osmotic pressure chemistry

10,949 results, page 37
  1. Physics

    Suppose a distant world with surface gravity of 7.12 m/s2 has an atmospheric pressure of 7.48 104 Pa at the surface. (a) What force is exerted by the atmosphere on a disk-shaped region 2.00 m in radius at the surface of a methane ocean?________N (b) What
  2. Chemistry

    Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -247 B -375 C 191 D -483 Express your answer to three significant figures and include the appropriate units. My answer was 285 kJ/mol
  3. Chemistry

    Balance the equation: NO2- (aq) + Al (s) --> NH3 (g) + AlO2- (aq) (basic solution) ** please note the "2-" on the NO2- and AlO2- are not subscripts, they are the charges. I missed a few classes in Chemistry and find myself lost. I have tried to learn these
  4. chemistry

    I did a chemistry lab on polarimetry where we separated two enantiomers into individual salts and then used a polarimeter to determine the specific rotation and optical purity. What is the relationship of the proline salts to one another? i said that being
  5. Physics

    A./_\ B.\_/ C.|_| The three tanks shown above are filled with water to an equal depth. All the tanks have an equal height. Tank A has the greatest surface area at the bottom, tank B the least and tank C the middle. (Select T-True, F-False, G-Greater than,
  6. Physics

    High-heeled shoes can cause tremendous pressure to be applied to the floor. Suppose the radius of a heel is 6.00 10-3 m. At times during a normal walking motion, nearly the entire body weight acts perpendicular to the surface of such a heel. Find the
  7. Chemistry

    If I was designing an experiment where hydrogen gas was collected over a 0.1 M aqueous HCl solution from the reaction with zinc metal and I assume complete, rapid reaction, what mass of zinc would be used to collect between 50 and 100 mL of the gas? Note:
  8. Math

    In a class 85% of the student received the highest grade in English Literature, 80% in Math, 75% in History, and 30% in Chemistry. About what percentage of the students could you say for sure that they received the highest grade in all 4 subjects?
  9. Chem 3A

    please help me with this chemistry problem. 1) Write out a balanced chemical reaction equation for the reaction of magnesium with hydrochloric acid, and then What is the Theoretical Yield after balancing the chemical equation?
  10. Chemistry 2

    36.) Suppose a chemistry student discoveres that a block of pure ice is left on her porch as she goes to school one day. What will be the percent composition of the pure ice block?
  11. lighthouses

    Hi my son has to do a lighthouse for a school project and it has to really light, I'm not really sure how to go about this project or what materials he will need. Can anyone offer any help Believe it or not here is a site on how to build a model
  12. Chemistry

    A 19th-century chemist, Marcellin Berthelot, suggested that all chemical processes that proceed spontaneously are exothermic. True or False? I thought it was true, but then in my chemistry textbook, I could not find this person's name. Can someone verify
  13. Chemistry

    You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 6 dollars/hr , and each shift lasts 75minutes . Your laundry requires 6quarters/load. How many shifts must you work if you wish to wash 10 loads of laundry?
  14. Chemistry

    Chemistry question: Given: CH4 + 2O2 ~ CO2 + 2H2O C - H = 99 kcal O - O = 119 kcal C = O = 192 kcal O - H = 111 kcal Calculate the change in energy for the CH4 - O2 system.
  15. Organic Chemistry

    Hello, I'm studying Organic Chemistry in College and in a homework there was an exercise that I could't resolve about aldol condensation of the same molecule. It was like this: What are the possible products of the aldol condensation of 4 molecules of
  16. Biology

    Is there any biology websites for teens??? (NOT games! notes and quizzes to practice). The Science of Biology The Chemistry of Life Cell Structure and Function Photosynthesis & Respiration Something REALLY easy to understand(btw I'm going to the 9TH
  17. Chemistry

    The oxides of Group 2A metals (symbolized by M here) react with carbon dioxide according to the following reaction: MO(s) + CO2(g)  MCO3(s) A 2.85-g sample containing only MgO and CuO is placed in a 3.00-L container. The container is filled with CO2
  18. chemistry

    Can someone please help me with some steps towards solving this problem? A glass tumbler containing 243.3cubic centimeters of air at 1.00e2kPa (barometric pressure) and 20Celsius is turned upsde down and immerse in a body of water to a depth o 20.5m. The
  19. Chemistry.

