1. Chemistry 101

    A volume of 20.0 mL of a 0.140 M HNO3 solution is titrated with 0.850 M KOH. Calculate the volume of KOH required to reach the equivalence point.
  2. Logs

    The number of years n required for an investment at interest rate r to double in value must satisfy (1+r)^n = 2. Using the approximation ln(1+r)=r valid for small r, find the number years n as a function of r.
  3. chemistry

    A volume of 100mL of a 0.800 M HNO3 solution is titrated with 0.640 M KOH. Calculate the volume of KOH required to reach the equivalence point.
  4. physics

    A spherical steel ball bearing has a diameter of 2.540 cm at 23°C. (a) What is the diameter when its temperature is raised to 106°C? (b) What temperature change is required to increase its volume by 0.8%?
  5. physic

    Hi! help me please, Thank you. A spherical steel ball bearing has a diameter of 2.540 cm at 23°C. (a) What is the diameter when its temperature is raised to 94°C? cm (b) What temperature change is required to increase its volume by 0.9%? I only need help
  6. ENGLISH

    Insert articles in the following sentences whenever required: 5 i Scientists are now beginning to worry about contamination of entire solar system. ii People often say that writer’s life is unimportant and all that matters is in books. That is usually
  7. thermodynamics

    if a pump discharges 75 gpm of water whose specific weight is 61.5 lb/ft^3(g=31.95fps^2). find a) the mass flow rate in lb/min, and b) and total time required to fill a vertical cylinder tank 10ft in diameter and 12ft high.
  8. Math

    A tile is in the shape of a parellogram of base 5cm and corresponding height equal to 3cm.Calculate the number of tiles required to cover an area of 45m^2. Plz gve me fst reply nd ful soltn nd ans is 3000tiles
  9. AP Chemistry

    Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO(g) + O2(g) --> 2CO2(g) change in H for this reaction is −135.28 kcal. If 811.7 kcal is released, how many moles of CO must have reacted? 1. 16.3 mol 2. 40.5
  10. ap chemistry

    Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO + O2 yields 2CO2 Delta H for this reaction is -135.28 kcal. If 811.7 kcal is released, how many moles of CO must have reacted? 1). 270.5 mol 2). 40.5 mol 3). 12.0 mol
  11. Physics

    A 64.7 kg astronaut is on a space walk away from the shuttle when her tether line breaks. She is able to throw her 14.1 kg oxygen tank away from the shuttle with a speed of 7.45m/s to propel herself back to the shuttle. Assuming that she starts from rest
  12. Chemistry

    Virtually all the nitric acid manufactured commercially is obtained by the ammonia oxidization process. This involves this first step: Ammonia gas combines with oxygen to form nitrogen monoxide and water vapour. a) Write a balanced equation for the
  13. Biology

    1. Contraction of the diaphragm causes: A. a person to exhale. B. the size of the chest cavity to increase. C. air to flow from the lungs to the outside. D. compression of the lungs. is it B 2. The function of the large intestine is to: A. supply enzymes
  14. CHEMISTRY

    I've been trying to do this problem but I would get confused and stuck.. Consider a sample of a hydrocarbon at 0.959 atm and 298 K. Upon combustion the entire sample in oxygen, you collect a mixture of gaseous carbon dioxide and water vapor at 1.51 atm and
  15. Biology please help

    1. Contraction of the diaphragm causes: A. a person to exhale. B. the size of the chest cavity to increase. C. air to flow from the lungs to the outside. D. compression of the lungs. is it B 2. The function of the large intestine is to: A. supply enzymes
  16. Chemistry

    A reaction between gaseous sulfur dioxide and oxygen gas to produce gaseous sulfur trioxide takes place at 600◦C. At that temperature, the concentration of SO2 is found to be 1.14 mol/L, the concentration of O2 is 1.39 mol/L, and the concentration of
  17. chemistry...weird question

    on heatin, 0.02mol of the element M reacts with 0.025mol of oxygen gas. What is the empirical formula of the oxide of M? The mole ratio is .025/.02=1.25 or 5/4 So the O2 has a ratio of 5 to one Metal. M4 (O2)5= M>sub>4O10 or writing it in lowest
  18. intro to economics

    Please check my answers and I need help on some of the problems. I'm in a intro to economics course at a university. My professor did not provide a book for this course citing that she rarely had her students use it. So all I have are notes. I would like
  19. Chemistry

