1. organic chemistry

    chloroform is an excellent solvent for extraction caffeine from water. Kd = 10 for caffeine in chloroform- water at 25 Celsius. what weight of caffeine would be removed from a solution of 4g caffeine in 100ml water by a single extraction of 100 ml of
  2. Math

    A glass is filled with water and the total weight is 220g. If the glass is halffilled with water, the total weight is 120g. What is the net weight of the glass? There may be a logic way of doing it but the following is the longer "math" way. G = weight of
  3. General Chemistry

    A cylinder with a movable piston contains 2.00g of helium,He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the
  4. Calculus HARD NEED HELP

    The volume of a cone of radius r and height h is given by V=(1/3)pir^2h. If the radius and the height both increase at a constant rate of 2cm/s at which rate in cubic cm/s is the volume increasing when the height is 8cm and the radius is 6cm. So The answer
  5. physics

    One cubic centimetre (1.0 cm3) of water has a mass of 1.0 × 10−3 kg. (a) Determine the mass of 1.0 litre of water. Assuming that biological substances are 98% water, estimate the masses of (b) a cell with a diameter of 1.0 μm, (c) a human
  6. OChem

    Suppose a student obtained a 0.15g of cruse salicylic acid. How much water would be needed to just dissolve it at 75 degrees Celsius? How much salicylic acid would remain dissolved in that amount of water at just 10 degrees Celsius? What percent of the
  7. history

    Describe Gouverneur Morris's early childhood uprising? "uprising"??? Do you mean "upbringing"? Please note that we don't do students' homework for them. Our tutors try to give you the information to help you complete your assignment on your own. If there's
  8. Thermodynamics

    Design Problem- A steam boiler may be thought of as a heat exchanger. The combustion gases may be modeled as a streram of air because their thermodynamic properties are close to those of air. Using this model, consider a boiler that is to convert saturated
  9. Thermodynamics

    Design Problem- A steam boiler may be thought of as a heat exchanger. The combustion gases may be modeled as a streram of air because their thermodynamic properties are close to those of air. Using this model, consider a boiler that is to convert saturated
  10. Geometry

    An architect is designing a public storage building with 2 different sized storage units the ceilings are 8 feet high in each storage unit a. All storage units have square floors the volume will be 1800 what are the dimensions of each small unit b. The
  11. science

    Calculating A sample of barium nitrate is placed into a jar containing water. The mass of the barium nitrate sample is 27 g. Assume the water is at 20 ºC and that the resulting barium nitrate solution is saturated. What mass of water is present in the
  12. chemistry

    in a particular experiment, 150.0 g of ammonium chloride were reacted with 290.0 g of barium hydroxide octahydrate, producing 157.2 g of water 1. find the limiting reagent in this situation 2. calculate the theoretical yield of water 3. calculate the
  13. Chemestry

    A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume
  14. CHEM

    A cylinder with a movable piston contains 2.00 of helium, , at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume
  15. 7th Grade Math

    A pentagonal prism has dimensions that are four times the dimensions of a similar pentagonal prism. So its volume is _____times the volume of the smaller prism. A) 64 B) 8 C)16 D)4 Would it be A) 64? Next Question: If the dimensions of a cylinder are
  16. chemistry

    A cylinder with a movable piston contains 2.00 g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the
  17. Physics

    a modified U-tube: the right arm is shorter than the left arm. The open end of the right arm is height d = 10.0 cm above the laboratory bench. The radius throughout the tube is 1.60 cm. Water is gradually poured into the open end of the left arm until the
  18. physics

    a modified U-tube: the right arm is shorter than the left arm. The open end of the right arm is height d = 10.0 cm above the laboratory bench. The radius throughout the tube is 1.60 cm. Water is gradually poured into the open end of the left arm until the
  19. chemistry

    Long but quick chemistry lab that I need confirmation on answers? OK so I have this lab that went pretty quick and smooth and I have an online assessment that I needed to put all my figures in. I am all complete but am still having trouble with 1 problems
  20. Information Literacy

    1-To determine the best place to begin your online research, you should first A. identify keywords and search terms. B. formulate your research question. C. choose several verbs and modifiers to help define your search. D. settle on a single, concise
  21. analaytical chemistry

    a student mixes equal volume of 1 molar tin chloride and coper sulfate and observe tha no preciptate forms .then the students mxis equal volume of 1molar solution of zinc sulfate and tin floride and observe the formation of precipitate .which compound is
  22. physics!