    Ca(HCO3)2(s) decomposes at elevated temperatures according to the stoichiometric equation Ca(HCO3)2(s)-> CaCO3(s) + H2O(g) + CO2(g) a.) If pure Ca(HCO3)2(s) is put into a sealed vessel, the air is pumped out, and the vessel and its contents are heated, the
  20. science

    A bicycle tire is filled with air pressure of 6 atm at a temperature 20 Degrees Celsius. Riding the bicycle on asphalt on a hot day at a temperature 42 degrees Celsius makes the volume of the tire increase by 2%. What is the new pressure in the bicycle
  21. chemistry

    for the vaporization of water at 1.00 atm, delta H=43.54 kj/mol at 298 K and delta H= 40.68 kj/mol at 373 K. the constant-pressure heat capacity of liquid water is 75.3 J/molK. calculate the constant pressure heat capacity for H2O(g).
  22. chemistry

    I wonder how to calculate the Kp if the question gives us the total pressure and no of mol of reactant. Without giving the mol of product how can i calculate the Kp. Can anybody help me what to do to calculate the Kp. Here is the question im unable to
  23. Chemistry

    If the partial pressure of CO2 is 2.87 atm the soluability in H2O is known to be 4.68 M. What would be the soluability of CO2 in H2O if the partial pressure is increased to 7.60 atm? Assume the temp is held constant. would it work to set up a proportion
  24. Chemistry

    The volume of the nitrogen gas is 125ml atmospheric pressure is 763mm Hg Water temperature is 24 degrees Celcius. The water level inside the eudiometer is the same as the level of water in the beaker. Calculate the pressure of the dry nitrogen gas.
  25. Chem II

    A sample of gas in a 21.5-L container at 45 degrees Celsius is cooled at constant pressure to a temperature of -37 degrees Celsius at constant pressure. Determine the volume of the cooled gas.
  26. chemistry

    a container with an initial volume of 6 liters at a temperature of 30 degrees celsius with a pressure of 2atm is changed so the temperature is now 90 degrees celsius and the volume is 8 liters. calculate the new pressure
  27. calculus

    When air expands adiabatically (without gaining or losing heat), its pressure and volume are related by the equation PV^1,4=C where C is a constant. Suppose that a a certain instant the volume is 520 cubic centimeters and the pressure is 99kPa and is
  28. chemistry

    A certain amount of chlorine gas was placed inside a cylinder with a movable piston at one end. The initial volume was 3.00 L and the initial pressure of chlorine was 1.15 atm . The piston was pushed down to change the volume to 1.00 L. Calculate the final
  29. Physics

    Lubricating oil, with a relative density of 0.79, flows around a 90¨¬ bend. The pipe diameter is 0.45m, and the oil has a pressure head of 7m and the flow is 1.7m3/s. Find the force exerted by the oil on the bend. Oil density = 0.79 X 103 Volumetric mass
  30. Physics

    Lubricating oil, with a relative density of 0.79, flows around a 90¨¬ bend. The pipe diameter is 0.45m, and the oil has a pressure head of 7m and the flow is 1.7m3/s. Find the force exerted by the oil on the bend. Oil density = 0.79 X 103 Volumetric mass
  31. Physics

    An ideal gas at 6.0°C and a pressure of 1.92 105 Pa occupies a volume of 2.10 m3. (a) How many moles of gas are present? moles (b) If the volume is raised to 4.60 m3 and the temperature raised to 30.5°C, what will be the pressure of the gas? Pa I was
  32. Chemistry

    Does anyone know of any sites that make learning to balance equations easy? I just transferred to a new school and the chemistry class is way ahead of my old class. I really don't get it. Please help since there is a test tomorrow and it's on stuff that
  33. chemistry

    I have a question in chemistry relating to identifying a compound that would precipitate the iron ions out of a water supply. I am unsure of a compound that would react to produce the iron as a precipitate that could be removed. Thoughts?
  34. Chemistry

