DOCSLIB.ORG

Vapor Intrusion Technical Guidance

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION SITE REMEDIATION AND WASTE MANAGEMENT PROGRAM VAPOR INTRUSION TECHNICAL GUIDANCE Indoor Air Soil Gas Ground Water May 2021 Version 5.0 New Jersey Department of Environmental Protection Site Remediation and Waste Management Program Vapor Intrusion Technical Guidance May 2021 Version 5.0 2 ACKNOWLEDGEMENTS The New Jersey Department of Environmental Protection (Department) Vapor Intrusion Technical Guidance (Version 4.1) document was previously prepared by the Department/Stakeholder Vapor Intrusion Guidance Committee in cooperation with the Department Vapor Intrusion Committee. The updated Vapor Intrusion Technical Guidance (Version 5.0) was completed by the Department with assistance from the Stakeholder Vapor Intrusion Guidance Committee. Department/Stakeholder Vapor Intrusion Guidance Committee Carey Compton, Chair, New Jersey Department of Environmental Protection Nicole Kalaigian, New Jersey Department of Environmental Protection John Boyer, New Jersey Department of Environmental Protection Retiree Ken Bird, Woodard & Curran Consultants Brian Blum, Langan Consultants Scott Drew, Geosyntec Consultants John Engdahl, Speedway Erica Snyder, New Jersey Department of Environmental Protection Diane Groth, New Jersey Department of Environmental Protection Retiree Andrew Sites, New Jersey Department of Environmental Protection Retiree Peter Sorge, JM Sorge, Inc., Environmental Consultants Chad VanSciver, New Jersey Department of Environmental Protection Additional Technical Assistance: Gunnar Barr, OBAR Systems Bill Morris, Vapor Mitigation Sciences Special thanks for the assistance of the following individuals from the Department: Bridget Sweeney Barry Frasco Tracy Grabiak, Retiree Kathy Kunze, Retiree George Nicholas, Retiree Sana Qureshi Paul Sanders Kevin Schick Paul Bauer Teruo Sugihara, Retiree David Haymes Cover graphic courtesy of the Interstate Technology & Regulatory Council (ITRC). 3 DISCLAIMER The use of any trade names, products or materials in this document does not constitute an endorsement by the State of New Jersey’s Department of Environmental Protection (Department). The information in the Department’s Vapor Intrusion Technical Guidance (Version 5.0) document is provided free of charge to the public. The State of New Jersey, its agencies and employees assume no responsibility to any person or entity for the use of this information. There are no representations or warranties, expressed or implied, of any kind regarding this information, and any use of this information is made at the risk of the user. Neither the Department nor the State of New Jersey maintains many of the web links and web addresses in the Department’s Vapor Intrusion Technical Guidance (Version 5.0). The Department makes no special endorsement for the content of these links, their sites or the views expressed by the sites’ publishers. Websites may change or remove their contents at any time. Therefore, the Department cannot guarantee that the material on the referenced websites will be the same as it was when the Vapor Intrusion Technical Guidance (Version 5.0) was developed or even that the links will be available. Trademarks (e.g., Microsoft Word, Adobe Acrobat) belong to their respective companies. 4 NJDEP Vapor Intrusion Technical Guidance (Version 5.0) May 2021 TABLE OF CONTENTS ACKNOWLEDGEMENTS ........................................................................................................................................... 3 DISCLAIMER .............................................................................................................................................................. 4 TABLE OF CONTENTS .............................................................................................................................................. 5 EXECUTIVE SUMMARY ........................................................................................................................................... 9 1.0 INTRODUCTION ........................................................................................................................................ 10 1.1 Intended Use of this Technical Guidance ....................................................................................... 10 1.2 Overview of this Guidance .............................................................................................................. 10 1.3 Department-Generated Variances .................................................................................................. 12 1.4 Guidance Updates ........................................................................................................................... 12 2.0 RECEPTOR EVALUATION & SCREENING (STEPS 1 AND 2) ............................................................ 13 2.1 VI Triggers ...................................................................................................................................... 13 2.1.1 Trigger Distances ............................................................................................................. 13 2.1.2 Dissolved Ground Water Exceedance of GWSL ............................................................... 14 2.1.3 Presence of Free and Residual Product ........................................................................... 15 2.1.4 Soil Gas Exceedance of SGSL .......................................................................................... 15 2.1.5 Indoor Air Exceedance of IARS or Rapid Action Levels ................................................... 16 2.1.6 Presence of Ground Water Contamination or Free Product in a Wet Basement or Sump ............................................................................................................................. 16 2.1.7 Presence of Methanogenic Conditions ............................................................................. 16 2.1.8 Other Conditions That May Impact Human Health and Safety ........................................ 16 2.1.9 Volatile Soil Contamination .............................................................................................. 16 2.2 Vapor Intrusion Indoor Air Remediation Standards & Vapor Intrusion Screening Levels ............ 17 2.3 VI Receptor Evaluation (Step 1) ..................................................................................................... 17 2.3.1 Initial Data Gathering ...................................................................................................... 17 2.3.2 Building and Structures .................................................................................................... 18 2.3.3 Conceptual Site Model ...................................................................................................... 19 2.3.4 Preferential Pathways ...................................................................................................... 19 2.3.5 Landfills and Methane Gas ............................................................................................... 20 2.4 Petroleum VI Screening (Step 2) ..................................................................................................... 21 3.0 VAPOR INTRUSION INVESTIGATION (STEP 3) .................................................................................. 22 3.1 Preparing for a Vapor Intrusion Investigation ............................................................................... 22 3.1.1 Investigative Approach ..................................................................................................... 22 3.1.2 Access ............................................................................................................................... 23 3.1.3 Iterative Nature of VI Investigations ................................................................................. 24 3.1.4 Field Analysis in Support of Vapor Intrusion Investigations ............................................ 25 3.2 Ground Water Investigation and Sampling ..................................................................................... 27 3.2.1. Saturated Zone Features Affecting Vapor Intrusion ......................................................... 28 3.2.2 Use of Pre-Existing Ground Water Data .......................................................................... 30 3.2.3 Obtaining New Ground Water Data to Evaluate the VI Pathway .................................... 31 3.3 Soil Gas Sampling ........................................................................................................................... 33 3.3.1 Sub-Slab Soil Gas Sampling ............................................................................................. 34 3.3.2 Alternative Soil Gas Sampling .......................................................................................... 38 3.4 Conducting a Building Walkthrough and Survey ............................................................................ 41 3.4.1 Identification of Potential Background Sources ............................................................... 41 3.4.2 Recognition of Points of Vapor Intrusion in a Building ................................................... 42 3.4.3 Identification of Possible Sample Locations ..................................................................... 42 3.4.4 Informing Occupants about Vapor Intrusion and Sampling Procedures .......................... 42 5 NJDEP Vapor Intrusion Technical Guidance (Version 5.0) May 2021 3.5 Indoor
Recommended publications
  • Evaluating Vapor Intrusion Pathways