    The mass of an automobile is 1160kg, and the distance between its front and rear axles is 2.54m. The center of gravity of the car is between the front and rear tires, and the horizontal distance between the center of gravity and the front axle is 1.02m.
  23. Math

    Mix A=2 cups concentrate:3 cups water Mix B=5 cups concentrate:9 cups water Mix C=1 cups concentrate:2 cups water Mix D=3 cups concentrate:5 cups water For each mix, how much concentrate and how much water are needed to make 1 cup of juice?
  24. geometry

    if a polygon has a volume of 19 cm and is dilated by a factor 3\2 , what will be the volume of the dilated polygon
  25. HELP!!! Math

    The volume of a pyramid varies jointly as its height and the area of its base. A pyramid with a height of 12 feet and a base with area of 23 square feet has a volume of 92 cubic feet. Find the volume of a pyramid with a height of 17 and a base with an area
  26. Chemistry

    If air has an average density of 1.29 g/l and Co is reported at 2.0 ppm, what volume of air will contain 1.00 mole of Co? There will have to be 1/(2*10^-6) = 500,000 times as much mass of air as CO. The mass of the CO is 28.0 g (1.00 mole), so that
  27. Chemistry

    A balloon containing 0.600 mole of SO2 gas has a volume of 275 mL at a certain temperature and pressure. What volume, in milliliters, would a 0.765 mole sample of SO2 gas occupy at the same temperature and pressure conditions?
  28. Chem Oxidation-Reduction Titrations

    In our lab, the data consists of 1. Volume of NaOCl (mL): Trial 1= 10 ml & Trial 2= 10 mL. How can we find the concentration (Molarity), what would the calculated value be? 2. Volume of H2O2 (mL): Trial 1= 1/ml & Trial 2= 1/mL. How can we find the given
  29. volume

    Jasmine is a manufacturing engineer who is trying to find out if she can use a 20-inch-by-12 inch sheet of cardboard and a 15-inch-by-16-inch sheet of cardboard to make boxes with the same height and volume. Is such a pair of boxes possible? Please give
  30. Geometry

    The radius of Jupiter is approximately 44,423 miles, and the radius of the Earth is approximately 3,960 miles. How many times larger is the volume of Jupiter than the volume of the Earth? Round your answer to the nearest whole number.
  31. 8th grade

    2 cylinders are proportional the smaller cylinder has a radius of 4 centimeters, which is half as large as the radius of the larger cylinder. the volume of smaller cylinder =250 cubic cemtimeters. what is the volume of the larger cylinder?
  32. Chemistry

    One difference between gases and liquids is that: (A) a gas may consist of both elements and compounds (B) a gas assumes the volume of its container (C) a gas is made up of molecules (D) all of the above are correct Is the correct answer, (B), a gas
  33. Chemistry

    Molar volume of an ideal gas at S.A.T.P. (25oC and 1.00 bar is 24.8 dm3 mol-1. Assume that gases are at 225oC and P=1.00 atmosphere before and after the combustion and behave as ideal gases. The chemical equation for the combustion of butane is: 2C4H10(g)
  34. Math

    the stopping distance of an automobile is directly proportional to the square of its speed v. a car required 90 feet to stop when its speed was 70 miles per hour. find a mathematical model that gives the stopping distance d in terms of its speed v. D=
  35. SCIENCE Please help

    A cloud forms around 45° south latitude and is carried through the atmosphere on the Westerlies. As the water molecules in the cloud move through the atmosphere, which step in the water cycle is most likely to happen next? The molecules cool and
  36. chm

    calculate the van dar waals coorectionj terms to pressure and volume for Cl2 at STP. The values of the van der waals constant a and b are 6.49L2-atm/mol2 and 0.056L/mol, respectively, for Cl2. At STP, which is the major cause of deviation from ideal
  37. Chemistry

