1. science

    Granite is an intrusive, felsic rock, which may be produced by partial melting or fractional crystillisation. Explain how these processes can produce felsic magmas from more mafic parent magmas. any ideas please Wouldn't the presence of magnesium and iron
  2. chemistry

    ​An empty glass container has a mass of 418.634 grams. It has a mass of 419.514 grams after it has been filled with nitrogen gas at a pressure of 790 mmHg and a temperature of 15oC. When the container is evacuated and refilled with a certain element
  3. chemistry

    A) what is the molar fraction of each gas in a mixture of 6g of hydrogen H2 and 7g of nitrogen N2 ? B) what is the total pressurd exerted by the above mixture in a volume of 15 l at a temperature of 0ºc ? C) what is the partial pressure of each gas in the
  4. Physics

    31m/s is a typical highway speed for a car. At what temperature do the molecules of nitrogen gas have an rms speed of 31m/s? T=[(x^2)*m]/3k so x=31m/s m=N2=2*14=28g=.028kg k=1.38e^-23..I'm keep getting 6.333651477e^10...which is incorrect. What am I
  5. Science (check my answers)

    11. How do fossil fuels contribute to air pollution? A. By releasing carbon dioxide into the air*** B. By recycling oxygen C. By reversing the greenhouse affect D. By releasing nitrogen into the air
  6. chemistry

    a compound contains 5.2% by mass Nitrogen. It also contains carbon, hydrogen and oxygen. Combustion of 0.085g of the compound produced 0.224g of carbon dioxide and 0.0372g of water. Calculate the empirical formula of the compound.
  7. Biology

    I feel stupid, but seriously, I used to be better at Science than Math. Now it's the other way around. Bacterial DNA is (a) a closed loop (b) encased in a capsule (c) linear (d) found in the nucleus. The glycocalyx helps bacteria (a) survive unfavorable
  8. chemistry

    Given a sufficient supply of nitrogen gas, how many moles of ammonia gas will be produced from 10.8 moles of hydrogen gas?
  9. Chemistry

    Benzene, C6H6, reacts with nitric acid, HNO3. Two products are formed, one of which is water. The second product has a molar mass of 213 grams. The second product is composed of 33.8% carbon, 1.42% hydrogen, 19.7% nitrogen, and 45.1% oxygen. Write a
  10. Chem Help Please!!!

    For each of the pairs of elements below give the formula for the simplest compound to be formed from them and explain the basis of your decision and note if the bond(s) formed are ionic or covalent. a) sodium and fluorine b) nitrogen and hydrogen c)
  11. math (statistics)

    The following table shows the percentage of individuals in each age group who use an online tax program to prepare their federal income tax return. AGE ONLINE TAX PROGRAM (%) 18-34 16 35-44 12 45-54 10 55-64 8 65+ 2 Suppose a follow-up study consisting of
  12. Chemistry

    N2 + O2 -> 2NO enthalpy change = +180.6kJ c) what is the enthalpy change for the formation of one mole of nitrogen monoxide? Okay, I know this question is super easy, but I don't know how to do it; if someone could please give me a detailed explaination
  13. science

    Burning fossil fuels like natural gas and coal releases___. a.)trapped air layers b.) nitrogen, oxygen, and carbon compounds c.)sulfurous smog d.) ultraviolet radiation confused a little... do not understand what Sulfurous smog is? thank you
  14. Physics

    Two pans of a balance are 50cm apart. If the fulcrum is displaced by 1cm what percentage is the true weight marked up? the answer i got was 1.3%, please help if wrong (which it probably is).
  15. statistics

    CALCULATE THE PERCENTAGE OF CASES THAT FALL BETWEEN THE SCORES 120 AND 110 ON A NORMALLY DISTRIBUTED iq TEST WITH A MEAN OF 100 AND A STANDARD DEVIATION OF 10
  16. Finance

    I need help computing the Annual percentage yield (APY) for a savings account that earned $56 in interest on $800 over 365 days? HELP PLEASE!
  17. College Physics

    After 2.5 time constants, what percentage of the final voltage, emf, is on an initially uncharged capacitor C, charged through a resistance R?
  18. microeconomics

    Question 7 of 20 5.0 Points Suppose that the elasticity of demand for a product is 0.5 and quantity demanded increases by 20%. What must the percentage decrease in price have been?
  19. science

    The least count of a screw gauge is 0.001cm.the diameter of wire measured by it is 0.225cm.find out percentage error in the measurement.
  20. Finance

