Documents about Mole Fractions

  • 11 Pages


    University of Michigan, CHEM 230

    Excerpt: ... r a day or so has passed work some additional problems to reinforce your understanding of the section you have been studying. From the lecture 3 6NaN3(s) + Fe2O3(s) 3Na2O(s) + 2 Fe(s) + 9N2(g) This is the reaction that inflates "air bags" in cars. Is it balanced? We need to produce 100.8 L of N2 at 273K and 1 atm. 1) How many grams of NaN3 should I use? 2) Since NaN3 is a energetic material we need to completely react the entire amount used. How much Fe2O3 do I need to sure to insure that sodium azide is the limiting reagent? Take four minutes to work through these two problems using the 5 step method. Compare your method and results with your neighbors. Ideal Gases Act Independently Since there are no interaction between the gas particles each gas particle behaves independently Partial pressures are additive Ptot = Pa+Pb+Pc Ideal gas equation for component"a" PaV = naRT Mole fractions for component"a" na/ntot = Pa/Ptot For ideal gases Components in a gas mix ...

  • 5 Pages


    Rensselaer Polytechnic Institute, PCHEM 2008

    Excerpt: ... HOMEWORK CHEM 4410 Instructor: Ryu The objective of this homework is to serve as a study guide. Please do not submit the homework. This will NOT be graded. But, remember that this could be one of the questions in the quiz! Homework 10 1. Please us ...

  • 1 Pages


    Michigan State University, LBS 172

    Excerpt: ... Concept Mapping Assignment-Due 2/2/05 Objective: Create a map that shows the information required to convert between the following concentration units: molarity, molality, mole fraction, weight percent, and parts per million (ppm). Examples: total pr ...

  • 3 Pages

    18-Advanced Topics in Gas Laws

    University of Texas, CH 53750

    Excerpt: ... 1 atm at these conditions. However, if we were to isolate the hydrogen we'd find a pressure of 2.9 atm; isolating the helium and measuring the pressure would yield 7.2 atm. Note how the mixture (hydrogen + helium) has a total pressure which is equal to the sum of the individual pressures exerted by just the hydrogen and just the helium. Mathematically, we can write: PTotal = P1 + P2 + P3 + P4 + P5 + Where the subscripts represent each individual component in the mix. Using Partial Pressures An important result of Dalton's law is that if we have a gas mixture, and we know the number of moles of each gas comprising the mix, we can easily write the total pressure for the gas mixture: RT RT P T o ta l = ( n 1 + n 2 + n 3 + . . . ) = n T o ta l V V Partial Pressures with Mole Fractions We can introduce a new quantity (think of this as a concentration) called the mole fraction. Mole fractions should only be written for mixtures, as they express the moles of each indi ...

  • 1 Pages

    In class notes for October 8, 2007

    Vanderbilt, CHEM 102a

    Excerpt: ... General Chemistry Lecture 102a In class notes for October 8, 2007 Chapter 5 OWL due Thursday at 11:59 pm Exam #2 a week from Thursday Dont say a word! Last Lecture Partial pressures, mole fraction Kinetic Theory (Assumptions) Today Kinetic Th ...

  • 2 Pages


    University of Alabama in Huntsville, CHE 441

    Excerpt: ... nter the temperature and pressure. Enter the total molar flow rate. You will have to calculate this value a priori (via ideal gas law). For 'Comp Unit' select 'mole fraction'. Then enter the appropriate mole fractions for the inlet stream. Click 'OK'. 1 Now we are ready to run the simulation. Select 'run all' in 'Run' menu. If one entered all of the correct information, one should see a "Run Finished" message at lower left corner of screen. If errors exist, a window will appear which defines/describes the errors. When the simulation runs without errors, open the outlet stream. View the stream's mole fractions . Do they agree with the mole fractions indicated on the mathcad sheet for this example (website)? Now to generate a plot of mole fractions versus reactor position. Go to 'Run' menu and select 'Sensitivity Study'. Select 'New Analysis'. Enter a name for the analysis. Click on 'Edit Independent Variable'. Select 'Equipment'. Enter number given to reactor on flowsheet (in ...