    Evaluating Vapor Intrusion Pathways

    Evaluating Vapor Intrusion Pathways Guidance for ATSDR’s Division of Community Health Investigations October 31, 2016 Contents Acronym List ........................................................................................................................................................................... 1 Introduction ........................................................................................................................................................................... 2 What are the potential health risks from the vapor intrusion pathway? ............................................................................... 2 When should a vapor intrusion pathway be evaluated? ........................................................................................................ 3 Why is it so difficult to assess the public health hazard posed by the vapor intrusion pathway? .......................................... 3 What is the best approach for a public health evaluation of the vapor intrusion pathway? ................................................. 5 Public health evaluation.......................................................................................................................................................... 5 Vapor intrusion evaluation process outline ............................................................................................................................ 8 References… …......................................................................................................................................................................
  • Cambridge International Examinations Cambridge Ordinary Level

    Cambridge International Examinations Cambridge Ordinary Level

    Cambridge International Examinations Cambridge Ordinary Level HISTORY 2158/13 Paper 1 World Affairs, 1917–1991 May/June 2014 2 hours 30 minutes Additional Materials: Answer Booklet/Paper *9722304068* READ THESE INSTRUCTIONS FIRST If you have been given an Answer Booklet, follow the instructions on the front cover of the Booklet. Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer five questions. Section A Answer at least one question from this Section. Sections B to F Answer questions from at least two of these Sections. All questions in this paper carry equal marks. The first part of each question is worth 14 marks and the last part is worth 6 marks. Answer each part of the questions chosen as fully as you can. At the end of the examination, fasten all your work securely together. This document consists of 7 printed pages and 1 blank page. DC (LK) 90309 © UCLES 2014 [Turn over 2 Section A International Relations and Developments 1 Describe how the Treaty of Versailles: (a) changed the European borders of Germany; (b) brought Germany’s colonial empire to an end. How far do you agree that Germany was not treated fairly by the terms of the Treaty of Versailles? 2 Describe the main features of: (a) Mussolini’s conquest of Abyssinia in 1935–36; (b) Hitler’s taking of Austria and Czechoslovakia in 1938–39.
  • EPA's Vapor Intrusion Database: Evaluation and Characterization of Attenuation, Factors for Chlorinated Volatile Organic Compo

