Thursday, 4 September 2014

By on September 4th, 2014 in lab day, personal, science kits

08:08 – Being a chemistry geek, I get excited about things that other people don’t even notice. For example, yesterday I was making up solutions for kits. One of the solutions I made up was the IKI (iodine/potassium iodide) solution (Lugol’s solution) that’s included in most of our kits.

Iodine is extremely insoluble in water, something like 290 mg/L (290 ppm) at room temperature. Potassium iodide, on the other hand, is extremely soluble in water, something like 1,400 g/L at room temperature, or almost 5,000 times more soluble than iodine. The interesting thing is that iodine is very freely soluble in solutions of iodide ions, and the more concentrated the iodide solution, the faster the iodine goes into solution.

In the past, I’ve made up two liters of IKI solution by dissolving 40 grams of potassium iodine (KI) in about 400 mL of water, adding 25.4 grams of crystal iodine, swirling the bottle periodically over the day or so that it takes the iodine to go into solution, and then making up the solution to two liters. Yesterday, I decided to see if I could speed things up a bit by using much less water initially.

So weighed out 40 g of KI and transferred it to a 125 mL bottle. Ordinarily I’d have added some water at that point to dissolve the KI, but instead I weighed out 25.4 g of iodine crystals and added them to the bottle, right on top of the solid KI. Before I had time to add any water, a reaction started. A solid-state reaction, in which the solid molecular iodine started to react with the solid potassium iodide, producing essentially potassium tri-iodide in solid form. I could actually watch the reaction progress, starting with a bottom white layer of KI and a top dark-gray layer of iodine crystals. The two layers began to merge into a single dark brown layer.

I watched that happening for a few seconds and then added 60 mL of so of distilled water and capped the bottle. I inverted the bottle several times to mix the contents and all of the solids went into solution almost instantly. Because dissolution of KI is endothermic, the bottle quickly became quite cold. Even though the air in the house is air conditioned and dehumidified, water vapor immediately started condensing on the surface of the bottle and running down the sides. This whole process is fascinating in so many ways: kinetically, thermodynamically, and enthalpically. It’s good to be a geek.


11:55 – A few years ago, Barbara literally knocked over a hornets’ nest while she was working in the back yard. She was stung badly, and she’s understandably afraid of hornets and similar stinging insects. A week or so ago, she mentioned that there was a nest of yellow jackets or hornets down at the back of our property, apparently inside the trunk of a tree. So I walked down there after dark that evening and took along a can of hornet/wasp killer. One of those that shoots a stream instead of a fine mist. I walked over to where I’d seen the bugs clustering earlier that day, and hosed it down with the hornet/wasp killer. They immediately swarmed out of the nest, but I turned off my flashlight and walked away unstung. The next day, I noticed there were a lot of dead bodies lying near the nest entrance, but there were still a lot of them swarming around. So I went down again that night and sprayed again. The next day, same deal. I got some of them but there are a lot left. I understand that nest may be buried deeply and contain literally thousands of the things.

If I were living in an Agatha Christie novel, I’d use something that actually kills them, like potassium cyanide. A couple tablespoons of that in the nest entrance and a bit of sulfuric acid would fumigate the hell out of that next. I have both of those in my lab, but I think I’ll take a more traditional approach.

I search the web for stinging insects in North Carolina, attempting to identify the species, but I haven’t gotten a close enough look at one to be sure. There are several candidates, and the advice for all of them on the NC Ag Extension web site is similar. First, just leave them alone unless they present a real threat to people. Second, if you have to kill them use something like the Spectrocide/Hot Shot insect spray I used, following the label directions strictly, of course. But the site warns that it probably won’t be effective and even several treatments may leave a viable nest. It does say that the colony dies out in the winter and is seldom re-used the next year.

The site also says whatever you do, don’t use gasoline because it’s harmful to the environment. I take that to mean that gasoline will in fact kill all of the little SOBs but using it would violate federal law. Federal law, of course, ignores the fact that these stinging insects are very harmful to our environment. I’m thinking napalm.

28 Comments and discussion on "Thursday, 4 September 2014"

  1. Lynn McGuire says:

    Like mosquitoes, I am fairly sure that we could eradicate wasps without any damage to the environment. Or maybe not, I’m no bio dude.

