• Re: Metal to resist Cl medium

    Updated: 2010-09-02 20:29:38
    it would be necessary to know if the gas is "dry" or "wet", if it's dry then it can be handled with carbon steel or stainless steel if it's wet you need an higher alloy nickel alloys, have a look at this paper from NIDI on material selection for chlorine services:http://www.stainless-steel-world.net/pdf/10020.pdfhope this helpVitt

  • Biochem

    Updated: 2010-09-02 20:24:35
    Can I post Biochem questions on here? If not, can someone give me a helpful website please?thanks, Mandy

  • Re: Cu + Al problem

    Updated: 2010-09-02 20:23:53
    are the two materials in direct contact? if they are not then is not possible to have Galvanic Corrosion. in they are then based on the galvanic series of metals  aluminum should be the metal that corrodes, even if in distilled water with low conducibility galvanic corrosion will be limited and also if it's a closed loop then the oxygen should be depleted and corrosion should stop.Vitt

  • Re: Thermodynamics

    Updated: 2010-09-02 19:51:53
    First of all energy changes happen at a molecular level (they are caused by the breaking of some bonds and the forming of others: reaction enthalpies can be roughly evaluated calculating the changes in bond energy) so the energy is taken from (or given to) the solution itself. Obviously the reaction can be exothermic enough to cause the heating of the surroundings too (try to mix NaOH and vinegar in a bowl and you'll feel the heat released) but this is simply caused by the conduction of a part of the energy released through the container.

  • Re: Phase of the pentane?

    Updated: 2010-09-02 19:32:05
    Phase changes happen when the vapor pressure (in this case that of the liquid pentane) is equal to the external pressure. You know that pentane is liquid at 293 K and atmospheric pressure... (pvap<patm) how does vapor pressure change when temperature increases?

  • Cutting-Edge C&EN Webinars, Coming Soon

    Updated: 2010-08-31 20:45:00
    The program of C&EN Webinars on cutting-edge research topics continues to broaden; you can register now for any of these upcoming sessions: Core Technologies for Chiral & Specialty Intermediates for Pharma (Thursday, September 9, 10:00 a.m. EDT); Hopscotch and Jump Rope - get lead hops, scaffold hops, and step-jumps in potency, with unique computational strategies for molecular design (Thursday, September 16, 11:00 a.m. EDT); or Stabilized Lithium Metal Powder (SLMP): A New Approach for Energy Storage and Other Applications (Thursday, September 23, 9:00 a.m. EDT).

  • ACS Careers Job Club Webinars

    Updated: 2010-08-31 20:45:00
    Log In ACS Journals C EN CAS ACS Network Store Governance About Us Contact Publications Meetings Careers Membership Networks Education Policy Funding Awards Press Room American Chemical Society Careers Job Search Starting a Job Club Job Clubs Provide Support for Your Job Search Job Clubs Provide Support for Your Job Search If You Can’t Find One That’s Right for You , Start Your Own Misery Loves Company An informative article on Job Clubs by an ACS . expert Other Job Club : Resources Job Club Webinar Series Job Search Strategies Webinar wmv file 53 MB Preparing Your Resume Webinar wmv file 59 MB Effective Interviewing Webinar wmv file 52 MB ACS Career Series Videos Planning My Job Search wmv file 67 MB The Group Discussion Guide Facilitators Discussion Guide Resumes wmv file 58 MB The Group

  • O Level Chemistry: Molecular & Empirical Formulae

    Updated: 2010-08-31 05:30:34
    For all students learning O Levels Chemistry (and other equivalents), it is important that you understand the difference between the 3 types of formulae commonly used – namely Molecular Formula, Empirical Formula and Structural Formula. Previously, we have discussed on this topic before. You can find them HERE. Let’s define them now, for better understanding and application: Molecular [...]

  • O Level Chemistry: Air (Atmosphere)

    Updated: 2010-08-24 02:47:56
    Air or some like to call it Atmosphere is considered a ‘minor’ chapter in GCE O Levels Chemistry examination, so much so that many teachers do not emphasise on their existence, not to mention importance. As described by my Sec 4 Chemistry students, many of their Chemistry School teachers: Ask the students to read textbook on their [...]

  • O Level Chemistry: Mole Calculation Question & Common Mistakes Made

    Updated: 2010-08-22 03:30:33
    The following Mole Calculation question is not difficult but many O Levels Chemistry students tends to make mistake in exams, where time is not a luxury. When the same question was posed to my regular classes of Sec 3 and 4 O Levels and IP students, i realised that many fall into the trap also. Let’s [...]

  • O Level Chemistry: Challenging Mole Calculation / Electrolysis Questions

    Updated: 2010-08-14 01:29:34
    In the previous post, we have discussed on a MCQ question on Electrolysis that requires students to: 1. Write out discharge half equations 2. Do Molar Ratio Comparisons Question: Which of the following requires the least  number of eletrons for discharge? A. 2 mol of Al3+ (aluminium) ions B. 5 mole of OH- (hydroxides) ions C. 3 mol of O2- (oxides) ions D. [...]

  • O Level Chemistry: Challenging Mole Calculation / Electrolysis Questions

    Updated: 2010-08-12 06:28:27
    In the previous post, we have discussed on 1 MCQ question on Electrolysis that requires basic Mole Calculations strategy to solve. Do note that Electrolysis topic is only applicable to students taking: GCE ”O” Level Pure Chemistry (Code: 5072) Integrated Programme (IP) – it will be classified under Electrochemistry chapter IB programme IGCSE and other equivalents It is NOT applicable to [...]

  • (Visible) scars of chemistry

    Updated: 2010-08-02 06:03:48
    Mitch’s post showing the video of “the mark of the chemist” reminds me of one of the most visible remembrances I have of graduate school: the scar on one of my middle fingers (see left.) On a lovely Saturday in the lab (my music playing, no one else around), I dropped a Dewar flask from [...]

  • Dangerous Chemistry Sets

    Updated: 2010-07-26 23:23:02
    From: SMBC – Fear Itself ~Mitch

  • Cargo cult science in the Gulf, news at 11

    Updated: 2010-07-21 06:34:32
    The Gulf oil tragedy has already shown the ignorance of some reporters about chemistry. However, a Mobile TV station and their chemist has taken it to new heights when they blamed the oil spill for (likely) bad glassware. WKRG is a local TV news station in Mobile, Alabama; they sent intrepid reporter Jessica Taloney to [...]

  • Common Student Difficulties in Organic Chemistry

    Updated: 2010-07-13 15:51:43
    While cleaning out my newly assigned “war room” (the setting where I’ll strategize on how best to torture students this fall), I came across some fairly interesting documents that were buried in far corners of crowded file cabinets.  They’re nothing personal or discriminating (sorry TMZ), but I saw them as material I could use in [...]

  • Chemists Purposely Withholding Information

    Updated: 2010-07-09 16:57:23
    I once saw an undergraduate setting up a reflux in my lab, and I could tell immediately it wasn’t going to work. The undergraduate didn’t take enough precautions to ensure that the liquid wouldn’t leak out from the joint connecting the round bottom flask and the condenser. I debated whether I should say anything, but [...]

  • Your Academic Lineage

    Updated: 2010-07-05 16:45:30
    Over dinner the other night, my uncle and I started comparing and contrasting our academic experiences.  He’s a fascinating person who earned a bachelor’s degree in computer science in the late 1970’s. After discussing the finer points of Moore’s Law, and how he agonized over purchasing a 20 MB hard drive in the 1980’s for [...]

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