  • 2 Pages


    N.C. State, CH 331

    Excerpt: ... Chemistry 331 Lecture 16 Non-ideal solutions Non-ideal solutions Many solutions are not ideal. For ideal solutions the role of intermolecular interactions can be ignored. This may be because they are small or because two components have the same int ...

  • 4 Pages

    web Lec10 3pp

    Sveriges lantbruksuniversitet, C 121

    Excerpt: ... Lecture 10 Wednesday, January 28 Gases, Chapter 5 5.1 5.3 The Gas Laws (from last notes) 5.4 Gas Stoichiometry 5.5 Dalton's Law of Partial Pressure 1 Demo: The Oxidation States of Manganese Balance these equations prior to class, and be ready for ...

  • 5 Pages


    Rowan, COMBUSTION 06

    Excerpt: ... n species divided by the total number of moles: (2.8) Mass fraction (Yi) is the mass of a certain species divided by the total mass of all species: (2.9) Note that, by definition, the summation of mole fractions and mass fractions of a gas mixture =1: (2.10) Parts per million (ppm) is actually the mole fraction multiplied by 1000000. D. Molecular Weight of a Gas Mixture Given either the mole fractions or mass fractions of a gas mixture, it is possible to calculate the average molecular weight of a gas mixture: (2.12) E. Conversion from Mole Fraction to Mass Fraction To convert from mole fraction to mass fraction and vice versa, us the following relationships: (2.11) 0910411 / 0910511 Week 1 Combustion Course Overview and Properties of Gas Mixtures Class Notes - Page: 11 Text: Ch.1, Ch.2 (9-32) F. Partial Pressure The partial pressure of a given species in a gas mixture is the pressure that would result if that species were isolated from the rest of the mixture at the same temperature and volume: Fo ...

  • 4 Pages


    Indiana University-Purdue University Fort Wayne, MA 153

    Excerpt: ... vapor pressure of mole partial vapor pentane, ppentane , in a solution which has mole fractions of fraction of pressure of pentane, Xpentane = 1/4, 1/2, and 3/4. Complete Table III. pentane, pentane, Check that this is consistent with your graph above. Xpentane ppentane Note: These values are different than the ones in Table II, 1/4 where you found the total vapor pressure of the solution. 1/2 3/4 4. Use Table I to complete the blanks: a. In a sample of 100% octane, the mole fraction of octane Xoctane = _ and its vapor pressure is _. b. In a sample of 100% pentane, the mole fraction of octane Xoctane = _ and the vapor pressure of octane is _. c. Plot these values on the set of axes for Graph II on the last page. d. This graph gives the partial vapor pressure of octtane, poctane in a solution which has a mole fraction of octane, Xoctane . It is directly proportional to the mole fraction of octane in the solution. Sketch a line through these two points using a straightedge. Give an equati ...

  • 2 Pages

    In class notes for October 17, 2007

    Vanderbilt, CHEM 102a

    Excerpt: ... General Chemistry Lecture In class notes for October 17, 2007 Exam #2 7-9pm Thursday Furman 114 Chapter 4 Acide base to Chapter 6-6 concentration units Some stuff available Units of pressure (1atm=760torr=) Units of R (0.0821 (L x atm)/(mol K) ...

  • 6 Pages


    Hope, CHEM 111

    Excerpt: ... 9/24/01 CHEM 111-02 My Scout week-end at Makinac Anything exciting on campus? Chem Major presentation on Friday - response? NOTE: 1st hour exam is in one week. ChemBoard Will someone help me with # 7? Homework set # 11 due today, discussion at 4:00 Quiz #3 key posted by tonight (sorry for delay) Examples of mole fractions and partial pressure Gases in the atmosphere A demo quiz Mole fractions and Partial pressure Since each gas in a mixture behaves in an ideal manner we can say Ptotal = pa + pb + pc + where pa is partial pressure of component a Ptotal = ntotalRT/V and pa = naRT/V So pa/Ptotal = na/ntotal = Xa = mole fraction a Or Xa Ptotal = pa A sample of air contained CO at a concentration of 35 ppm and water vapor at a pressure of 9 mm Hg. The air temp is 29 C and the atmospheric pressure is 745 torr. - What is the mole fraction of CO? of H2O? - What is the partial pressure of CO? Of H2O - How many molecules of CO are in 1.0 x 103 L of ...