    1.Calculate the density of oxygen, O2, under each of the following conditions: STP 1.00 atm and 20.0 ∘C 2.To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 4.3-L bulb, then filled it with the gas
  20. chemistry

    At 300.K and 1.00 atm, assume that 25 mL of NO gas reacts with 22 mL of oxygen gas and excess water to produce nitric acid according to the following equation: O (g) H O(l) 2 HNO (g) 2 2NO(g) 3 + 2 + 2 ⎯⎯→ 3 . If all of the nitric acid
  21. Chemistry

    Nitrogen can also be produced from sodium metal and potassium nitrate by the reaction: Na(s) +KNO3 (s) --> K2O(s) +Na2O(s) + N2(g) If we generate oxygen by the thermal decomposition of potassium chlorate: 2KClO3(s) --> 2KCl(s) +3O2(g) How many grams
  22. Chemistry II

    A 12.00 mL sample of sulfuric acid from an automobile battery requires 34.62 mL of 2.42 M sodium hydroxide solution for complete neutralization. What is the molarity of the sulfuric acid? H2SO4 + 2NaOH ==> Na2SO4 + 2H2O molarity NaOH x liters NaOH =
  23. chemistry

    Which of the following statements correctly describes energy levels? A. Electrons can never move to a higher or lower energy level. B. In its outermost energy level, oxygen has 4 valence electrons C. The second energy level holds a maximum of eight
  24. chemistry

    Which of following statements correctly describes energy levels? A. Electrons can never move to a higher or lower energy level. B.In it's outermost energy level, oxygen has 4 valence electrons. C. The second energy level holds a maximum of eight electrons.
  25. chemistry

    which of the following statements correctly describes energy levels? A. Electrons can never move to a higher or lower energy level. B. In its outermost energy level, oxygen has 4 valence electrons C. The Second energy level holds a maximum of eight
  26. Chemistry

    A)What mass of carbon dioxide is produced from the complete combustion of 7.00×10−3 g of methane? B)What mass of oxygen is needed for the complete combustion of 7.00×10−3 g of methane?
  27. Chemistry Ozone layer

    what is the ozone layer made out of because on differnt websites it says different things and i thought it was made out of the three types of oxygen O2 O3 and i don't know the last one but on other things it says differnt please help me
  28. AP Chem - to Dr. Bob

    I don't understand how to even start this problem: A mixture of H2(g), O2(g), and 2 mL of H2O is present in a 0.5 L rigid container at 25 degrees Celsius. The number of moles of H2 and the number of moles of O2 are equal. The total pressure is 1146 mmHg.
  29. math (rate)

    A blue candle is twice as long as a red candle. The blue candle takes 6 hours to burn out, and the red candle takes 15. After 5 hours, what fractional part of each candle is left? The blue candle's length is what fraction of the red candle's length?
  30. Chemistry

    I have know clue how to answer this, but I tried something.(predicting products of electrolysis in aqueous solution)/ Predict the products of the electrolysis of a solution of aqueous MnSO4. I first wrote this: Mn^2+ SO4^2- Then for Mn^2+, it can be
  31. chem

    Combustion reactions involve reacting a substance with oxygen. When compounds containing carbon and hydrogen are combusted, carbon dioxide and water are the products. Using the enthalpies of combustion for C4H4 (-2341 kJ/mol), C4H8 (-2755 kJ/mol), and H2
  32. Chemistry - Stoichiometry/gases

    When 2.38 g of methane burns in oxygen, 119 kJ of heat is produced. What is the enthalpy of combustion (in kJ) per mole of methane under these conditions? Your answer will be in kJ/mol. the Molar Mass of methane is 16.04, so I did 2.38g/16.04=0.14838 mol
  33. Chemistry

    There is a question on my assignment that's asks how many moles of atoms are in x mol of CO2 (and a few others). Let X represent 5x10^-4. How do I do this? Teacher didn't really teach us this. I know in one mol of CO2 there is 2 moles of oxygen atoms, so
  34. physics

    consider system shown in fig. 1. the coeffecient of kinetic friction between block a (m=10 kg) and the table is 0.20. calculate the weight of the hanging block required if this block is to descend at constant speed once it has been set into motion.
  35. physical science