    I have gone through six cans of Hot Shot in the last month trying to eradicate nests in the front entrance to our office. It is over 20 ft tall at the peak and tough to get the spray up that far. The survivors just keep on building new nests around the entrance. I bought four more cans last night.

    My derm doc came through and prescribed my doxycycline meds yesterday. I had forgotten that doxycycline interacts with warfarin and makes it less effective. So, I have to take more warfarin daily (8.0 mg/day right now). Without the doxycycline, I would had to reset my warfarin again. And, I just got through resetting my warfarin from starting Rythmol three months ago which also interferes with warfarin and makes it more effective. Argh!

  2. Lynn McGuire says:

    BTW, my rule of thumb on wasps is, dirt dobber nests, no worries. Paper nests, watch out! And red wasps are the worst of all being aggressive and multiple stingers.

  3. Lynn McGuire says:

    I am back to looking at our model of CO2 absorption by an aqueous mixture of Diglycolamine at 940 psia and 120 F to 200 F. Sigh. Some days it sucks to be geek.

  4. Robert Bruce Thompson says:

    Huh. I didn’t realize that aqueous amines were still used to scrub CO2 and H2S from sour gas. I figured it’d all be membrane technology by now.

  5. Lynn McGuire says:

    Huh. I didn’t realize that aqueous amines were still used to scrub CO2 and H2S from sour gas. I figured it’d all be membrane technology by now.

    Membranes only work for low concentrations, less than 1% of H2S and less than X% (not sure) of CO2. And the membranes do not like heat (middle east). And the flowrate that we work with is very high, 100 to 2,000 million SCF/day. Aqueous amines are way cheaper than membranes, even with the regeneration cost.

  6. R says:

    Lately I’ve been finding the foaming wasp spray more effective. If you are out to buy a second can I’d suggest getting the foaming spray.

  7. Chad says:

    I’ve seen a huge increase in the number of Red Velvet Ants on my property. I used to think they were some rare species of ant and so let them be, but I’ve learned they’re actually a wasp with a notoriously painful sting (hence their other name “cow killer”). Luckily, the females are wingless so it’s easy enough to stomp on them.

  8. OFD says:

    I got stung up and down myself when I was a little kid by a swarm of hornets; my grandma made a paste of baking soda and water and layered it on me and I was fine. I had run screaming into the house while the bastards chased me. They don’t scare me none, though; we have a couple of the small paper nests up under the eaves here but they don’t bother us.

    For Dr. Bob’s situation I’d go with the napalm solution; I am quite sure he can mix up a fine batch of it.

    We don’t have much of a bug problem around here; black flies during season and brown deer flies, likewise, but haven’t seen any in this location yet. Occasional skeeters and fleas, wiped out by the Raid.

    They kept me hoppin’ today at work but I managed to fix just about everything anyway. I love how when you fix something you never hear from them if it worked OK, ya gotta go check on it. To be fair, a couple of them do thank me, so I’ll make sure to take care of them from now on. See how it works, lusers? Also, tell me EXACTLY what the issue is, not “Sumthin’s wrong with the printer” and “We have one computer down and it’s not printing and if the other one goes it could halt production…” When what he meant was that there was a little printing glitch, easily fixed by making the buggers use Firefox instead of Chrome to print out their labels. Not the first time with this character, and the kids had told me he was knowledgeable.

    Gotta hand it, though, to the girl in Shipping; she’s a plugger; claims to know zip about computers but installed the UPS and FedX stuff herself and tried to do as much as possible anyway without me having to mess with it more than the ten hours or so I’ve already spent on it. 31 years old, divorced, ex in jail, two boys to raise, and they’re foreclosing on her house. While she works her butt off at that place. People like that I’ll go the extra mile for.

  9. Roy Harvey says:

    Like mosquitoes, I am fairly sure that we could eradicate wasps without any damage to the environment. Or maybe not, I’m no bio dude.

    From the Wikipedia entry for Wasps.

    A wasp is any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant.[1] Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their numbers, or natural biocontrol. Parasitic wasps are increasingly used in agricultural pest control as they prey mostly on pest insects and have little impact on crops.

  10. Lynn McGuire says:

    Ok, my day is going weird. Am exchanging emails with a prospect in the USA containing the words radionuclides and radiological. This is how I got visits from the CIA and FBI fifteen years ago concerning a customer in India.