  • 18 Pages


    Pittsburgh, CHE 1008

    Excerpt: ... Other Equilibrium Relationships Relative Volatility It will be convenient later on in separation problems to express the relative volatility in terms of the mole fractions and vice-versa For binary systems, the mole fractions are related by y B = 1 - y A and x B = 1 - x A and substituting these into Eq. (2-20) yields: Eq. (2-4) AB = y A (1 - x A ) (1 - y A )x A 1 - xA 1 - yA Eq. (2-22) or AB = K A Solving Eq. (2-22) for yA and xA yields: yA = AB x A 1 + ( AB - 1) x A yA AB - ( AB - 1) y A Eq. (2-23) and xA = Lecture 6 1 Calculation of BubblePoint and DewPoint Temperatures The bubblepoint temperature is the temperature at which a liquid mixture begins to boil. The dewpoint temperature is the temperature at which a vapor mixture first begins to condense. Lecture 6 2 Temperature-Composition Diagram for Ethanol-Water, P = 1 atm 100 95 Two Phase Superheated Vapor Phase 90 T( C) 85 80 Subcooled Liquid Phase o 75 0.0 0.2 0.4 zEtOH 0.6 0.8 1.0 3 xEtOH or yEtOH Lecture 6 Calcu ...

  • 7 Pages


    N.C. State, CH 433

    Excerpt: ... 10/27/2008 Chemistry 433 Lecture 21 Totalderivativefortwocomponents Weconsiderthethermodynamicsoftwocomponent systems.Theideasdiscussedhereareeasily generalizedtomulticomponent systems.Forasolution consistingofn molesofcomponent1andn molesof consis ...

  • 13 Pages


    E. Kentucky, CPE 211

    Excerpt: ... , you were taught that: 1 mole = 6.0223 1023 molecules (Avogadro's number of a substance. And: the mass of 1 mole = Molecular Weight in g. In Chemical Engineering, we extend that definition to include other units of mass: g-mole (mol) lb-mole kg-mole (kmol) etc. How many molecules in a lb-mole? MW (g) MW(lbm) MW(kg) Table B.1 gives molecular weights for a number of compounds. If, you can't find the compound you need in Table B.1, compute its molecular weight from the compounds listed in the back cover of your book. CPE 211, F01 Lecture 4, Page 7 Example: Calculate the g-moles and lb-moles in 1.00 kg of ethane (C2H6). CPE 211, F01 Lecture 4, Page 8 Mass and Mole Fractions for n components: Mass Fraction = yi = wi n wi i =1 Where wi is the mass of component i. Mass Percent = 100% (Mass Fraction). Mole Fraction = yi = mi Where mi is the mass of component i. mi i =1 n Mole Percent = 100% (Mole Fraction). Example: CPE 211, F01 Lecture 4, Page 9 Now, we could calculate mass percent from the mass ...

  • 1 Pages


    Cal Poly, CHEM 125

    Excerpt: ... Chem 125 Spring 2009 Dr. Retsek Study Guide for Exam Two (Part 2) What should you know from the complex ion lab? What is going on at the atomic level in the regions of low absorbance with low mole fraction of ligand, low absorbance with high mole ...

  • 2 Pages

    Requirment for Stoichiometry

    Virginia Tech, CHEM 1045

    Excerpt: ... Date performed: Date submitted: Instructor: Name: Partner: Title Objective A brief statement of the objective. Main point for the goal of the lab; Experimental Data List your datas in a table which should have five columns ( in right order from le ...