Tuesday, 19 February 2013

By on February 19th, 2013 in lab day

08:50 – Sometimes I do really moronic things. Yesterday, I was making up two liters of the nitrogen-free Fertilizer C concentrate for the biology kits. That solution contains trace amounts of boron and cobalt, but the primary chemical is 194 grams of calcium acetate monohydrate.

So I went to the chemical stock shelves where I found a 500 g bottle of reagent-grade calcium acetate monohydrate. The only problem was that it had only a few grams of the chemical left in it. Rats. Normally, I reorder when I get short on something, but in this case I’d apparently forgotten. Either that, or I have a new bottle somewhere that I don’t remember. Oh, well.

But I had plenty of glacial acetic acid and calcium hydroxide on hand, and it’s easy enough to synthesize calcium acetate by reacting those two chemicals. One mole of calcium hydroxide reacts with two moles of acetic acid to form one mole of calcium acetate and one mole of water. Simple enough, and it doesn’t even foam as calcium carbonate would.

So I calculated the equivalent masses. The 193 grams of calcium acetate I needed was 1.10 moles, which corresponds to about 81.5 grams of calcium hydroxide. I then calculated the amount of glacial acetic acid I needed. The molar mass of acetic acid is 60.05 g/mol and its density is 1.049 g/mL, which means 1.10 moles would be 66.06 grams or 62.97 mL. But my reagent-grade acetic acid assays at 99%, so I divided those values by 0.99 and weighed out 66.73 g of acetic acid.

Calcium acetate is unusual in that it exhibits retrograde solubility. That is, it’s less soluble in hot water than in cold. I checked the solubility at room temperature and decided to dilute the acid aliquot to about 600 mL to provide enough water for the calcium acetate to dissolve. I then added the dilute acid to the calcium hydroxide, expecting the powder to disappear relatively quickly as it reacted with the acid.

Calcium hydroxide is only very slightly soluble in water, so as I swirled the slurry I wasn’t surprised to see a lot of suspended solids. I was surprised that the solids settled out on the bottom of the vessel, showing no sign of disappearing. Anhydrous calcium acetate is essentially odorless, but the more common monohydrate form and calcium acetate solutions have a very distinct odor. It’s not at all unpleasant, and has a slight undertone of vinegar that’s caused by the calcium acetate hydrolyzing to calcium hydroxide and acetic acid. So I sniffed the reaction vessel and detected a strong odor of calcium acetate but no vinegar odor at all. You’d think that’d have given me a clue, but no. I decided that the reaction might be slower than I’d expected, so I decided to give it a while to finish reacting.

It finally hit me. Duh. One mole of calcium hydroxide reacts stoichiometricly with two moles of acetic acid, not the one mole I’d added. So I added another 67 g of glacial acetic acid and swirled the reaction vessel. Sure enough, nearly all the solids disappeared, but after standing there was still no odor of vinegar. So I added a few extra mL of acetic acid, just in case. It’s not like a bit of extra acetic acid will harm anything. We supply this concentrate in 15 mL bottles. Diluting 125 mL of part A, 30 mL of part B, and 15 mL of part C yields 12.5 liters of nitrogen-free fertilizer working solution, so this concentrate ends up being diluted with more than 800 parts water.


13:50 – I now have all of the solutions made up for biology kits. Except for the ones for which I was short of chemicals–I have enough for at least 60 bottles of each of those–I made up enough for 120 or more kits, which should hold us for a while. Now to start filling bottles.

13 Comments and discussion on "Tuesday, 19 February 2013"

  1. brad says:

    I just had a hilarious customer service experience. I was putting out a software project for bids, and thought I would also drop an inquiry by a broker – an Internet company that claims to match customers with appropriate software vendors.

    That was back in mid-December. Today, more than two months later, I get a completely generic email thanking me for my inquiry and explaining how they have been trying to “reach out” to me without success. Dunno how, since email has been working just fine for the past two months, as has my telephone, the postal service, the fax machine, and probably the carrier pigeons.

    Doesn’t really matter, it was just a thought. I also contacted vendors directly, and we are already in the final selection phase. What struck me as hilarious was the phrase “reach out”. Has valley-girl dialect become mainstream? Do you guys “reach out” to your customers, or do you just contact them?

  2. Robert Bruce Thompson says:

    I can honestly say that I have never reached out for a customer. I have emailed them, snail-mailed them, telephoned them, and so on, but somehow I never got around to reaching out. Anyway, is that illegal in some states?

  3. brad says:

    On a completely different topic, I got a letter from our bank last week, just a couple of days before Switzerland signed the FATCA agreement. The bank apparently knew this was coming. The letter informs me that I am supposed to sign an agreement:

    – to allow the bank to send all our personal financial information to the IRS, as well as to “third parties”.

    – to assume full responsibility and liability for any misuse of the data.

    – to relinquish my privacy rights under Swiss law and accept the laws of the USA “and other countries”.

    If I don’t, they will cancel our accounts.

    I went to another bank today, explained the situation, and pointed out that as of April, I will no longer be a US citizen. The answer? It doesn’t matter. They are very sorry, but they do not dare take any new business from anyone even vaguely associated with the USA. Having been born there is sufficient. No one is saying what blackmail the US is using to inspire this level of fear, but it must be impressive (and almost certainly extralegal).

    I’ve sent the details to our lawyer, asking for advice. Also to one of the major newspapers, in hopes they might be interested. I certainly will not sign such a ridiculous agreement, so the next few weeks promise to be interesting…

    (Hope this doesn’t appear twice: the first attempt at posting seems to have failed)

  4. OFD says:

    I couldn’t connect to the site here at all for about an hour earlier, right as I was trying to post something.