    I need help computing the Annual percentage yield (APY) for a savings account that earned $56 in interest on $800 over 365 days? HELP PLEASE!
  21. Accounting

    What impact does amt have on the decision to whether to use either the percentage of completion method or completed contract for reporting profit on longterm contracts?
  22. math

    The length and breadth of a rectangular paper were measured to be the nearest centimeter and found to be 18 cm and 12 cm respectively. Find the percentage error in its perimeter
  23. math

    a new physician saw 841 clients during the first year of her practice and 1,072 the second. which represents the percentage increase in client volume? a. 22% b. 27% c. 78% d. 127%
  24. math

    The length and breadth of a rectangular paper were measured to be the nearest centimeter and found to be 18 cm and 12 cm respectively. Find the percentage error in its perimeter.
  25. hazard bctcs

    According to Chebychev's theorem, what percentage of a distribution will be within k = 3.7 standard deviations of the mean? (Give your answer correct to one decimal place.)
  26. Stats

    Given that a sample is approximately bell-shaped with a mean of 60 and a standard deviation of 3, the approximate percentage of data values that is expected to fall between 54 and 66 is 75% 95% 68% 99.7%
  27. math

    The length and breadth of a rectangular paper were measured to be the nearest centimeter and found to be 18 cm and 12 cm respectively. Find the percentage error in its perimeter.
  28. science

    a can potatoes has the following data: recall 4-9system carbs=22 fat is 10 grams and protien is 13 find the percentage of each if the calories = 275
  29. math

    The length and breadth of a rectangular paper were measured to be the nearest centimeter and found to be 18 cm and 12 cm respectively. Find the percentage error in its perimeter.
  30. Math

    neha scored 75% in science,95% in maths and 70% in english. If the max. marks in these subjects were 80,100and 70,respectively. find her aggregate percentage.
  31. Grade 12 Bio Please try to help me

    If a life-form has six different bases-ABCDEFG. the percentage composition of A,B and C is same as EFG. Hypothesis the structure of the nucleic acid.
  32. Math

    The length and breadth of a rectangular paper were measured to be the nearest centimeter and found to be 18 cm and 12 cm respectively. Find the percentage error in its perimeter.
  33. chemistry

    how does band gap energy work? when dealing with voltages and color change from LEDs[depends on phosphorous percentage]
  34. MATH

    Money in a bank account that compounds interest by some percentage acts _______.? A.linearly B.exponentially C.negatively D.like a fraction Is it B?
  35. computer

    Write an algorithm to enter marks of three subject for 100 students and find average and percentage if age is greater than 20 and less than 25
  36. Algebra

    For real numbers a and b, define a%b=sqrt(a^2+b^2). What is the value of (5%12)%((-12)%(-5))? The percentage is just a random sign the problem had a diamond instead, I just couldn't find any other symbol.Thank you!
  37. Chemistry

    What is the percentage of gas (C2H2) formed when 2.66g of calcium carbide (CaC2) reacts completely with 50g water?
  38. Math

    Does anyone know the old formula to calculate a hourly raise from a percentage; I totally forgot. The employee makes $10.50 an hour and is receiving a 1.1% increase.
  39. Statistics

    Given that a sample is approximately bell-shaped with a mean of 60 and a standard deviation of 3, the approximate percentage of data values that is expected to fall between 54 and 66 is
  40. Us History

    please help me! what was the percentage of african slaves in the north, south,east, and west in the years of 1820,1835,1845, and 1860??
  41. Physics

    If the length of pendulum is 0.8+/-0.01m and time peroid is 2.5+/-0.012 sec. Then percentage error in acceleration due to gravity will be
  42. pharmacy math

    15 grams of potassium chloride is diluted in 2 liters of sterile water for injection what is the final percentage strength
  43. statistics

    Given that a sample is approximately bell-shaped with a mean of 60 and a standard deviation of 3, the approximate percentage of data values that is expected to fall between 54 and 66 is
  44. Chemistry

    Calculate the molar concentration for each of the following. a)The concentration of a brine solution containing 225 g for pure sodium chloride dissolved in 4.00 L of solution. b)The volume that must be added to 4.2 mol of magnesium chloride to make a 0.045
  45. math

    The following table gives the free throws attempted (FTA) and the free throws made (FTM) for the top five players in the NBA for a recent season. Calculate the free throw percentage for each player by writing the FTM over the FTA and converting this
  46. Chemistry