    EPA's Vapor Intrusion Database: Evaluation and Characterization of Attenuation, Factors for Chlorinated Volatile Organic Compo

    EPA 530-R-10-002 March 16, 2012 EPA’s Vapor Intrusion Database: Evaluation and Characterization of Attenuation Factors for Chlorinated Volatile Organic Compounds and Residential Buildings Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, DC 20460 March 16, 2012 EPA’s Vapor Intrusion Database [This page intentionally left blank.] ii March 16, 2012 EPA’s Vapor Intrusion Database Disclaimer This document presents technical information regarding the concentrations of chlorinated volatile organic compounds (VOCs) in and underneath North American buildings that have been investigated for potential vapor intrusion. This document does not confer legal rights, impose legal obligations, or implement any statutory or regulatory provisions. This document does not change or substitute for any statutory or regulatory provisions. U.S. Environmental Protection Agency (EPA) personnel (and others) are free to use and accept other technically sound information, either on their own initiative, or at the suggestion of responsible parties or other interested parties. Interested parties are free to raise questions and objections about the appropriateness of the information presented in this document. Finally, this is a living document and may be updated periodically. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. iii March 16, 2012 EPA’s Vapor Intrusion Database Authors and Contributors The U.S. Environmental Protection Agency (EPA), Office of Solid Waste and Emergency Response (OSWER), Washington, DC, was responsible for the preparation of EPA’s Vapor Intrusion Database: Evaluation and Characterization of Attenuation Factors for Chlorinated Volatile Organic Compounds and Residential Building. Dr. Helen E.
  • Palm Beach International Airport (PBI)

    Palm Beach International Airport (PBI)

    Agenda Item:~ PALM BEACH COUNTY BOARD OF COUNTY COMMISSIONERS AGENDA ITEM SUMMARY -===================================================================== Meeting Date: January 12, 2021 [ ] Consent [ X] Regular [ ] Ordinance [ ] Public Hearing Submitted By: Department of Airports ---------------------------------------------------------------------- I. EXECUTIVE BRIEF Motion and Title: Staff recommends motion to approve: a Contract for Air Service Development Consulting Services (Contract) with Ailevon Pacific Aviation Consulting LLC (Ailevon), a Florida limited liability company, commencing on February 1, 2021, and expiring on January 31, 2024, with one 24-month option to renew for an amount not to exceed $200,000 per contract year for a total not to exceed amount of $600,000 for the initial term. Summary: This Contract provides for professional and technical consulting services on an as-needed basis in support of the air service development program for the Palm Beach International Airport (PBI). Ailevon's principal place of business is Atlanta, GA. Air service development consulting services may include, but are not limited to, air service strategy and planning, airline route study and forecasting, competitive service analysis, business case development for new/expanded air service, development of incentive programs, catchment area demographic and leakage studies and analysis of air traffic demand and airfare data. The Contract provides for a not to exceed amount of $200,000 per contract year with an initial three-year term and an option to renew for an additional 24 months at the County's sole option. Due to lack of availability of qualified Small/Minority/Women Owned Business Enterprises providing the services required by this Contract, the Office of Equal Business Opportunity issued a waiver of Affirmative Procurement Initiatives on July 30, 2020.
  • User''s Guide for Evaluating Subsurface Vapor Intrusion Into Buildings