    A 67gr mass of solid iron is heated by a flame until the temp of the iron equals the temp of the flame. The solid iron is then dropped into 250gr of liquid water at 26 degrees C. After 5 mins, the iron and the water are both at 47 degrees C. Specific heat:
  38. physics

    An insulated Thermos contains 140 cm3 of hot coffee at 89.0°C. You put in a 11.0 g ice cube at its melting point to cool the coffee. By how many degrees (in Celsius) has your coffee cooled once the ice has melted and equilibrium is reached? Treat the
  39. physics

    An insulated Thermos contains 140 cm3 of hot coffee at 89.0°C. You put in a 11.0 g ice cube at its melting point to cool the coffee. By how many degrees (in Celsius) has your coffee cooled once the ice has melted and equilibrium is reached? Treat the
  40. Physics

    5) An insulated Thermos contains 190 cm3 of hot coffee at 79.0°C. You put in a 11.0 g ice cube at its melting point to cool the coffee. By how many degrees (in Celsius) has your coffee cooled once the ice has melted and equilibrium is reached? Treat the
  41. 11th Grade Physics

    An aircraft has a take-off speed 180km/h and has length 250m from the start just before take-off a serious snag is detected in the engine and the aircraft failed to take-off. There is a wall at a distance 'd' = 230m ahead of the take-off point. The pilot
  42. Chemistry

    Which of the following systems would be considered to be at equilibrium: I. an open flask with 2.0 mL of perfume II. a closed flask with 10 mL of water III. an open flask with 10 mL of water IV. a closed flask with an ice cube and 10 mL of water a. I d. b.
  43. English: Please help

    18. What is one disadvantage of accessing the Internet through a public search engine such as or ? A.) It’s open to anyone, so the information comes from many different people. B.) You won’t be able to access documents that have not been published
  44. math 1 question pls help!!!!!

    7. A rectangular prism has a width of 92 ft and a volume of 240 ft3. Find the volume of a similar prism with a width of 46 ft. Round to the nearest tenth, if necessary. (1 point) 30 ft3 40 ft3 60 ft3 120 ft3*** this one was tricky pls help asap!!! thanx in
  45. Chemistry

    Jack occasionally goes to work by bicycle where he exhales once per 3.00 sec. If in Jack’s every exhale is 4.50% CO2 (by volume), he exhales a total volume of 4.6 L each time, and it takes Jack 20.0 minutes to bike to work, how many grams of CO2 has he
  46. Physics

    The rolling resistance for steel on steel is quite low; the coefficient of rolling friction is typically μr=0.002. Suppose a 180,000 kg locomotive is rolling at 19 m/s on level rails. A) If the engineer disengages the engine, how much time will it take
  47. Math

    Please Help! The number of cars sold weekly by a new automobile dealership grows according to a linear growth model. The first week the dealership sold five cars (P0=5 ). The second week the dealership sold cars (P1=12 Pn = Pn−1+7 12-5=7 Pn=5+7n If this
  48. now mr. damon, physics

    A 63.8 kg block of silver is at initially at 107 C. 1.0 kg of ice at its freezing point is placed onto the block to cool it. As the ice melts, the water is free to flow off (so that the water never increases in temperature). After all the ice melts, what
  49. Is anyone here a chemistry genuis?

    The formate ion, (CHO2-), is related to the acetate ion and forms ionic salts with many metal ions. Assume that 9.7416 g of M(CHO2)2 (where M represents the atomic symbol for a particular metal) are dissolved in water. When a solution of 0.200 M sodium
  50. chem

    a 45.8mL sample of a 5.8 M KNO3 solution is diluted to 1.00L. What volume of the diluted solution contains 15.0g KNO3? how do you do this? moles of solution: 5.8*.0458 moles Grams of solute= moles*molmassKNO3 Volume of 15g= 1000ml*15/gramssoluteabove
  51. Science

      17. You need to conduct an experiment in the laboratory. This requires that you prepare 500 ml of  sodium acetate buffer with pH = 4.30. In laboratory you have  solution of CH3COOH (pKa = 4.75), and a stock of CH3COONa.3H2O (MW=136.082 g/mol). Using
  52. Chemistry

