonia gas, NH3, according to the equation 3H2(g)+N2(g)→2NH3(g) PArt 1: How many grams of NH3 can be produced from 3.26 mol of N2 and excess H2. Part 2: How many grams of H2 are needed to produce
  56. Chemistry

    An impure sample of substance X melts at about 113 degress. Which of the substances could be X and state y Resorcinal 111 degrees Catechol 105 Nitrophenol 114 Butanamide 115 I think it is either catechol or resorcinol because as stated the higher the
  57. biology

    I have some questions that relate to table 2.1 which lists the chemical elements that occur naturally in the human body. Similar percentages of these elements are found in most living organisms. a. In what abiotic (non-life) chemical forms are these
  58. Physics

    Many people mistakenly believe that the astronauts who orbit the Earth are "above gravity." Calculate g for space shuttle territory, 290 kilometers above the Earth's surface (dashed line in sketch). Earth's mass is 6 1024 kg, and its radius is 6.38 106 m
  59. Science

    1.What is the genetic code? (1 point) The order of amino acids in proteins makes up the genetic code. The order of amino acids in mRNA makes up the genetic code. The order of nitrogen bases in tRNA makes up the genetic code. The order of nitrogen bases in
  60. math

    Find the effective rate corresponding to the given nominal rate. (Round your answer to the nearest hundredth of a percentage point.) (a) 7%/year, compounded daily % (b) 6%/year, compounded monthly %
  61. Statistics

    Suppose that IQ scores have a bell-shaped distribution with a mean of 99 and a standard deviation of 12. Using the empirical rule, what percentage of IQ scores are less than 87? Please do not round your answer. 87-99 = -12/12 = -1 I get stuck here. I know
  62. goechemistry-science

    i ppted out iron(111) form a solution and weighed the ppt. then dissolved the ppt in a solution and run in an aas and get the concentration. how can i get the percentage concentration of fe3+ given that it is from fe(oh)3
  63. Chemistry

    a student conducts and experiment by reacting 39.6g CuSO4 with an excess of MgS. The reaction yields 9.5599g CuS. What is the percentage yield? MgS+CuSO4=CuS+MgSO4
  64. Maths Percentage

    DRICSIN 3G MOBILE PHONE: $980 NOW ENJOY 10% DISCOUNT!<------ Ramesh saw the following advertisement. How much would Ramesh pay for the mobile phone of he paid 7% GST on the discounted prices?
  65. Chemistry

    Iron is extracted from the mineral magnetite, Fe3O4: Fe3O4 (s) + 2 C (s)  3 Fe (s) + 2 CO2 (s) A 35.0 g sample of magnetite is reacted with 4.0 g of carbon, and 15.0 g of iron is produced. Determine the percentage yield of this reaction. (6)
  66. Maths

    By selling a sofa set at 85% of the labelled price, Apex furniture earned a profit of 13.33% when it sold the sofa set for Rs 17,000.What will be the profit percentage if the discount is not offered?
  67. Pre-Algebra

    In 2002 the rate for a first class U.S. postage stamp increased to $0.37. This represent a $0.34 increase since 1917. What is the percentage increase of postage since 1917? Solve the problem using a proportion.
  68. statistics

    The life span of the battery pack is known to be Normally distributed with a mean of 250 hours and a standard deviation of 20 hours. How to find the percentage of the battery packs lasting more than 250 hrs.
  69. physics

    a rubber ball is dropped from a height of 5m. After the 5th bounce, the ball only comes back up to 0.76m in height/ Find the percentage loss of kinetic energy for each individual bounce.
  70. Math

    Find the effective rate corresponding to the given nominal rate. (Round your answer to the nearest hundredth of a percentage point.) (a) 4%/year, compounded quarterly ? % (b) 3%/year, compounded monthly ? %
  71. chemisty

    Calcium carbonate can be decomposed by heating according to the equation Below. WHat is the percentage yield of calcium oxide in this reaction if 12.6g of CaO is obtained when 25.9g of CaCO3 is heated ? CaCO3(S) -> CaO (s) + CO2 (g)
  72. Math

    Find the effective rate corresponding to the given nominal rate. (Round your answer to the nearest hundredth of a percentage point.) (a) 4%/year, compounded quarterly ? % (b) 3%/year, compounded monthly ? %
  73. Math Need Help

    The price of an item changed form $140 to $100. Then later the price increase again from $100 to $140. Which of the two changes was larger in percentage in term and how much percent?
  74. Math

    Jackie buys a basket for $6, 2 pounds of apples for $3.50 per pound, and 2 pounds of oranges for $3.50 each per pound. The tax for the whole purchase is $1. Express the tax as a percentage.
  75. STATISTICS

    the percentage of adults who have at some point in their life been told that they have hypertension is 23.53%. If 8 adults are randomly selected, find the probability that between 2 and 4 of then inclusive have been told that they have hypertension
  76. Pre-Algebra