    In raising a 5000-N piano with a pulley system, the movers note that, for every 2m of rope pulled down, the piano rises 0.3m. Ideally, show that the force required to lift the piano is 500-N.
  36. Physics

    A car accelerates uniformly from rest to 21.0 m/s in 6.1 s along a level stretch of road. Ignoring friction, determine the average power required to accelerate the car if the weight of the car is the following. A) 8.0e3N B) 1.2e4N
  37. Business Law

    Consider what this rule might mean to businesses, particularly those that contract with the government. Consider, for example, a store or outlet that purchases federal/military surplus. What provisions might they need to include in a contract that might
  38. physics(capacitors)

    A sheet of paper 40mm wide and (1.5 x 10^-2) thick is placed between a metal foil of the same width is used to make a 2.0 UF capacitor. If the dielctric constant(relative permitivity of the paper is 2.5 ,what length of paper is required?
  39. Chemistry

    Help with lab report Need Help finishing my lab report.KNOWN VALUES ARE V OF HCL=50ML,M=2.188.V OF NAOH=55.3ML,M=2.088.INTIAL TEMP FOR HCL=22.5C,NAOH IS 23C.this is for part A: Mass of final NACL solution assuming that the density of a 1 M Nacl solution is
  40. Chemistry

    Water is exposed to infrared radiation of wavelength 3.0×10^−4 cm. Assume that all the radiation is absorbed and converted to heat. How many photons will be required to raise the temperature of 1.7 g of water by 2.2 K?
  41. physics

    an originally stationary car with a mass of 1500 kg reaches a velocity of 15 m/sec 5 sec after starting. what is the cars acceleration? how much force was required to reach this acceleration?
  42. Personal Project :)

    Hey I'm Kaela, 9th grade and we're required to do a mini personal project. I can't decide on what to do :/ Anyone help? I'm interested with models, runways, model photo shoots, etc etc. :)
  43. Math

    determine the force required in A and B in the figure on the worksheet to hold steady the 100 kg load pictured. Hint: The vertical components of A and B combined will hold the load
  44. organic chemistry

    How many milliliters of boiling water are required to dissolve 25 g of phthalic acid? If the solution were cooled to 14 degree Cellucius, how many grams of phthalic acid would recrystallize out?
  45. Physics

    A skier of mass 74.5 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 55 m up a 31° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
  46. physics

    true or false . refraction always involves a change in the speed and direction of a wave wat is required in order for diffraction to occur? wat causes wave interference?
  47. physics

    The speed of a transverse wave on a string is 457 m/s, while the wavelength is 0.228 m. The amplitude of the wave is 2.05 mm. How much time is required for a particle of the string to move through a total distance of 1.34 km?
  48. geometry

    The sides and bottom of a swimming pool are to be lined with vinyl to prevent it from leaking.The pool measures 6m by 4m, and has a uniform depth of 2m. Calculate the area of vinyl that will be required.
  49. physics

    A skier of mass 75.0 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 60.0 m up a 35° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
  50. Chemistry

    Why is heating required for this formation: 6NaOH (aq) + Al2(SO4)3 (aq) ¨ 2Al(OH)3 (s) + 3Na2SO4 (aq)? Wouldn't freezing favour the formation of Al(OH)3 since freezing lower the KSP and more Al(OH)3 would precipitate?
  51. physics

    At what speed should a space probe be fired from the earth if it is required to still be traveling at a speed of 3.48 km/s, even after coasting to an exceedingly great distance from the planet (a distance that is essentially infinite)?
  52. physics

    A jumbo jet needs to reach a speed of 369 km/hr on the runway for takeoff. Assuming a constant acceleration and a runway 1.6 km long, what minimum acceleration from rest is required?
  53. dav science

    a machine gun fires 25 g bullets at the rate of 600 bullets per minute with a speed of 200 m/s. calculate the force required to keep the gun in position.
  54. Chem ? Help!