    Why are smaller alcohols fully miscible with water while larger alcohols have lower solubility in water? A)In larger alcohols, the polar hydrocarbon chain cannot interact with non-polar water molecules and limits alcohol's ability to interact with water.
  53. Chemistry

    Why are smaller alcohols fully miscible with water while larger alcohols have lower solubility in water? A. In larger alcohols, the polar hydrocarbon chain cannot interact with polar water molecules and limits alcohol's ability to interact with water. B.
  54. physics

    Water waves in a lake travel 5.23 m in 1.52 s. The period of oscillation is 0.84 s. What is the speed of the water waves? Answer in units of m/s. what is the wavelength?
  55. science help

    Which of these questions can be answered through science? What is the best water sport? Why should we value honesty? Why does water change into steam? What is the most important thing in life? is it c
  56. chemistry

    The 17.35 g of NaCl sample was dissolv ed in an unknown amount of water. All we know is that prepared solution has 22.5% of NaCl . The mass of water is _____ g.
  57. science

    an object was placed into a container of water. the arrow shows that thermal energy is flowing from the water to the object. what is a valid conclusion
  58. Physics

    If you want to heat 100 kg of water at 20 ° C for your bath, calculate the amount of heat in the water. Then it shows that this is equivalent to 8360 kilojoules.
  59. Algebra

    Pure water is being added to a 25% solution of 120 milliliters of hydrochloric acid. How much water should be added to reduce it to a 15% mixture ?
  60. chemistry

    If 1.20 grams of sodium metal are reacted with 4.00mL of water, how many grams of NaOH will be produced (density of water= 1.00g/mL)
  61. math

    the building supply store sells one liter bottles of water for $1.09 approximately how many 8 ounce servings of water in 1 liter
  62. chemistry

    when it absorbed energy from a 79.4 g sample of water whose initial temperature was 70.1 °C. What is the specific heat of the metal in J/g·°C? How do i get the final temperature of water
  63. science

    Water is useful for reducing friction between objects. However you also learned that (due to friction) moving water causes rough rocks to become smooth. How can this be?
  64. Chemistry

    If all of the energy from a 60-watt bulb was put into 1 gram of water at room temperature for 2 seconds, how much would the temperature of the water increase?
  65. Maths

    Water from a tap flows into a bath at a rate of 750ml/s. How long does it take to fill a bath with 180 litre of water?
  66. math

    A tank is full in 60 min with water.If amount of water is doble in 1min then in what time the half tank is fill.
  67. math

    a cylindrical tank with diameter 2.0m and height 3.2m is to be filled with water. how many litres of water are needed to fill the tank? 100cm3 = 1L
  68. Math

    These review questions are stumping me. How much water must be added to 50 ML of a 35% acid solution to produce a mixture that is 20% acid. Could it be as simple as 15% water?
  69. chemistry

    a 100g sample of wate at 90oC is added to a 500g sample of water at 10oC. what is the final temperature of the water
  70. science

    The solubility of NaCl in water at 100 degrees celsius is 39.1 g/100 g water. Calculate the boiling point of this solution?
  71. Chemistry

    If all of the energy from a 60-watt bulb was put into 1 gram of water at room temperature for 2 seconds, how much would the temperature of the water increase?
  72. chemistry

    dissolving 4.022 g of a salt in 100 mL of water changes temperature by -1.2^oC: what is the heat absorbed? The specific heat of water is 4.184 J/(g*C)
  73. john tyler

    a 751 diver drops from a board 9.10 m above the water's surface. How much kinetic energy does the diver have right before he hits the water?
  74. Math palette of problems

    If 2/9 gallon of water fills a bucket 3/5 full, how many gallons of water are needed to fill the bucket?
  75. chemistry

    How much ice (in grams) would have to melt to lower the temperature of 355mL of water from 26∘C to 6∘C? (Assume the density of water is 1.0 g/mL.)
  76. Physics

    Please show each step: Consider a mixture of 100 grams of water at 25 ° C with 75 grams of water at 40 ° C. Calculate the final temperature of the sample.
  77. Chemistry