    Each Rolaid tablet contains 550mg of calcium carbonate and 110mg of magnesium hydroxide. Kroger Extra Strength antacid tablets contain 750mg of calcium carbonate per tablet. What is the neutralizing ability per gram for each tablet? Your answer should be
  47. physics

    A WEATHER BALLOON IS TO OPERATE WHERE THE DENSITY OF AIR IS 0.9Kg/m3. THE BALLOON HAS A VOLUME OF 20cm3 AND IS FILLED WITH NITROGEN WITH DENSITY 0.09Kg/m3. IF THE BALLOON BAG WEIGHS 118N, WHAT LOAD CAN IT SUPPORT AT THIS ALTITUDE?
  48. Dissociation Equations Answer Check

    1. Write the equation for the dissolution of potassium iodide in water. KI(s) + H20 --> K+ (aq) + I- (aq) 2. Write the equation for the dissolution of magnesium bromide in water. MgBr2(s) + H20 --> Mg2+ (aq) + 2Br- (aq)
  49. Chemistry

    The following replicate values were reported for the concentration of magnesium chloride, MgCl2, in mol/L. What value should be reported as the mean concentration of the chloride ion, Cl-, converted to ppm? (You may use the simplified definition of ppm.)
  50. science

    The following replicate values were reported for the concentration of magnesium chloride, MgCl2, in mol/L. What value should be reported as the mean concentration of the chloride ion, Cl, converted to ppm? (You may use the simplified definition of
  51. chemistry

    A 2.000g sample of magnesium was burned in air to form an oxide. After the product was purified it was found to have a mass of 3.317g. What is the empirical formula for the product? I know how to find a empirical formula, I just don't understand what
  52. math

    The following table gives the free throws attempted (FTA) and the free throws made (FTM) for the top five players in the NBA for a recent season. Calculate the free throw percentage for each player by writing the FTM over the FTA and converting this
  53. Math

    Please help The following table gives the free throws attempted (FTA) and the free throws made (FTM) for the top five players in the NBA for a recent season. Calculate the free throw percentage for each player by writing the FTM over the FTA and converting
  54. Chemistry

    Nitrogen and hydrogen gases react to form ammonis gas as follows: N2(g)+3H2(g)-->2NH3(g) At a certain temperature and pressure, 1.2L of N2 reacts with 3.6L of H2. If all the N2 and H2 are consumed, what volume of NH3 at the same temperature and pressure
  55. Chem-Help Please!!!

    a correction needs to be made to the calculations for real gases as compared to ideal gases. apply these corrections and calculate the real pressure expected for 5 mole of nitrogen in a 1.5L container at a temp. of 20C. Note: I tried to find right formula
  56. Chemistry Balancing Equations

    I really need help with balancing these equations: PLEASE HELP!! 1. Sodium Hydrogen Sulfite reacts with hydrochloric acid to produce sulfur dioxide gas, water and sodium chloride 2. Sodium nitrate reacts with hydrochloric acid to produce nitrogen monoxide
  57. Computer programming

    Submit pseudocode for the following programming exercise: Fat Gram Calculator 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 are not less
  58. Programming

    Submit pseudocode and a flowchart for the following programming exercise: Fat Gram Calculator 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
  59. math-statistics

    Assume the body temperature of healthy adults are normally distributed with a mean of 98.20 degrees F (based on data from the Uniservity of Maryland researchers).a. If you have a body temperature of 99.oo degrees F, what is your percentile score? b.
  60. Chemistry

    At 103◦C, the pressure of a sample of nitrogen is 1.89 atm. What will the pressure be at 275◦C, assuming constant volume? Answer in units of atm
  61. chemistry

    t 103 ◦ C, the pressure of a sample of nitrogen is 1 . 89 atm. What will the pressure be at 275 ◦ C, assuming constant volume? Answer in units of atm
  62. Nuclear Physics

    Radioactive Carbon 14 (atomic number 6) is produced in the atmosphere when a neutron is absorbed by Nitrogen 14 (atomic number 7). Write the reaction and write its Q-value.
  63. Chem

    Which of the following pairs of elements are likely to form an ionic compound? lithium and chlorine sodium and potassium phosphorus and chlorine sodium and nitrogen argon and potassium
  64. chemistry

    20g of nitrogen gas and 10g of helium gas are placed together in a 5L container at 25C . Calculate the partial pressure of each gas and the total pressure of the gas mixture.
  65. science