    User''s Guide for Evaluating Subsurface Vapor Intrusion Into Buildings

    USER'S GUIDE FOR EVALUATING SUBSURFACE VAPOR INTRUSION INTO BUILDINGS Prepared By Environmental Quality Management, Inc. Cedar Terrace Office Park, Suite 250 3325 Durham-Chapel Hill Boulevard Durham, North Carolina 27707-2646 Prepared For Industrial Economics Incorporated 2667 Massachusetts Avenue Cambridge, Massachusetts 02140 EPA Contract Number: 68-W-02-33 Work Assignment No. 004 PN 030224.0002 For Submittal to Janine Dinan, Work Assignment Manager U.S. ENVIRONMENTAL PROTECTION AGENCY OFFICE OF EMERGENCY AND REMEDIAL RESPONSE ARIEL RIOS BUILDING, 5202G 1200 PENNSYLVANIA AVENUE, NW WASHINGTON, D.C. 20460 Revised February 22, 2004 DISCLAIMER This document presents technical and policy recommendations based on current understanding of the phenomenon of subsurface vapor intrusion. This guidance does not impose any requirements or obligations on the U.S. Environmental Protection Agency (EPA) or on the owner/operators of sites that may be contaminated with volatile and toxic compounds. The sources of authority and requirements for addressing subsurface vapor intrusion are the applicable and relevants statutes and regulations.. This guidance addresses the assumptions and limitations that need to be considered in the evaluation of the vapor intrusion pathway. This guidance provides instructions on the use of the vapor transport model that originally was developed by P. Johnson and R. Ettinger in 1991 and subsequently modified by EPA in 1998, 2001, and again in November 2002. On November 29, 2002 EPA published Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils (Federal Register: November 29, 2002 Volume 67, Number 230 Page 71169-71172). This document is intended to be a companion for that guidance.
  • Chapter 3 Equations of State

    Chapter 3 Equations of State

    Chapter 3 Equations of State The simplest way to derive the Helmholtz function of a fluid is to directly integrate the equation of state with respect to volume (Sadus, 1992a, 1994). An equation of state can be applied to either vapour-liquid or supercritical phenomena without any conceptual difficulties. Therefore, in addition to liquid-liquid and vapour -liquid properties, it is also possible to determine transitions between these phenomena from the same inputs. All of the physical properties of the fluid except ideal gas are also simultaneously calculated. Many equations of state have been proposed in the literature with either an empirical, semi- empirical or theoretical basis. Comprehensive reviews can be found in the works of Martin (1979), Gubbins (1983), Anderko (1990), Sandler (1994), Economou and Donohue (1996), Wei and Sadus (2000) and Sengers et al. (2000). The van der Waals equation of state (1873) was the first equation to predict vapour-liquid coexistence. Later, the Redlich-Kwong equation of state (Redlich and Kwong, 1949) improved the accuracy of the van der Waals equation by proposing a temperature dependence for the attractive term. Soave (1972) and Peng and Robinson (1976) proposed additional modifications of the Redlich-Kwong equation to more accurately predict the vapour pressure, liquid density, and equilibria ratios. Guggenheim (1965) and Carnahan and Starling (1969) modified the repulsive term of van der Waals equation of state and obtained more accurate expressions for hard sphere systems. Christoforakos and Franck (1986) modified both the attractive and repulsive terms of van der Waals equation of state. Boublik (1981) extended the Carnahan-Starling hard sphere term to obtain an accurate equation for hard convex geometries.
  • Top 40 Singles Top 40 Albums

    Top 40 Singles Top 40 Albums

    12 May 2008 CHART #1616 Top 40 Singles Top 40 Albums Forever Don't Hold Back Unbreakable: 2008 NZ Tour Edition 50th Anniversary 1 Chris Brown 21 The Potbelleez 1 Westlife 21 Gray Bartlett Last week 5 / 3 weeks SBME Last week 22 / 12 weeks MOS/Universal Last week 10 / 22 weeks Platinum x1 / SBME Last week 17 / 3 weeks EMI Take A Bow Stop And Stare Rockferry Past, Present, Future 2 Rihanna 22 OneRepublic 2 Duffy 22 Tiki Taane Last week 4 / 2 weeks Universal Last week 18 / 17 weeks Universal Last week 3 / 5 weeks Gold x1 / Universal Last week 22 / 25 weeks Gold x1 / DirtyDub/Rhythm/DRM... Love In This Club Tattoo Flight Of The Conchords Rejoice 3 Usher feat. Young Jeezy 23 Jordin Sparks 3 Flight Of The Conchords 23 Katherine Jenkins Last week 1 / 10 weeks Gold x1 / SBME Last week 36 / 2 weeks SBME Last week 1 / 3 weeks Gold x1 / SubPop/Rhythmethod Last week 32 / 3 weeks Universal No Air Sorry Believe Legend: The Very Best Of 4 Jordin Sparks feat. Chris Brown 24 Buckcherry 4 Geoff Sewell 24 Willie Nelson Last week 2 / 10 weeks Platinum x1 / SBME Last week 26 / 6 weeks Universal Last week 2 / 4 weeks Gold x1 / SewellMusic/Ode Last week 18 / 6 weeks Gold x1 / SBME Lollipop What Is It? Back To Black: Deluxe Edition E=MC2 5 Lil Wayne 25 Baby Bash feat. Sean Kingston 5 Amy Winehouse 25 Mariah Carey Last week 6 / 3 weeks Universal Last week 33 / 6 weeks SBME Last week 6 / 49 weeks Platinum x2 / Universal Last week 20 / 3 weeks Universal 4 Minutes Party People The Swing Sessions Watershed 6 Madonna feat.
  • Greenhouse Gas Fluxes from Soils of Different Land-Use Types in a Hilly

