Friday, 13 July 2012

By on July 13th, 2012 in lab day, science kits

10:03 – Another lab day today. As usual, I’ve saved the most obnoxious solutions for last. Stuff like concentrated acetic acid, ammonia, hydrochloric acid, and so on. Very concentrated solutions of some chemicals are called “fuming”, as in “fuming nitric acid” or “fuming sulfuric acid”. No one talks about “fuming acetic acid” or “fuming ammonia” or “fuming hydrochloric acid” because the usual concentrations already emit noxious fumes, and those fumes are sufficient to knock your socks off. That’s one major reason I decided to include 6 M solutions of those chemicals in the kits. It would actually have been easier to provide standard concentrated versions–17 M acetic acid, 15 M ammonia, and 12 M hydrochloric acid–but the 6 M solutions are usable for our purposes and the fumes are a lot less obnoxious.

I also need to start getting solutions prepared for the forensics kits. Several of those are hazardous–three or four are basically concentrated sulfuric acid with minor additions–but at least none of them are particularly obnoxious in terms of fumes.


14:05 – I just made something I didn’t know existed: iodine syrup. I was making up three liters of IKI (iodine/potassium iodide) solution that’s 0.1 molar with respect to both iodine and iodide. That meant I needed 38.07 g of iodine and 49.80 g of potassium iodide.

Now, the thing is, iodine is almost insoluble in water. But in the presence of equimolar or more iodide ions, each iodine molecule bonds with an iodide ion to form a triiodide ion, which is extremely soluble in water. But the speed of dissolution depends on the concentration of the iodide ion. If I’d simply dissolved that 49.80 g of potassium iodide in about three liters of water, added the 38.07 g of iodine, and made up the solution to three liters, the iodine would have dissolved. Eventually. It might have taken literally a month to dissolve, but it would have dissolved.

But iodine dissolves very quickly in a concentrated iodide solution, the more concentrated, the better. Potassium iodide is extremely soluble. At room temperature, that 49.80 g of potassium iodide will dissolve in about 36 mL of water. So I weighed out 49.80 g of potassium iodide in a glass 250 mL beaker, added just enough DI water to dissolve the salt, and then added 38.07 g of iodine. As far as I could tell, the iodine crystals dissolved instantly. I say as far as I could tell, because the liquid in the beaker instantly turned an opaque black, so opaque that I couldn’t see any light through the liquid even holding the beaker up against an overhead fluorescent tube and looking through the bottom of the beaker and a couple centimeters of liquid.

If there’d still been iodine crystals in the bottom of the beaker, I wouldn’t have been able to tell. I tried tilting the beaker back and forth to see if any crystals were visible on the bottom of the beaker, but there weren’t. Still, on general principles, I kept swirling the beaker for a few seconds every minute for ten minutes or so. That’s how I discovered that there is such a thing as iodine syrup. The stuff was viscous, kind of like vegetable oil. Not surprising, I guess, with almost 90 g of solids dissolved in maybe 50 mL of water.

Finally, I decided to give it go, so I carefully poured the liquid into a 1 L volumetric flask, which was the largest I have. I was kind of expecting iodine crystals to reveal themselves in the bottom of the beaker, but there weren’t any. So I made up the solution to 1.0 L and transferred it to the storage container, adding two more 1 L flasks’ worth of water. My volumetric flasks are calibrated to-contain rather than to-deliver, but I know from previous tests that the flasks actually deliver about 999+ mL. So I added just enough water to the storage container to make it up to exactly 3.0 L, give or take a mL.

24 Comments and discussion on "Friday, 13 July 2012"

  1. Chad says:

    Acetic acid is the 3-5% solution in most vinegar, right?

  2. Chuck Waggoner says:

    Yesterday, the BBC World Service officially left its home since the beginning days of radio, Bush House, which is between the Aldwych and The Strand tube stops. The World Service was—until recently—funded by the British Foreign Office, but when that ended, the BBC agreed to accept financing of the World Service. Doing so has meant massive cost cutting, including dropping 5 language services in the last 2 years, and leaving its Bush House home to join other BBC services in their buildings.

    The World Service is today a shadow of its former glory, just a decade ago. But nobody has money for anything these days, even though World Service audiences have been rising steadily for the last 30 years.

  3. Robert Bruce Thompson says:

    Yes. Standard distilled white vinegar is 5% FCC grade acetic acid.

    The stuff I’m working with is reagent-grade 99.8% acetic acid. It’s called “glacial” acetic acid, because it freezes at not much below normal room temperature. The stuff I’m supplying with the kits is 6 M acetic acid, which is roughly 32%. You really, REALLY don’t want to get a whiff of the fumes from the glacial stuff, and the 6 M stuff is no bed of roses.

  4. BGrigg says:

    I used to work in a blueprinting shop, when they used ammonia to expose treated paper. A quick pass by the machines Monday AM always cleared up any partying you had done over the weekend!