    Ammonia, NH3, can be made by reacting nitrogen and hydrogen and the equation is N2 + 3H2 --> 2NH3 How many moles of NH3 can be made if 12 moles of H2 react with enough N2? mol
  66. Chemistry

    I could use some help please. Ammmonia, NH3, can be made by reacting Nitrogen with Hydrogen. N2+3H2=2NH3 How many moles of NH3 can be made if 7.5 moles of H2 react eith enough N2? Thank-you in advance for any help
  67. chem

    At 119 degrees C, the pressure of a sample of nitrogen is 1.94 atm. What will the pressure be at 282 degrees C, assuming constant volume? Answer in units of atm
  68. Chemistry

    At 906 K, 3.60 mol of ammonia gas is placed into 2.00 L vessel and allowed to decompose to the elements nitrogen and hydrogen. If Kc = 6.56 E-3 for this reactions at this temperature, calculate the equilibrium concentration of each component at
  69. chemistry

    he decomposition of nitrogen dioxide at a high temperature is second order in this reactant. NO2(g) NO(g) + 1/2 O2(g) The rate constant for this reaction is 3.40 L/mol·min. Determine the time needed for the concentration of NO2 to decrease from 2.30 mol/L
  70. AP Chemistry

    Given: 2N2(g) +O(2) --> 2N2O(g) Kc =1.2x10^(-35) N2O4(g) --> 2NO2(g) Kc = 4.6x10^(-3) 1/2N2(g) + O2(g) --> NO2(g) Kc= 4.1x10^(-9) Calculate Kc for the reaction between one mole of dinitrogen oxide gas and oxygen gas to give nitrogen tetroxide gas.
  71. Physical science

    1. Nicotine,a poisonous compound found in tobacco leaves,is 74% carbon,8,65% hydrogen and 17,35% nitrogen (a)calculate the empirical formula of nicotine (b)what is the molecular formula of nicotine if it has a molar mass of 165 g.mol^-1
  72. chemistry

    1.0 mol of nitrogen oxide NO and 1.0 mol of oxygen were mixed in a container and heated to 450 oC. At equilibrium the number of moles of oxygen was found to be 0.70 mol. The total pressure in the vessel was 4.0 atm. Calculate the value of Kp for the
  73. chemistry

    You have two SCUBA tanks, one containing air( 80% 20%) and the other containing a nitrox mix that is 60% nigtrogen and 40% oxygen. The volume of each tank is 10.00 L. Determine the number of moles of nitrogen and oxygen in the air tank.
  74. Chemistry

    Trimix 10/50 is a gas mixture that contains 10% oxygen and 50% helium, ant the rest is nitrogen. If a tank of Trimix 10/50 has a total pressure of 2.07 x 10 4 kPa, then what is the partial pressure of helium?
  75. Chemistry

    Calculate the ratio of the effusion rate of oxygen gas (O2) to that of nitrogen gas (N2). Express your answer in decimal form and calculate your answer to at least four sig figs.
  76. Chemistry

    In a 25.8 liter vessel of nitrogen gas that is heated from 10 degrees Celsius to 110 degrees Celsius to reach a final pressure of 17450 mm Hg; how many grams of N2 do you have in the vessel?
  77. Chemistry

    4 L of oxygen at a pressure of 400 Kpa and 1L of nitrogen at 200 Kpa were introduced in to 2 L vessel. (A)What is the total pressure of the gases in the vessel. (B)What is the mole fraction of each gas?
  78. Science

    1.00g of oxygen combine with 0.126 g of hydrogen to form H2O. 1.00 g of nitrogen combie with 0.216 g of hydrogen to form ammonia. Predict the weight of oxygen
  79. AP Chem!

    Hey, I have a test tomorrow in ap chemistry on gases. My teacher said that the test would be many open ended questions that are sort of like "explain what happens when a balloon is lowered into 77degrees C of liquid nitrogen and why" Can you guys give me
  80. Chemistry

    The Solvay process for the manufacture of sodium carbonate begins by passing ammonia and carbon dioxide through a solution of sodium chloride to make sodium bicarbonate and ammonium chloride. The equation for this reaction is H2O + NaCl + NH3 + CO2 →
  81. Chem

    Epsom salts consist of magnesium sulfate heptahydrate. Write its formula. a) How many atoms of oxygen are in 5.15g of Epsom salts? b) How many formula units of the compound are present in 5.15g? c) How many moles of water molecules are in 5.15 g of Epsom
  82. PHY 1