    For a chemistry lab, I have to calculate the heat of combustion of paraffin wax. So how would I do that? And for the second part of the lab, I have to calculate the heat of fusion of ice from my data. How would I do that? I'm kind of confused so can I get
  35. chemistry

    i have to do a "chemistry of cooking" project for my chem class. for the project i need to convert pounds, grams, and ounces into moles, but i do not know how. for example, i need to convert 453.5g of beef into mols. how do i do that? do i need to know the
  36. chemistry

    can you please give me one practical application of analytical chemistry in being a medical technologist? i know it will determine the separation event happening on the lab test... but is that already a practical application? or i have to cite a deeper
  37. chem

    Methyl alcohol can be used as a fuel instead of, or combined with, gasoline. A sample of methyl alcohol, CH3OH, in a flask at constant volume exerts a pressure of 254 mm Hg at 57 degrees C. The flask is slowly cooled. a) assuming no condensation, use the
  38. Chemistry

    A mixture of ethyne ( C2H2 ) and methane ( CH4 ) occupied a certain volume at a total pressure of 16.8 kPa. Upon burning the sample to form CO2 and H2O, the CO2 was collected and its pressure found to be 25.6 kPa in the same volume and at the same
  39. Chemistry

    What is the vapor pressure of a solution prepares by dissolving 4.25g of K2O in enough water to preapare 1.25L of Solution at 25 degrees (C)? Assume that the density of the solution is 1.00 g/mL and that the vapor pressure of pure water is 23.8 torr at 25
  40. Chemistry

    I forgot in my previous question to say 1014 millibars. The question is I live at 1014 millibars for barometric pressure and temp. is 61 degrees Fahrenheit. I have an imaginary balloon that contains 22 grams of CO2-what is the volume in liters of the
  41. Chemistry

    A eudiometer contains 65.0 ml sample of gas collected by the diplacement of water. The water levels inside and outside the eudiometer are the same. The atmospheric pressure is 92.5 kPa and the temperture is 23 degrees. What volume will the dry gas occupy
  42. engineering

    I am studying Fire Science Engineering. I have a question concerning my homework. The question is A compartment measures 3 meters by 5 meters and is 2.8 meters high. A fire raises the temperature from 20 degrees C to 1000 degrees C. If the starting
  43. chemistry

    If the concentration of CO2 is 2.90 g of CO2 per 1.00 L of soft drink when bottled under 2.0 atm of CO2 pressure, what will be the concentration of the CO2 in the drink after it has been opened and left to come to equilibrium with the atmosphere which has
  44. chemistry

    If the concentration of CO2 is 2.90 g of CO2 per 1.00 L of soft drink when bottled under 2.0 atm of CO2 pressure, what will be the concentration of the CO2 in the drink after it has been opened and left to come to equilibrium with the atmosphere which has
  45. chem

    how is the oxide of arsenic worked out when its in its gas state please help im flumuxed Please clarify your question? What do you mean by "worked out? the question states determine the molecular formular of the oxide of arsenic when it is in its gaseous
  46. Chemistry

    The initial pressure for the compounds involved in the reaction shown were determined to be P(Br2(g)) = 0.5417 atm, P(Cl2(g)) = 0.6962 atm, P(BrCl(g)) = 0.3442 atm. Calculate the value of the equilibrium constant (Kp) at 1000 K if the equilibrium pressure
  47. science

    If the inner core reaches temperatures exceeding 6000c, in what phase/state of matter would these matters exist? A. gas; the temperature is so great that the atoms vaporize B. solid; the pressure is so great that the atoms are forced together C. liquid;
  48. chemistry

    Initially a vessel is charged at 1000K with SO3 at a partial pressure of 0.5atm. At equilibrium the SO3 partial pressure is 0.2atm. Calculate the value of Kp at 1000K. 2SO3->2SO2+O2 My answer: 0.5-0.2=0.3atm SO2=0.3atm*2/2mol= 0.3 O2=0.3atm*1/2mol=0.8
  49. chemistry

    Initially a vessel is charged at 1000K with SO3 at a partial pressure of 0.5atm. At equilibrium the SO3 partial pressure is 0.2atm. Calculate the value of Kp at 1000K. 2SO3->2SO2+O2 My answer: 0.5-0.2=0.3atm SO2=0.3atm*2/2mol= 0.3 O2=0.3atm*1/2mol=0.8
  50. Chemistry