    The science kit is now physically in Canada and has been issued clearance by Canada Customs as of yesterday. That will likely be in Mississauga ON, as almost nothing in Canada gets shipped without first going through Mississauga!

  5. Robert Bruce Thompson says:

    That’s great news. Canada Customs clearing it, I mean. I didn’t have much doubt that the USPS would get it to Canada, or that Canada Post would deliver it to you once it got through customs, but I was a bit worried that the customs people would find some reason to object.

    USPS claims 6 to 10 business days to deliver, and today is day six. It sounds like it might actually get to you sometime next week.

  6. BGrigg says:

    My thought exactly. The biggest hurdle has been cleared. My experience has been 4-5 days based on other packages shipped from the US and being cleared through Ontario. I expect it as soon as Wednesday, but won’t be surprised if it’s Friday. Then we’ll see how good your packing is! 😀

  7. Lynn McGuire says:

    We are at 78 F here in Sugar land, Texas and are forecast not to hit 90 F until Tuesday. We have gotten 6 to 8 inches of rain over the last couple of days and will get more today. Amazing weather for the Gulf Coast. Usually it is 95+ F here in July with 80% humidity.

  8. Robert Bruce Thompson says:

    My thought exactly. The biggest hurdle has been cleared. My experience has been 4-5 days based on other packages shipped from the US and being cleared through Ontario. I expect it as soon as Wednesday, but won’t be surprised if it’s Friday. Then we’ll see how good your packing is! 😀

    I just got email from the USPS:

    This is a post-only message. Please do not respond.

    ROBERT B THOMPSON has requested that you receive a Track & Confirm update, as shown below.

    Track & Confirm e-mail update information provided by the U.S. Postal Service.

    Label Number: CJ16 1007 597U S

    Service Type: International Parcels

    Shipment Activity Location Date & Time
    ——————————————————————————–
    Addressee not CANADA 07/13/12 9:06am
    available – Addressee advised to pick up the item

    Arrival at Post Office CANADA 07/13/12 7:46am

    Customs clearance CANADA 07/12/12 5:25am
    processing complete

    Customs Clearance CANADA 07/11/12 2:38pm

    Processed Through Sort CANADA 07/11/12 2:38pm
    Facility

    Processed Through Sort ISC MIAMI FL (USPS) 07/08/12 10:17am
    Facility

    Arrived at Sort ISC MIAMI FL (USPS) 07/08/12 10:16am
    Facility

    Processed through USPS MIAMI FL 33112 07/07/12 4:11pm
    Sort Facility

    Processed through USPS GREENSBORO NC 27498 07/06/12 12:13am
    Sort Facility

    Depart USPS Sort GREENSBORO NC 27498 07/05/12
    Facility

    Processed through USPS GREENSBORO NC 27498 07/05/12 7:51pm
    Sort Facility

    Dispatched to Sort WINSTON SALEM NC 27105 07/05/12 4:15pm
    Facility

    Acceptance WINSTON SALEM NC 27106 07/05/12 3:32pm

    Electronic Shipping 07/05/12
    Info Received

  9. BGrigg says:

    Yes! I got that just a few minutes ago myself. This has proven to be the fastest shipment I’ve received from the States.

    I dared to mow my lawn this morning, and they must have come by at the same time. When I saw the notice on the door, I thought it was for some books I ordered from Amazon about a week ago, though they usually just leave those on the porch. Alas, I can’t pick up the kit until after 2PM my time. I will report on the condition of the kit at that time.

    I posted earlier after receiving the track and confirm notice about the customs clearance. I have NEVER received a package the very next day after clearing customs with the post office.

  10. OFD says:

    They jus’ testin’ you boyz, see who pick up dat package. Fittings for new orange jump suits being made shortly.

    Can youse read Arabic?

  11. BGrigg says:

    I’ll send in my eldest, he looks like me.

  12. SteveF says:

    My volumetric flasks are calibrated to-contain rather than to-deliver

    What’s the difference? Meniscus? A small amount of fluid left behind when you pour?

  13. Robert Bruce Thompson says:

    To-contain is how much a volumetric container holds when filled to the index mark. To-deliver is how much it delivers when you empty it. As you speculated, the difference is due to a minor amount of liquid that remains in the container, coating the inside surface.

  14. Robert Bruce Thompson says:

    Yes! I got that just a few minutes ago myself. This has proven to be the fastest shipment I’ve received from the States.

    I dared to mow my lawn this morning, and they must have come by at the same time. When I saw the notice on the door, I thought it was for some books I ordered from Amazon about a week ago, though they usually just leave those on the porch. Alas, I can’t pick up the kit until after 2PM my time. I will report on the condition of the kit at that time.

    That’ll teach you to mow your lawn instead of having your son do it.

    I hope the kit arrived undamaged. It should have. I shipped it inside the regular regional-rate box that I usually use for shipping, and put that box inside a flat-rate box. I hope two layers of box protected it.