  11. Lynn McGuire says:

    BTW, Sean Hannity was noting on his radio show today that several of his friends are planning on having gas tanks full and doing some prepping before Sept 11 next week.

  12. Lynn McGuire says:

    Gotta hand it, though, to the girl in Shipping; she’s a plugger; claims to know zip about computers but installed the UPS and FedX stuff herself and tried to do as much as possible anyway without me having to mess with it more than the ten hours or so I’ve already spent on it. 31 years old, divorced, ex in jail, two boys to raise, and they’re foreclosing on her house. While she works her butt off at that place. People like that I’ll go the extra mile for.

    That is why I love living in the USA. Lots of good people like her around the place. Sad about her ex, I’ll bet drugs of some sort. I hate the War on Some Drugs ™.

  13. OFD says:

    I’ve spoken with two single mothers raising children recently, one at work and one at the grocery store, and both said the ex’s were loser assholes and they’d made a bad mistake getting hooked up with them. That’s their side, of course, but they don’t strike me as being liars and bullshit artists. They have a tough row to hoe and keep their sense of humor and nose to the grindstone regardless and clearly love their kids, who I hope are not loser assholes like their dads.

    Yeah, probably dope busts; either pot, which is totally ridiculous, or the harder stuff floating around up here, oxy, meth,heroin, etc. I hate that War and also the War on Some Terrorists.

    And am constantly thrilled, all my life so fah, or most of it, by the fact that our former enemies are now our buds and vice-versa.

    ‘sposed to be hot and humid next few days here, so I will spend a good chunk of the next 48 hours inside the A-C. Local country station down in the bustling metropolis of Johnson, VT had the Old Farmer’s Almanac editor on there this morning and she confirmed Mr. Lynn’s prediction of a VERY cold wintuh but only moderate snow; snow on T-Day and a white Xmas, she said. So get the wood and the oil supplies all organized, etc., my main project over the next few weeks.

    Mrs. OFD is in Point Arena, Kalifornia this week and sez the terrain inland is a dried-out mummified wasteland, thanks to the ongoing 100-Year Drought, all brown and awful-looking. She’ll be in Orange, Kalifornia, next week, and Syracuse, NY, the week after that and then home for a week.

    No, we don’t get wottuh bills here.

  14. Don Armstrong says:

    Bob, I’ve got a couple of thoughts on your wasp situation. Both of them are in the “flailing about and seeing if it worked” category, but still that can be fun.

    One is fumigating with plain old sulphur smoke (or in your case, I’d be prepared to allow “sulfur”). If most everything needed is below the entrance, this works well. A little tuna tin, a hole in the side, a little sulphur, light, tilt tin and jam tin hole against/into wasps hole. Due care against accidental incineration of incidental elements. Certainly works with rats, rabbits, and random rodents; and brewers, vintners and apiarists use it successfully; but in suburbia you’d need to exercise a certain amount of care to ensure that most all of it went into the hole, and hardly any into the surroundings.

    The other possibility is just to chock up the hole in the tree with epoxy cement or Stockholm tar or cement or plaster of Paris or something else relatively impervious, and call it done. Leave the little bastids to their own company. Sometimes they have an emergency entrance, and this approach has the advantage of forcing them to reveal any such while they still have enough numbers to show it up, and you’re ready for it.

  15. OFD says:

    I hereby endorse, first, sulphur; then napalm; followed up by cement.

    Then we shall expand the program to eliminate the pestilence and vermin in Mordor.

  16. SteveF says:

    Napalm is for candy-asses. Thermite that sum-bitch!

  17. Robert Bruce Thompson says:

    Well, I do have thermite as well…

  18. Ray Thompson says:

    terrain inland is a dried-out mummified wasteland

    As far as I am concerned that describes ALL of southern California and a good chunk of the northern area.

  19. I don’t know quite why I first sprayed a yellowjacket nest with 1,1,1-trichloroethane — it was sort of one of those random things one tries as a young man, usually with adverse consequences — but the plopping noise of instantly-dead yellowjackets hitting the ground made it clear that this one Worked with a capital W. Later I learned that others also used on wasp nests. Unfortunately the stuff is not available any more (for ozone layer reasons); trichloroethylene works too, but not as well. (It’s sold in stores as brake parts cleaner, in a spray can.)