    Greenhouse Gas Fluxes from Soils of Different Land-Use Types in a Hilly

    Available online at www.sciencedirect.com Agriculture, Ecosystems and Environment 124 (2008) 125–135 www.elsevier.com/locate/agee Greenhouse gas fluxes from soils of different land-use types in a hilly area of South China Hui Liu a,b, Ping Zhao a,*, Ping Lu c, Yue-Si Wang d, Yong-Biao Lin a, Xing-Quan Rao a a South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China b School of Tourism and Environment, Guangdong University of Business Studies, Guangzhou 510320, PR China c EWL Sciences, P.O. Box 39443, Winnellie, Northern Territory 0821, Australia d Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, PR China Received 15 October 2006; received in revised form 3 September 2007; accepted 11 September 2007 Available online 24 October 2007 Abstract The magnitude, temporal, and spatial patterns of greenhouse gas (hereafter referred to as GHG) fluxes from soils of plantation in the subtropical area of China are still highly uncertain. To contribute towards an improvement of actual estimates, soil CO2,CH4, and N2O fluxes were measured in two different land-use types in a hilly area of South China. This study showed 2 years continuous measurements (twice a week) of GHG fluxes from soils of a pine plantation and a longan orchard system. Impacts of environmental drivers (soil temperature and soil moisture), litter exclusion and land-use (vegetation versus orchard) were presented. Our results suggested that the plantation and orchard soils were weak sinks of atmospheric CH4 and significant sources of atmospheric CO2 and N2O. Annual mean GHG fluxes from soils of plantation À1 À1 À1 À1 and orchard were: CO2 fluxes of 4.70 and 14.72 Mg CO2–C ha year ,CH4 fluxes of À2.57 and À2.61 kg CH4–C ha year ,N2O fluxes À1 À1 of 3.03 and 8.64 kg N2O–N ha year , respectively.
  • Using Respiration Quotients to Track Changing Sources of Soil Respiration Seasonally and with Experimental Warming

    Using Respiration Quotients to Track Changing Sources of Soil Respiration Seasonally and with Experimental Warming

    Biogeosciences, 17, 3045–3055, 2020 https://doi.org/10.5194/bg-17-3045-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Using respiration quotients to track changing sources of soil respiration seasonally and with experimental warming Caitlin Hicks Pries1,2, Alon Angert3, Cristina Castanha2, Boaz Hilman3,a, and Margaret S. Torn2 1Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA 2Climate and Ecosystem Science Division, Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 3Institute of Earth Sciences, the Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel acurrently at: Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena 07745, Germany Correspondence: Caitlin Hicks Pries ([email protected]) Received: 7 June 2019 – Discussion started: 28 June 2019 Revised: 9 March 2020 – Accepted: 28 April 2020 – Published: 17 June 2020 Abstract. Developing a more mechanistic understanding of activity that may have utilized oxidized carbon substrates, soil respiration is hampered by the difficulty in determin- while growing-season values were lower in heated plots. Ex- ing the contribution of different organic substrates to respi- perimental warming and phenology change the sources of ration and in disentangling autotrophic-versus-heterotrophic soil respiration throughout the soil profile. The sensitivity of and aerobic-versus-anaerobic processes. Here, we use a rel- ARQ to these changes demonstrates its potential as a tool atively novel tool for better understanding soil respiration: for disentangling the biological sources contributing to soil the apparent respiration quotient (ARQ). The ARQ is the respiration. amount of CO2 produced in the soil divided by the amount of O2 consumed, and it changes according to which or- ganic substrates are being consumed and whether oxygen is being used as an electron acceptor.
  • Air Automated Manifest System