    I posted earlier after receiving the track and confirm notice about the customs clearance. I have NEVER received a package the very next day after clearing customs with the post office.

  15. OFD says:

    I mowed lawns from an early age, and having done ours, moved on to do the neighbors’ lawns for money. Same deal in the winter with shoveling driveways. And my ten-year-old nephew down in the Peoples’ Republik of Taxachusetts regularly does their lawn. I got five bucks for lawns and driveways, and this was back in the Glorious Sixties. Not bad money in them daze.

    Also delivered papers, worked stocking shelves at the Stop & Shop and retrieving carriages from the vast acres of parking lots in the dead of what used to be winters down there. And worked part-time as a commissioned young men’s department clothing salesman at the Jordan Marsh in high school. Oh, and usher at two different cinemas. All while in school, on teams, working on models, my stamp and coin collections, and blowing shit up.

    Later I sold drugs. While still doing most of that other stuff. And getting on the Honor Roll at school and doing AP English and American History classes.

    Damn kidz nowadays….

  16. BGrigg says:

    Both kids were at work, and I’m currently play acting at being retired, so…

    When I meant 2PM, I meant 2PM Saturday!

  17. Miles_Teg says:

    Bill wrote:

    “I dared to mow my lawn this morning…”

    That’s what the kids are for, isn’t it?

  18. Miles_Teg says:

    Bill wrote:

    “I’ll send in my eldest, he looks like me.”

    Bill, you’re kidding yourself. You don’t have ANYTHING LIKE as much hair as your sons.

  19. SteveF says:

    Maybe he can do a comb-over with the ear hair.

  20. Miles_Teg says:

    OFD wrote:

    “Later I sold drugs. While still doing most of that other stuff. And getting on the Honor Roll at school and doing AP English and American History classes. ”

    You worked in a pharmacy? I didn’t know that… 🙂

    Tell us about your AP Maths, AP Physics and AP Cookery^H^H^H^H^H^H^HChemistry results.

    I did American History in my matric year, got an A. Got into Adelaide University. My Year 12 chemistry teacher couldn’t believe I’d passed his subject.

  21. Miles_Teg says:

    Steve F wrote:

    “Maybe he can do a comb-over with the ear hair.”

    There used to be an older guy on my bus to/from work who had, what do you call it?, a bouffant hair style. He must have been 10 years or more older than me but he had LOTS of hair. LOTS. And it was all brown. Not a trace of grey. I often wondered if he’d stolen a bunch of Gary Glitter’s wigs. It looked so absurd. Grey hair looks really distinguished in my opinion, so I think people at that age should just let it happen.

  22. SteveF says:

    I didn’t catch it the first time, but OFD took AP courses. This pisses me off because OFD is close to ten years older than I, but my high school didn’t offer AP courses, that I recall. That’s why I dropped out and went to college instead of senior year.

    (I wanted to go early-admit to the local college because the high school had nothing left for me, but the principal, Art Batty, was an assinine control freak and wouldn’t allow it despite pressure from my mom, the school board, and some of the college’s administrators. So I dropped out. And then found that the drop-out paperwork was “disappeared” and I was considered an early admit student after all. I assume the stinkberry caved in for the state aid money. If I were the cynical and somewhat-less-naive bastard I am now, I’d have raised a stink about him tampering with the paperwork, but I didn’t.)

  23. Miles_Teg says:

    Hmmm. I understand about 0.2% of what I hear about the American education system. Jerry P has an interesting comment about it.

  24. OFD says:

    “Tell us about your AP Maths, AP Physics and AP Cookery^H^H^H^H^H^H^HChemistry results.”

    Uh, that didn’t happen. I barely passed Algebra I, and that only after taking it over again, plus having to do it a third time during the summer session, which was brutal. Had “Earth Science” which I didn’t do that great in, and Biology, which I liked and did well. That was the extent of my STEM in high school.

    But I took AP English courses throughout and two years of AP American History, plus every “social science” course the school offered at that time, including economics, psychology, sociology, Russian studies, international relations, etc. Earlier I’d had wood and metal shop and darkroom photography, plus music. I also read my ass off and actually did extra-credit papers regularly for my history classes.

    The national publik skook system was/is a total hodge-podge of different ideologies, controls, processes, and political chicanery, all subsumed under the philosophical bases of Dewey, Mann, and Marx. So we’ve had such widely disparate experiences as those of SteveF, myself (my high school was/is twenty miles west of Boston and we traveled to Beantown regularly for official school trips and also my own and buddies’ extracurricular activities), and inner-city minorities, who may as well have been going to school in the Congo or Sumatra.

    It should be totally dismantled forthwith and there are a variety of very interesting alternatives, many of them either discussed here, or actually put into practice by our host, many blessings be upon him and Barbara accordingly. They walk the walk.

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