    There’s also fipronil:

    http://yarchive.net/house/fipronil.html

  20. MrAtoz says:

    And just to be raaaacist, the rabble rousing fast food workers being arrested for civil disobedience appear to be 99% Black and 1% Hispanic. The Caucazoids I see are probably libturds with SUVs parked around the corner.

  21. MrAtoz says:

    Ugh! Romney hinting about 2016. I’m voting for Hildebeest to finish the country off. Fauxahontas for VP.

  22. jim cooley says:

    I never knew brake cleaner was tric, that’s cool. Love the stuff.
    Any suggestions for killing bed-bugs? (Am in India; and no, you don’t want to know the details…)

    My uncle once made some yellow jacket traps and discovered that liverwurst was a great attractant.

    Final bit of trivia I came across yesterday: diabetes triples the risk of contracting active TB.

  23. Don Armstrong says:

    “Any suggestions for killing bed-bugs?”

    In my limited experience of what worked, and backed up by searching now:

    Heat! Hot wash, hot dry clothes, bedding, fabric.
    For what can’t take heat, wash in miticides (e.g. flea-wash cat and dog soap, lice shampoo), then leave it to work, then extended drying, then wash the poison out and dry again.

    Before and after treatment, isolate in double layers of air-tight bags that either will also be washed, or else discarded.

    Always remember there are eggs that will hatch after treatment of living active bugs. You WILL need to repeat treatment at least twice and probably thrice to ensure eradication.

    If you must stay in infected areas, bag bedding in plastic, treat inside with miticide, sleep on sealed plastic to avoid or cut down on re-infection. Every seam, join, timber butting together, any paper-thick crevice WILL shelter bugs.

    RUN AWAY. It takes a COMPETENT professional to ensure that bedbugs are eradicated.

    That’s as far as my experience carries me. If you can’t abandon things for the professionals, find a really REALLY REALLY competent one, and ask their advice.

    Failing all else, and with professionals not an option, then once you’ve stripped out everything you can treat as above, then lots of sulphur smoke, of course. Note that this stuff is acrid, poisonous, and extremely noticeable. Be careful about use around people. Confine the smoke in furniture by closing doors and drawers, and by sealing in plastic.

    Use highly aromatic organic material to discourage re-infection. Where you are, neem would be one option; plus any highly aromatic herbs that aren’t unbearable for you and your companions to stand being around. Sage, bay, thyme, rosemary, mint, pine, lavender, cloves, eucalyptus, ti-tree, oregano or marjoram, fennel, anise, sandalwood, cedar, camphor, wormwood, et cet era, et cet era, et ct era. Camphor=moth-balls, unpleasant but concentrated and cheap. CAREFUL: highly aromatic may also mean highly allergenic and/or poisonous.

    Diatomaceous earth (tiny fossil diatom silicon skeletons, multi-spiked spear balls to pierce and dehydrate arthropod exoskeletons) spread to kill anything that comes around. Also used for food additive, to kill pest infestatons. NOT the same as used for filters. Investigate thoroughly – people will sell you anything, whether or not they know it’s not what you need. I’d be careful here. I haven’t heard anything bad (and I’ve been looking), but it sounds like it has potential to damage lungs if inhaled.

  24. brad says:

    The war on some terrorist

    Gah. Everyone is now arguing for sending weapons into the Middle East and giving them to anyone who claims to be against ISIS, and the US (can y’all confirm this?) is apparently thinking about sending troops again…

    I know that no one learns from history, but this is ridiculous, seeing as it’s only a few years since the US created this problem by sending troops and equipment to the Middle East. Even very specifically to Al Queda, because they were supposedly the “moderates” in Syria. Now that Al Queda has been absorbed into ISIS, the Iraqi equipment has also fallen into their hands, somehow the solution is to send even more free weaponry to today’s supposed “moderates”?

  25. Jim Cooley says:

    Thanks Don. Diatomaceous earth sounds pretty clever, but probably pretty hard to come by in tinytown Thrissur. I wonder if jeweller’s rouge would work? IIRC mechanism of action is by clogging their little spiracles. I can prolly get that. Not a big deal as I’m not allergic at all — they are just unaesthetic. And I take special care to isolate laundry and luggage when I reach more civilised climes. Norman’s Frontline solution to the wasp’s nest was a neat idea; can we ship some to Washington?

  26. ech says:

    If there are any swimming pools in town, look for DE at the supply stores. (Long shot, I know.)

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