    What is the answer and how do I Calculate the quantity of energy required to change 3.00 mol of liquid water to steam at 100°C. The molar heat of vaporization of water is 40.6 kJ/mol.
  55. ap physics

    A skier of mass 70.5 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 60 m up a 38° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
  56. physics

    A hydraulic jack is used to move an 8896 Newton car. If the area of the output piston is 8 times that of the input piston, how much force is required to lift the car?
  57. Science

    In 400min,2.4grams of copper is obtained by Cu2+ solution,find how many Amphere is required for this experiment. Using the same current and time what mass of Cu2+ will be obtained from a Cu(NO3)2.
  58. physics

    A motorcycle stunt rider must jump a 100m wide canyon given a 20° ramp positioned on either side. What minimum speed is required so the rider will clear the canyon?
  59. Finance

    You have arranged for a loan on your new car that will require the first payment today. The loan is for $32,000, and the monthly payments are $620. Required: If the loan will be paid off over the next 60 months, what is the APR of the loan?
  60. chemistry

    the abbreviated structure formula of the products of the complete hydrolysis of tocainde is required together with any new functional groups formed. I am somewhat stuck and have got only as far as identifying the functional groups in tocaine. please can
  61. Calculus

    A tank in the shape of a right circular cylinder is filled with water (62.5 lb/ft3). It has a height of 8 ft and a diameter of 10 ft. How much work is required to pump all the water to a spout that is 3 ft above the top of the tank?
  62. calculus

    A tank in the shape of a right circular cylinder is filled with water (62.5 lb/ft3). It has a height of 8 ft and a diameter of 10 ft. How much work is required to pump all the water to a spout that is 3 ft above the top of the tank?
  63. Calculus

    A tank in the shape of a right circular cylinder is filled with water (62.5 lb/ft3). It has a height of 8 ft and a diameter of 10 ft. How much work is required to pump all the water to a spout that is 3 ft above the top of the tank?
  64. Chemestry

    What volume of 0.140 M K2Cr2O7 will be required to oxidize the Fe2+ ion in 81.5 mL of 0.176 M FeSO4 solution? Cr2O72- + Fe2+ Cr3+ + Fe3+ (acid solution)
  65. math

    Eric Rose wants to buy a Ford Explorer that costs $26,000 with an interest charge of $3,000. If there are 50 equal payments required, what will Eric's monthly payment be?
  66. Physics

    A skier of mass 73.5 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 58 m up a 32° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
  67. Physics

    This is a pretty simple physics problem, but I do not know how to go about it. How do I: Show that the time required for a projectile to reach its highest point is equal to the time for it to return to its original height?
  68. Chemistry

    When a 5.00 ml sample of vinegar is titrated, 44.5 ml of 0.100 m NAOH solution is required to reach the end point. What i sthe concentration of vinegar in moles per liter of solution?
  69. Maths,physics,biology,english,arabic,chemistry

    Calculate the mass of NaOH required to make 500ml of 0.5 M aqueous solution (Molecular mass of NaOH=40)
  70. physics

    A skier of mass 65.0 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 57.0 m up a 35° slope (assumed to be frictionless) at a constant speed of 2.0 m/s? J
  71. pysics

    The quantity of heat required to raise the temperature of 500g of copper from 16oc +116oc assuming the specific heat capacity of copper =400j /kgk
  72. Science

    Calculate the amount of heat required to completely sublime 63.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 C.
  73. Chemistry

    How many kilojoules of heat are required to melt a 10.0 g popsicle at 0 degress C? Assume the popsicle has the same molar mass and heat of fusion as water. Could someone tell me what equation to use to solve this or the steps? Thank You.
  74. Calculus (Definite Integrals)

    How many definite integrals would be required to represent the area of the region enclosed by the curves y=(cos^2(x))(sin(x)) and y=0.03x^2, assuming you could not use the absolute value function? a.) 1 b.) 2 c.) 3 d.) 4 e.) 5
  75. Calculus

    A box with a square base and no top is to be built with a volume of 6912 in^3. Find the dimensions of the box that requires the least amount of material. How much material is required at the minimum?
  76. Chemistry

    If 920 mL of 0.0402 M aqueous LiOH reacts stoichiometrically according to the balanced equation, what mass (g) of gaseous CO2 is required? 2 LiOH(aq) + CO2(g) → Li2CO3(aq)
  77. Physics

    A skier of mass 67.0 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 59 m up a 32° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
  78. physics

    marco pushes a stalled car 20 meters with a constant force of 500N in 50 seconds. Calculate the average power marco required to move the car.
  79. math

    one lady borrowed sh. 100,000. If she is required to pay an interest of 5% of the borrowed cash every month, how much money will she pay after fove months? #please people help me this question#
  80. Math

    a rectaguler tub with dimesions 2m x 1m x 0.5 is filled with water using a pail of radius 0.1m and height 0.35. How many pails of water will be required? give yor answer to the nearest pail.
  81. Science