    Brad’s experience, even living over there in Switzerland, is instructive. Our regime has apparently decided to run the solar system all by itself and will brook no nonsense from any malcontents or dissidents. I’ve seen this sort of situation described elsewhere, and ex-pats are choosing places other than Europe to set up housekeeping, like Chile, Paraguay and Singapore. The Euros are caving left and right to whatever our overlords and masters decree. I note, however, that the Russians, Chinese, Iranians and North Koreans are not thus far so malleable. The little panda guy in NK has just successfully been large and in charge while they set off a nuke AND an ICBM, thus giving them, potentially, the ability to hit us over here, and they don’t like us very much, either. Maybe we could bring our people home once and for all from the DMZ and let the South Koreans handle their own defense finally? I mean, why poke a stick into the panda’s cage?

    That would probably do the trick. If not, and they light one over on us, we can then obliterate that half of the peninsula and put a few million people out of their utter misery.

  5. Robert Bruce Thompson says:

    The site has been up and down, mostly down it seems, for several hours. I’m not sure what’s going on, but I’ve emailed Dreamhost tech support to ask them to fix it.

  6. Chuck W says:

    Yeah, I could not get in at all last night, but this is the first I have tried today. As a kid, the older people in my family thought it quite likely that we would be bombed. In fact, I had lunch with somebody today, who told the story of his grandfather (WWI vet) who tried to convince his aunt (grandfather’s daughter) not to live anywhere near Cleveland, where she had recently gotten a job after getting a degree from Case-Western, because he believed Cleveland, as a military manufacturing center, would be one of the first to be bombed as WWII was developing.

    I do believe the day is coming when we will be bombed by something. Like 9-11, it will come out-of-the-blue with no advance warning, and wherever it hits, we will be totally unprepared for it. I have mentioned here before that at a visit to Hilter’s science research institute in Penemunde, where von Braun learned how to steer rockets, they had monthly reports (in German) sitting out for visitors to read. During the late ’30’s, their goal as outlined in the reports was to build a rocket to be launched from within Germany, that would deliver a warhead to New York City. They never came close to achieving that kind of distance and ran out of money to continue the project after about 1940, but any number of countries in the Mid-East could now do it, as could N. Korea.

  7. Chuck W says:

    Okay, you all know that very opening riff on “Revolution” by the Beatles, right? From around 1968. I’ll let you google a YouTube video of it, if your memory is failing.

    Fifteen years before that song came out, Pee Wee Crayton from New Orleans, recorded and released this obscure rhythm and blues song on the New Orleans’ Imperial label.

    http://www.youtube.com/watch?v=_Dfh9QIjR3Q

    There are clean re-mastered versions of that record and I have one; none on YouTube, unfortunately. Crayton did not play solid body guitars in his early career (prior to about 1958). If he got that sound from an amplified acoustic, that would be astounding. It’s astounding to get that sound from ANY guitar in 1955.

  8. Robert Bruce Thompson says:

    Yep, looks like Crayton ripped off the Beatles, 15 years before the Beatles wrote it.

    Speaking of sounding familiar, Jethro Tull’s Living in the Past came up on random play a few days ago. I kept thinking it reminded me of something and I finally realized it reminded me of Take Five. Not the melody, as it turns out, but they’re both in 5/4.

  9. jim' says:

    Bob,

    Yes the site has had its share of wonkies.

    But fercryinoutloud, it’s WordPress, and a competent admin should be on top of such things.

    If someone will remind me why I think _Look Homeward Angel_ is a better American novel than say, perhaps, _Great Gatsby_ or some monosyllabic work by Hemingway, I’d be most amused.

    Twain will get first consideration.

    jim`

  10. Miles_Teg says:

    Brad wrote:

    “What struck me as hilarious was the phrase “reach out”. Has valley-girl dialect become mainstream? Do you guys “reach out” to your customers, or do you just contact them?”

    A few weeks ago my boss said he’d allocate a “resource” to help me with an unfamiliar task. A “resource” is, as I’m sure you’ve all guessed, the current managerial term for a person.

    There’s nothing I enjoy more than taking the piss out of users of new jargon that isn’t necessary and doesn’t add any value to the conversation. That’s why I sometimes indulge in, as seriously as I can manage, using PC terms and obscurating jargon. Sometimes people realize I’m mocking them, sometimes not.

    George Orwell, may peace and blessings be upon him, would be spinning in his grave.

  11. Miles_Teg says:

    RBT wrote:

    “I can honestly say that I have never reached out for a customer. I have emailed them, snail-mailed them, telephoned them, and so on, but somehow I never got around to reaching out. Anyway, is that illegal in some states?”

    Depends on how old they are.

  12. Lynn McGuire says:

    I went to another bank today, explained the situation, and pointed out that as of April, I will no longer be a US citizen. The answer? It doesn’t matter. They are very sorry, but they do not dare take any new business from anyone even vaguely associated with the USA. Having been born there is sufficient. No one is saying what blackmail the US is using to inspire this level of fear, but it must be impressive (and almost certainly extralegal).

    BTW, what is the deal with all the one percenters leaving the USA? I see that Tina Turner has moved to Switzerland and renounced her citizenship also. Do you guys know something that we do not know about the future of the USA? Is Nehemiah Scudder getting ready to become the first USA dictator XXXXXXXXXX First Prophet?

    Looks like once a USA taxpayer, always a USA taxpayer. Good luck with that, you may need it.

  13. Chuck W says:

    @Brad Can you not do banking with another country’s bank? like Deutsche Bank or somebody in Britain or Luxembourg? Or are they bound to the same craziness in Switzerland that the domestic banks are?

    I know there were a number of Turkish banks with branches in Berlin while I was there, so surely there are foreign banks with branches in Switzerland?

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