    A sample of gaseous PCl5 was introduced into an evacuated flask so that the pressure of pure PCl5 would be 0.54 atm at 425 K. However, PCl5 decomposes to gaseous PCl3 and Cl2, and the actual pressure in the flask was found to be 0.85 atm. Calculate Kp for
  51. chemistry

    maintain room at partial pressure of water of 12 torr. the room is 20 degrees celcuis and relitive humidity is reading 52% 1. what is the partial pressur of water in the air in the room? 2. Equibrium vapor pressure of water at 20 degrees celcius is 17.5
  52. Chem

    Which of the following are correct statements? (Could be as many as 4) 1. One mole of gas contains 22.4 representative particles 2. Standard pressure is 100 mm Hg 3. One mole of a gas must have the same volume as one mole of any other gas at STP 4. Gas
  53. General Chemistry

    A 0.1358g zinc metal reacts completely with Dil HCL to produce 52.20ml of H2(g) at 22.0 degrees Celsius. The hydrogen gas is collected over water at 22.0 degree Celsius and a barometric pressure of 755 mm Hg. The water vapor pressure at 22.0 degrees
  54. Physics

    To supply the plumbing system of a New York office building, water needs to be pumped to a tank on the roof, where its height will provide a "head" of pressure for all the floors. The vertical height between the basement pump and the level of the water in
  55. Chemistry

    I have 25 million gallons of water at a pH of 6.5. I add 17.4 million gallons of 12.5% by wt sodium hypochlorite (NaClO) at a pH of 12.5 to this water. What will my pH of my final solution be? It's been about 5 years since I took chemistry and I just don't
  56. DMMS

    Chemistry What characteristics are shared by all alkali metals and alkaline earth metals? A They conduct electricity very well B They are strong and shiny C They form alkaline solutions when mixed with water D They do not react with water at all
  57. chemistry

    which of the following is true regarding the inner transition elements? A. their valence electrons can be located in both s and f sublevels B. They occupy the d block of the periodic table C. These include the lanthanides and actinides and do not have f
  58. Chemistry

    Aspirin can be prepared in the chemistry laboratory by the reaction of salicylic acid with acetic anhydride. What volume of acetic anhydride is required to produce one killogram of aspirin assuming 100%yield
  59. Sampling Distribution

    Sampling Distribution Complete solutions and illustrations are required. 3.The mean systolic blood pressure of normal adults is 120 millimeters of mercury (mm Hg) and the standard deviation is 5.6. Assume that the variable is normally distributed. a.If an
  60. Chemistry

    A sample of H2 is collected over water such that the combined hydrogen–water vapor sample is held at a pressure of 1 standard atmosphere. What is the partial pressure of the H2 if that of the water vapor is 2.5 kPa? A. 103.8 kPa B. 98.8 kPa C. 2.5 kPa D.
  61. Science

    A chemistry teacher needs to prepare 750 ml of a 2.5M solution of Potassium iodide for a lab. How many grams of potassium iodide will be needed to make the solution?
  62. math/ chemistry

    so I have this chemistry problem which involves math and basically I need to convert 62 g/mol into mol/L but I don't know how. like do you DIVIDE the g/mol by 1000 to convert g to L? and then how to you get the mol to become the numerator?
  63. physics

    A closed inexpansible vessel contains air saturated with water vapour at 77 degree Celsius.The total pressure in the vessel is 1007mmHg.Calculate the new pressure if the temperature is reduced at 27 degree Celsius (S.V.P of water at 77degree celcius and 27
  64. Chemistry

    Why use Methyl tert-butyl ether in the organic chemistry lab when separating compounds? separating WHAT compounds and how? as a solvent? It has a low boiling point and isn't very reactive, generally, but there may be other specific reasons depending upon
  65. Biology

    How do you balance equations? http://www.chemistry.ohio-state.edu/betha/nealChemBal/ The reactants are written on the left and the products on the right.An arrow pointing towards the product is inserted between the reactant and product.The number of
  66. Physics