    You hold a hose at 45 degrees to the horizontal and at a height of 1 m from the floor. The water reaches a maximum distance of 10 m from where you are standing. Now you place your thumb over the end of the hose to occlude the opening by 80%, which in turn
  83. Chemistry--Quick Question

    Which of the following are LAWS according to the Scientific Method? It is possible for more than one answer. a. The volume of a gas is inversely proportional to its pressure. b. A solid has a mass of 100.0 grams and a volume of 11.1 mL. c. When a piece of
  84. Science

    you reacted magnesium with a hydrochloric acid aqueous solution and hydrogen gas was produced. Let's say that you collected the gas given off by the reaction and measured it's pressure as 102.1 kPa. If the vapor pressure of water is 16.2 kPa at this
  85. Chemistry

    you reacted magnesium with a hydrochloric acid aqueous solution and hydrogen gas was produced. Let's say that you collected the gas given off by the reaction and measured it's pressure as 102.1 kPa. If the vapor pressure of water is 16.2 kPa at this
  86. chemistry

    a steel cylinder with nitrotgen hydrogen and ammonia gases is at 500C and 5.00 atm if patrtila pressure of nitrogen is 1850 mm Hg and hydrogen is 1150 mm Hg what is the partial pressure of ammonia in mm H</p>
  87. chemistry

    a scuba driver is using eanx32, an enhanced nitrox gas mixture. this mixture contains 32% oxygen with 68% nitrogen. if the cylinder is at a pressure of 250 kpa, what is the partial pressure of oxygen?
  88. chem

    a 200.0ml sample of nitrogen gas N2 is collected at 45.0 Celsius and a pressure of 610 torr what volume in milliliters will the gas occupy at 0.0 Celsius and 760 torr?
  89. Chem

    A sample of an unknown biochemical compound is found to have a percent composition of 55.03 percent carbon, 5.54 percent hydrogen, 32.10 percent nitrogen and the balance oxygen. What is the simplest formula for this compound ? How do I do this?
  90. Science

    If there's 1 gram of nitrogen (N2) at 1 L and 1 gram of hydrogen (H2) at 1 L, would the pressure of H2 be greater than the pressure of N2? And would the density of H2 = the density of N2 at these conditions? There would be more moles of H2 than N2, but the
  91. Physics

    What is the total pressure, in atmospheres, of a 10.0 L container that contains 10 moles of nitrogen gas and 10 moles of oxygen gas at 300 K? I tried using PV=nRT and added both P together but kept getting the wrong answer. n=10, T=300 K, V=1x10^-3 m^3
  92. chemistry

    in a reaction of 3Cu(s)+ 8HNO3(aq)¨ 3Cu(NO3)2(aq) +2NO(g) + 4H2O(l). if 5.58 grams of Cu(no3)2 is made how many grams of nitrogen monoxide is present
  93. Chemistry

    A mixture of gases at 760.0 torr contains 35.0% nitrogen, 22.0% oxygen , and 43.0% carbon dioxide by volume. What is the pressure of the carbon dioxide gas in torr?
  94. Chemistry

    At what pressure would 0.150 mole of nitrogen gas at -23.0oC occupy 8.90 L? -23.o0c = 250 K P=(0.150 mol)(8.31 KPA x L/ K x mol)(250 K) = P is this right?
  95. Statistics

    Assume the body temperature of healthy adults are normally distributed with a mean of 98.2F and a standard deviation of 0.62F. If you have a body temperature of 99.00F, what is your percentile score? Convert 99.00F to a standard score(or a z-score). Is a
  96. chemistry

    the half time of a radioisotope is found to be 4.55 minutes. if the decay follow first order kinetics. what percentage of isotope will remain after 2.00 hours?
  97. Algebra

    Need help with this: 39. Money in a bank account that compounds interest by some percentage acts _____ a. linearly b. exponentially c. negatively d. like a fraction I'm stuck between A or B... Thanks -MC
  98. Math Lit

    A second hand car was put up for sale for R65000.After 2 months it had not sold,and the shop marked it down to R58000. What was the percentage decrease?
  99. Math

    Create a graph from this research In a recent article, the author states that 71% of adults do not use sunscreen. Although 71% is a large percentage, explain why it could be misleading.
  100. Science physics

    The least count of a screw gauge is 0.001cm the diameter of a wire measured by it is 0.225cm. Find out the percentage error in this measurement