    Air Automated Manifest System

    AIR AUTOMATED MANIFEST SYSTEM FREQUENTLY ASKED QUESTIONS 1. Systems to be Used 2 2. Required and Voluntary Participation 2 3. When Air AMS Filing Required 4 4. Participant Procedures 4 5. Bond Requirements 5 6. Air AMS Documentation 6 7. Compliance Dates 7 8. Enforced Compliance Procedures – Phase 1 7 9. Enforced Compliance Procedures – Phase 2 9 10. Delivery Authorization 9 11. Split Shipments 10 12. Cargo that Fails to Arrive in the United States 11 13. Consolidated Shipments 11 14. Order of Receipt of Master and House Air Waybill 12 15. Simple and Master Air Waybill Format 12 16. House Air Waybill Format 13 17. In-bond Authorization 13 18. Permits to Transfer (Local Transfer) 15 19. Incomplete House Air Waybills 16 20. Manifest Holds 17 21. Foreign Cargo Remaining On Board (FROB) 17 22. Flights Without Cargo 18 23. Air AMS Problem Resolution 18 24. Scheduled Air AMS Downtime 19 25. Presentation of Documents 20 26. Manifest Discrepancy Reporting 20 27. Freight Report Inbound and Freight Report Change 20 28. Carrier Nomination/Agent Field 21 29. Emergency/Forced Landings 21 30. Location of Data Input 22 31. Duplicate Air Waybills 22 32. Quantity to Be Reported 22 33. Freight Status Information Messages 24 34. Carrier Codes 24 35. Company Material/Postal Mail/Letters and Documents 25 36. Code-Share Flights 25 37. Shipper/Consignee Information 27 38. Express Consignment Operations 29 1 Updated 07/25/2005 Updated Questions # 36 U.S. Customs and Border Protection (CBP) has received numerous questions concerning the regulations promulgated pursuant to the Trade Act of 2002.
  • Liquid-Vapor Equilibrium in a Binary System

    Liquid-Vapor Equilibrium in a Binary System

    Liquid-Vapor Equilibria in Binary Systems1 Purpose The purpose of this experiment is to study a binary liquid-vapor equilibrium of chloroform and acetone. Measurements of liquid and vapor compositions will be made by refractometry. The data will be treated according to equilibrium thermodynamic considerations, which are developed in the theory section. Theory Consider a liquid-gas equilibrium involving more than one species. By definition, an ideal solution is one in which the vapor pressure of a particular component is proportional to the mole fraction of that component in the liquid phase over the entire range of mole fractions. Note that no distinction is made between solute and solvent. The proportionality constant is the vapor pressure of the pure material. Empirically it has been found that in very dilute solutions the vapor pressure of solvent (major component) is proportional to the mole fraction X of the solvent. The proportionality constant is the vapor pressure, po, of the pure solvent. This rule is called Raoult's law: o (1) psolvent = p solvent Xsolvent for Xsolvent = 1 For a truly ideal solution, this law should apply over the entire range of compositions. However, as Xsolvent decreases, a point will generally be reached where the vapor pressure no longer follows the ideal relationship. Similarly, if we consider the solute in an ideal solution, then Eq.(1) should be valid. Experimentally, it is generally found that for dilute real solutions the following relationship is obeyed: psolute=K Xsolute for Xsolute<< 1 (2) where K is a constant but not equal to the vapor pressure of pure solute.
  • 5849622628* Electronic Calculator

    5849622628* Electronic Calculator

    UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Advanced Level THINKING SKILLS 9694/31 Paper 3 Problem Analysis and Solution May/June 2012 1 hour 30 minutes Additional Materials: Answer Booklet/Paper *5849622628* Electronic Calculator READ THESE INSTRUCTIONS FIRST If you have been given an Answer Booklet, follow the instructions on the front cover of the booklet. Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE ON ANY BARCODES. Calculators should be used where appropriate. Answer all the questions. Start each question on a new answer sheet. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 8 printed pages and 4 blank pages. IB12 06_9694_31/4RP © UCLES 2012 [Turn over 2 1 Study the information below and answer the questions. Show your working. The gold ducat is a coin currently worth 40 silver pennies, but, because of the scarcity of gold, King Offa is going to decree an increase in its value relative to the silver penny. Ethelred knows that this will be done overnight on one of the next four nights (Mon, Tue, Wed, Thu), and that the value will go up once by 1, 2, or 3 pennies. All possibilities are equally likely. Ethelred only has 30 silver pennies. He could get one or more overnight loans, but it costs a half penny to get a loan of 10 pennies from one day to the next.