    Water from the dead sea flows into a pipe of diameter 18cm at a velocity of 5.0m s at pressure 4.0atm. The pipe reduces to a diameter of 10cm at a point 3.5m above. a)Determine the rate of flow. b)Determine the velocity at the top section. c)Determine the
  67. Chemistry 11 grade -

    Hydrogen gas was collected in a gas-collecting bottle with a volume of 30.0 mL by water displacement on a day where the temperature was 24ºC and the barometric pressure was 98.125 kPa. The vapour pressure of water at 24ºC is 2.99 kPa. What would be the
  68. Physical Education

    Preliminary design of a compressor drive train Determine the force-time function within the compressor’s cylinder and the torque-time function acting on the input shaft on the compressor during any cycle. Given: Compressor speed is 1500rpm. The
  69. Chem

    A flask of unknown volume was filled with air at a pressure of 389.0 kPa. The flask was attached to an evacuated flask of 32.0 L and the air was allowed to expand into the second flask. At equilibrium, the final pressure was 154.0 kPa. Calculate the volume
  70. Chemistry

    I need help with part b here's all information. (a) Chlorine gas is added to a glass cylinder of 2.5 cm in radius, fitted with a movable piston. Gas is added until the piston is lifted 5 cm off the bottom of the glass. The pressure on the gas is 1 atm, and
  71. CHM 312L

    Experiment: Thermodynamics of Real Gases Chemistry 311L (Heat Capacity Ratio and the Joule-Thomson Effect) question: Imagine that you forget that an oil manometer measures pressures above atmospheric. What will happen to your calculated heat capacity
  72. science

    A mixture of benzenoic acid aniline and phenol is dissolved in chroloform and the solution was treated with sodium hydroxide.hydrochloric acid and sodium bicarbonate.show the separation chart,identify the composition of each phase and explain the chemistry
  73. Science

    Sir, I am Raveesh, I have done my M.Sc in Botany and B.Ed in Chemistry and Biology. Now i am working as a Lecturer in a college from last 2 years. I really interested to do online tutoring as a TUTOR / e-tutor. But I don't know how to do? Because I stay in
  74. AP Chemistry

    Part 1 of 3: An apparatus consists of a 2 L flask containing nitrogen gas at 30 degrees C and 758 kPa, joined by a valve to a 11 L flask containing argon gas at 30 degrees C and 49.7 kPa. The valve is opened and the gases mix. What is the partial pressure
  75. Ap Chemistry

    Posted by Jake on Sunday, September 23, 2007 at 1:08pm. My objective is to find the molar volume of a gas. Is this the correct balanced equation for magnesium ribbon reacting with hydrochloric acid to form hydrogen gas? 2Mg (s) + 2HCL (l) ----> H2 (g) +
  76. physic

    a pipe is 40% blocked the water is coming into the region is moving at 8.5cm/s just before the blocked segment of pipe. What is the speed of the water as it goes through the partially blocked segment? By how many pascals does the pressure in the blocked
  77. Math

    Stupid question time. I need to figure out how to rearrange equations to solve for x in my chemistry homework, which involves putting equations in quadratic form first. But I can't for the life of me remember how to "rearrange" them correctly. So what in
  78. Chemistry - HELP IGCSE

    I have a chemistry exam tomorrow and I don't get the double bonding in covalent bonding I tried many websites , textbooks and other books and yet nothing worked Can someone please explain it clearely and in a simple way and please don't put any links for
  79. chemistry

    So I have to make a green cleaner for a project in chemistry. I think my ingredients should be: vinegar, salt, water, and lemon juice. But I don't know how I would write that exactly as a chemical formula. How could I write a chemical equation if I have 4
  80. Chemistry

    A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr? I am coming out with 443torr, but the listed options are 80.0
  81. Fluid Mechanics

    The components and their dimensions of a hydraulic jack are shown in the figure. The specific gravity of the fluid in the jack is SG=0.8. A force F=400 N is applied at the left end of the handle, which is hinged at the right end. Determine: (a) The fluid
  82. Chemistry

    1. What happens to the altitude and pressure when the boiling point is lowered? 2. What happens to the altitude and boiling point when the pressure is increased?
  83. Chemistry