    12.00 g of sugar is dissolved in some water in a cylinder of diameter 7.00 cm. To what height should the cylinder be filled (with more water) to produce a solution with concentration 11.00 g/dm^3?
  78. college

    a 200 L electric water heater uses 15 kW of electric power. If the herter is 90% efficient, how long does it take to heat the water in the tank from 16 C to 61 C?
  79. physics

    A fountain sends water to a height of 149 m. What is the difference between the pressure of the water just before it is released upward and the atmospheric pressure?
  80. Science

    A cicular pool with a radius oF 12 meter if filled with water to a depth of 3 meters. What is the weight of water in the swimming pool?
  81. physics

    a stone is dropped down a well if it takes 5s to reach the surface of the water calculate how deep the well is , what is the velocity when it reaches the surface of the water
  82. physics (easy)

    Will a 7.25 kg ball with a diamter of 22 cm float in water? I know that the radius is 11 cm and that the density of water is 1000kg/m^3 and I got that it will float but it just doesn't sound right. Could anyone help please?
  83. Geography

    What happens to temperature and precipitation as one moves inland and away from water bodies? I know that land heats and cools faster than water bodies.
  84. physics

    Water with a mass of 0.500 kg at 15.0 degree C is mixed with 0.800 kg of water at 35.0 degree C. What is the final temperature T_f of the mixture?
  85. Physics

    If an oil tank that if 15ft tall which is holding oil and water, the water being 8 ft, how much pressure will have when I is opened and begins to flow?
  86. Physics

    A water tank is20m deep if the water barometer reads10m at that place then what is the pressure at the bottom of the tank in atmosphere
  87. Chemistry

    what occurs when sugar is added to water.... It dissolves? the freezing point of the water will decrease and the boiling point will increase Thanks for your help i think i get it better now That't right.
  88. Chemistry

    How much heat in kJ is required to melt 54 grams of ice at 0 degrees C into water at 0 degrees C if delta Hvap for water = 6.01 kJ/mol?
  89. Math

    Hi! You need 2 cups of water, but you only have a liquid measuring cup that measures up to 3 pints. what can you do to get the 2 cups of water that you need? explain and show your work.
  90. Math

    The amount of water,V cm3 , in a leaking tank at time t seconds is given by V = (15-t)^3 for 0<=t<=15 Find the rate at which the water leaves the tank when t = 4.
  91. Physics/Chemistry

    1 L of 20 degrees C water is mixed with 4 L of 40 degrees celcius water. What will be the temp of this mixture? the only thing i know is like V/T = V/T but im not sure how it relates to this problem, if at all.
  92. Physics

    What would the gauge pressure be on a diver in atmospheres if she could dive to a depth of one km in sea water? One atmosphere is 1.01 X 10^5 N/m2. The density of sea water is 1.03 X 10^3 kg/m3.
  93. Algebra

    A tank contains 1200 litres . A tap is turned on and 40 litres of water escape each minute. How much water has escaped in 12 minutes.
  94. physics

    A diver achieves a horizontal velocity of 3.76 m/s from a diving platform located 6m above the water. How far from the edge will the diver be when she hits the water?
  95. physics

    A person is standing at the edge of the water and looking out at the ocean. The height of the person's eyes above the water is h = 1.6m. and the radius of the earth is R = 6.38 X 10^6 m. (a) How far is it to the horizon?
  96. Math

    Hank's fish bowl holds 9/10 gallon of water. It is now 2/3 full. How much water is in the bowl? I subtracted and my answer is 7/30. Is this correct?
  97. chemistry

    calculate the freezing point of an aqueous solution containing 10.50 g of MgBr2 in 200 g of water (MgBr2=184 g, Kf for water =1.80 K kg mol-1)
  98. Math

    write an inequality representing the temperature t of the ocean water during the formation of the hurricane if the ocean water is above 80 degrees farenheit
  99. physics

    Water is lifted out of a well 38.0m deep by a motor rated at 1.00hp. assuming70% efficiency, how many kilograms of water can be lifted in 1 min?
  100. Chemistry

    The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?