    Calculate the amount of heat required to completely sublime 63.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 C.
  82. HIPPA Law

    At what point during the course of treatment of a new pt should the notice and disclosure of health info ,required under HIPPA be given and why ? Please check my answer. I think that it should happen before treatment begins. does anyone else agree or have
  83. chemistry

    If 0.1200g of sodium carbonate is dissolved in 50 mL of water and titrated with 0.1000 M HCl, how many mL of HCl will be required to reach the second endpoint? CO3^-2 + H^+1 --> HCO3^-1 HCO3^-1,+ H^+1 --> H2CO3
  84. Chem1412

    The melting point of benzene (C6H6) is 5.5 oC and the heat of fusion at that temperature is 9.87 kJ/mol. How much heat would be required to melt 35.0 g of benzene at 5.5 oC? Atomic weights: C 12.011 H 1.00794
  85. applied physics

    the work required to lift eleven 94.0lb bags of cement from the ground to the back of a truck is 4340ft lb. what is the distance from the ground to the bed of the truck?
  86. AP Chemistry

    What volume of 0.149 M K3PO4 is required to react with 41 mL of 0.793 M MgCl2 according to the equation 2 K3PO4 + 3 MgCl2 → Mg3(PO4)2 + 6 KCl Answer in units of m
  87. Financial Investments

    The number of years n required for an investment at interest rate r to double in value must satisfy (1+r)^n = 2. Using the approximation ln(1+r)=r valid for small r, find the number years n as a function of r.
  88. physics

    A mouse is running away from a cat at. 75 m/s and, at 1.25 m from his mouse hole, he accelerates at a constant rate of. 25 m/s^2 until he reaches his hole safely. How long a time was required for him to cover te last 1.25m?
  89. AP Physics 1

    How much work is required to compress a spring, k = 33.3 N/m, from its equilibrium point at x = 0.0 m to x = 5.0 m? I am not sure how to approach a problem like this - what equation do I use? I know work = Force * Distance, but these aren't exactly terms I
  90. Chemistry(Please help, thank you!!)

    Determine the concentration of a NaOH solution if 27.80mL of NaOH is required to neutralize 10.00mL of a 1.00 M H2SO4 solution. (Hint:Review monoprotic vs. diprotic acids.) would I do (27.80)(10)? Thank you for your help!!
  91. Physics

    In the javelin throw at a track-and-field event, the javelin is launched at a speed of 33.0 m/s at an angle of 36.5° above the horizontal. How much time is required for it to hit the target that is the same height across the field?
  92. physics

    A mouse is running away from a cat at. 75 m/s and, at 1.25 m from his mouse hole, he accelerates at a constant rate of. 25 m/s^2 until he reaches his hole safely. How long a time was required for him to cover te last 1.25m?
  93. science

    A truck with a mass of 20t has a tractive resistance of 280N/t if the truck travels at a speed 72km/h. Calculate the following. a) The distance 36s. b) The power required for the speed.
  94. difficult chemistry

    Calculate the molarity of thiosulfate solution if 0.400mg of Kl03 required 100ml of the thiosulfate solution provided that excess kl and hcl were added. Who helps me
  95. Finance

    How do you determine the value of a 1,000 bond with a 7 percent coupon rate maturing in 20 tears for an investor whose required rate of return is 8 percent? Please show formula and result
  96. chem101

    if 23.74ml of 0.01470M NaOH are required to completely neutralize 25.00ml of gastric juice,calculate the concentration of the hydrochloric acid[in g/L]in stomach gastric juice
  97. Chemistry

    What mass of lithium (in g) is required to react completely with 57.5mL of N2 gas at STP? Lithium reacts with nitrogen gas according to the following reaction: 6Li(s)+N2(g)→2Li3N(s)
  98. Phyics

    A pool ball leaves a 0.75-meter high table with an initial horizontal velocity of 30 m/s. Predict the time required for the pool ball to fall to the ground.
  99. Biology

    how many mL of concentrated (15 M) hydrochloric acid (HCL) are required to prepare 500 mL of 6 M hydrochloric acid?
  100. Chemistry

    How many mL of a stock 2.50M HCl solution are required to prepare 25.0 mL of a 0.15M HCl solution?