    You are completing tests using a weather balloon and want to check the temperature at 3000 meters into the air. You check if the balloon will not burst before it gets to that altitude. You will need to perform a few calculations. The manufacturer of the
  84. physics

    Water is circulating through a closed system of pipes in a two- floor apartment. On the first floor, the water has a gauge pressure of 3.4*10^5 Pa and a speed of 2.1 m/s. However, on the second floor, which is 4.0 m higher, the speed of the water is 3.7
  85. chemistry

    1. Mass of flask, boiling chips, foil cap and unknown after cooling reaction 83.350g 2. Mass of flask, boiling chips and foil cap. 82.657 3. water bath temperature C 95.0 C 4. Barometric pressure in Hg 30.09 5. Accepted molar mass of unknown 86.2g/moles 6.
  86. Chemistry

    Explain in terms of forces between structural units why H2O2 has a higher melting point than C3H8. Also, which between the two examples has a lower boiling point? NH3 or AsH3 C3H7OH or C2H5OCH3 Can you possibly give me a good website that simply explains

    For chemistry I have to make a comic strip about gold. The comic strip has to included all the important facts i.e. atomic mass, symbol, weight,etc... Any suggestions on what my comic strip could be or any ideas. Thanks ahead for you help.
  88. Chemistry

    A mixture of Nitrogen and Argon gases in a balloon exerted a pressure of 2.55 atm. Given that there were 1.0 g nitrogen gas and 3.2 g argon gas in the balloon, calculate the partial pressure of argon gas.
  89. Heat and properties of matter

    1. Which of the following is not true a. Evaporation occurs at any temprature of a liquid b. Boiling takes place only at the surface of the liquid c. Evaporation occursonly at the surface of a liquid d. Boiling of a liquid takes place at a definite
  90. Physics

    please I and my friend has been trying this one. If there there are 2.7*10^19 molecules are there in 1.0cm3 of a gas at 273k and pressure 1.0*10 ^5Pa. How many molecules are there in 1.0cm3 of the gas at 350k and pressure 1.0*10 ^5Pa.
  91. Chem Help Please!!!

    a) The equipment you would use for carrying out a simple distillation at reduced pressure (i.e. under vacuum) b) the equipment you would use for carrying out a simple distillation at atmospheric pressure. Thanks!
  92. chemistry

    A certain gas has a volume of 20 cu ft and a pressure of 10psia at -40 degrees F. What is the new pressure if the gas is compressed to 5 cu ft at -40 degrees C.. a. 0.025 psia b. 0.4 psia c. 10 psia d. 40 psia.
  93. Chemistry

    A gas occupies a volume of 200cm*cm*cm at a temperature of 27'C and 760mm pressure.Find the volume of gas at a temperature of -3'C at 760mm pressure?
  94. Ellison

    A cylinder that contains methane gas is kept at a temperature of 15°C and exert a pressure of 7atm.If the temperature of the cylinder increases to 25°C,what pressure does the gas now exert?
  95. College Chemistry

    When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial pressure of the dry air
  96. Chemistry

    the air in a steel belted tire is at a gauge pressure of 29.8 psi at a temperature of 20 degrees celsius. After the tire is driven out fast on a hot road, the temperature in the tire is 48 degrees celsius. What is the tires new gauge pressure. Can someone
  97. Chemistry-Urgent

    The partial pressure of CO2 inside a bottle of soft drink is 4.0 atm at 25°C. The solubility of CO2 is 0.12 mol/L. When the bottle is opened, the partial pressure drops to 3.0 ✕ 10-4 atm. What is the solubility of CO2 in the open drink? Express your
  98. Chemistry

    A solution contains naphthalene (C10H8) dissolved in hexane (C6H14) at a concentration of 15.00% naphthalene by mass. Calculate the vapor pressure at 25 ∘C of hexane above the solution. The vapor pressure of pure hexane at 25 ∘C is 151 torr. I keep
  99. Physics

    A water pipe is inclined 31.0° below the horizontal. The radius of the pipe at the upper end is 2.00 cm. If the gauge pressure at a point at the upper end is 0.122 atm, what is the gauge pressure at a point 2.70 m downstream, where the pipe has narrowed
  100. College Chemistry

    When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial pressure of the dry air