    A chess club with 40 members is electing a new president. Lisa received 16 votes. What percentage of the club members voted for Lisa?
  77. Chemistry

    0.5g sample of bronze containing Zn is dissolved in 100ml of acid. An aliquot of 25ml requred 10.25ml of EDTA. What is the percentage of zinc in the bronze sample?
  78. MATH

    At a party, married people came with their husbands or wives. if half the women and 1/6 of the men in the party were single, what percentage of the people in the room were married?
  79. Statistics

    Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 34.1% 84.0% 15.7% my answer was 13.6 13.6% is this correct 97.6%
  80. Math 221

    A chess club with 55 members is electing a new president. Ali received 33 votes. What percentage of the club members voted for Ali?
  81. math

    A district mathematics test for all third graders had a normal distribution with a mean of 74 and a standard deviation of 11. What percentage of the third graders tested scored with +1 and -1 standard deviation of the mean?
  82. economics

    If there has been a 10 percent increase in consumer income between two periods, what was the percentage change in the demand for foreign travel. The income elasticity for foreign travel is 1.93
  83. statistics

    the ages of the members of a gym have a mean of 44 years and a standard deviation of 12 years. what can you conclude from Chebyshev's theorem about the percentage of gym members aged between 26 and 62?
  84. statistics

    Given that the general population is normally distributed on a standard scale measuring math aptitude with Mean = 50 (s.d. = 10), approximately what percentage of the population has a math aptitude score between 40 and 60?
  85. Statistics

    the average numbers of hours a cat sleep is approximately normally distributed with a mean of 15 hours and a standard deviation of 1.7 hours; what percentage of cats sleep between 13 and 18 hours
  86. Statistics

    A district mathematics test for all third graders had a normal distribution with a mean of 74 and a standard deviation of 11. What percentage of the third graders tested scored with +1 and -1 standard deviation of the mean?
  87. percents

    A company gives raises once a year. Amir's present salary is $12,000. His manager would like to raise his salary to $84,000. What percentage raise would he be recieving.
  88. Chemistry

    We're doing gas problems in chemsitry. I have no idea where to even begin on this problem: Air is 20% oxygen and 80% nitrogen. What is the mass of air in an automobile tire of 19.7 L and internal pressure of 46.7 PSI at 24 degrees celsius? (That pressure
  89. Chemisty

    Iodine monobromide and ammonia react to produce nitrogen triiodide and ammonium bromide. (a) Balance the chemical equation for this reaction. (Use the smallest possible whole numbers. Enter 1 where appropriate. Do not leave any answer box blank.) . IBr(s)
  90. Math

    There are 100 apples in a bag 43 of them are red and the rest are green apples what percentage of the apples are green
  91. Math

    There were 400 seats in a concert hall. 360 seats were occupied . What percentage of the seats were not occupied ?
  92. chemistry

    Element x is composed of isotopes x-56 mass 56.0 u and x-59 mass 59.0 u. What is the percentage abundance of each of these isotopes if the atomic mass is 57.3 u?
  93. chemistry

    A solution contain 20 gram of NaCl in 95 cm3 solution the density of the solution is 1.25 g cm-3 what is the mass percentage of Nacl
  94. chemistry

    A 20.9 g sample of nitrogen gas combines completely with 4.5 g of hydrogen gas to form ammonia. What is the mass of ammonia formed? A 12.7 g sample of X combines with a 24.4 g sample of Y to form the compound XY2. What is the mass of the reactants?
  95. Chemistry- Dr. Bob

    Please check the following. 1. What compound is sodium sulfite? My answer:Na2SO3 2. Which element is a noble gas? a. N2 b. Cl2 c. Xe d. I2 My answer: c 3. Which element is most likely to form a cation with a 2+ charge? a. S b. P c. Be d. Al My answer: c 4.
  96. Math

    In January, the price of a kilogram of potatoes at Supermarket X was $3.20. In May, a kilogram of the same type of potatoes cost $2.99. Find the percentage decrease in price. Express your answer correct to 1 decimal place.
  97. statistics

    The test scores of students in a class test have a mean of 65 and with a standard deviation of 8. What is the probable percentage of students scored more than 70? Please check work 70-65/8 = .625 = .2357 = 1.-.2357 = .7643 ANSWER 76% ????
  98. Math

    Im going to try another percentage problem. Will you please double check me. Thanks for all your help! 2580/4440=.581081081 Change to percent and round to nearest tenth. .581081081*100=58.108 rounded to nearest tenth is 58.1%
  99. Statistics

    1. The mean and standard deviation of the grades of a group of students who took an economic exam  were 69 and 7, respectively. The grades have a mound-shaped distribution. According to the Empirical Rule,    a) Approximately 68% of the grades were
  100. math

    You sell and service vacuum cleaners. Your price on a particular model is $125. However, to get a service contract, you offer to sell it for $115. How much discount are you giving as a percentage of price (to the nearest tenth)?