elb's hovel of thoughts

Monday, May 22, 2006

And the research continues.. to a bad start

Day one of my lab research proper has finally started. My supervisor gave me a simple enough task: prepare a solution as the starting point for further molecular biology probing.

The protocol (aka experimental technique) was just several lines long. One part of it read 'add 1ml of 1M NaOH'. We had no fresh NaOH solution in the lab however; the last batch (ancient, I was told) was firmly sealed in its own volumetric flask.

No problem. Just make some. I did some simple arithmetic: one mole of NaOH requires 23 + 16 + 1 = 40g per litre. I thought of making a small 100ml batch since I only needed 1ml. So I measured out 4 grams of the stuff, chucked it into the beaker of appropriate water, and I got the magnetic stirrer and heating plate going.

Sure enough, the NaOH tablets soon dissolved. But I noticed a problem: they were not actually dissolved fully but were in a separate phase, forming an emulsion in the water. I frowned and pointed it out to one of the PhDs, who commented that it 'was just air bubbles'. At any rate, I took the beaker off the plate, and sure enough whenever the opportunity presented itself, the NaOH formed into solids again. Bah.

So I repeated it again with a volumetric flask and plugged in the stopper to prevent water from evaporating. After the NaOH had dissolved again, I moved the flask to a cooler area. I tried to open it after twenty minutes, thinking that the stuff would have cooled down sufficiently. Oh dear; a whole lot of it just flew out of the flask with a loud hiss, hitting the ceiling, the equipment all around it, getting onto my lab coat, onto my gloves, and onto my exposed face. Thank God for glasses though. Happily for me it was a relatively dilute solution (at least a couple times more concentrated and I'd have scars), but it was still ferociously hot. Of course, I spent several minutes washing my face, as per safety protocol.

The worst was yet to come though. I still had to make the bloody solution and was not in the mood to give up. So I took another volumetric flask, measured the NaOH, put it in, got it stirring etc. So I was watching the mixing from about a metre away, when the whole thing literally exploded as I tried to jump out of the way. Fortunately for me, it was more of an implosion than an explosion.

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The volumetric flask, with the bottom cut off cleanly.

Bah. Over 3 hours had passed; a fourth batch failed, and getting incredibly frustrated and annoyed after 3.5 hours of no results (not to mention that I hadn't eaten for over 8 hours), I trudged over to the next lab, asked another of the PhDs for a small sample, and got it.

Morale of the story: Ask.

8 Comments:

  • You need an explosion (implosion) to get a bottomless volumetric flask but I got a bottomless 250 ml beaker by just heating the beaker filled with water on a hot plate, while stirring.

    haha...

    I got the power...

    By Anonymous Steph, at Thursday, May 25, 2006 3:44:00 pm  

  • steph: well... it could be the same thing, since my flask was stirring quite vigorously before the bottom somehow sliced cleanly off O_o.

    Luckily for you that yours was only water!

    By Blogger elb, at Thursday, May 25, 2006 11:37:00 pm  

  • Scary stuff! I actually love Chemistry - hate Physics hence I think I love cooking which is similar to mixing up stuff.

    By Blogger boo_licious, at Friday, May 26, 2006 8:24:00 pm  

  • hi...actually i've been reading ur blog for quite a while...hehe...anyway what happened is just so cool!(ok minus all the mess) never experienced it before and plus getting the bottom sliced cleanly??? wow...incredible!

    By Anonymous liann, at Sunday, May 28, 2006 3:50:00 pm  

  • boo: Molecular gastronomy comes to mind :)

    liann: Hello hello! :) Fortunately for me and everyone else, it wasn't too concentrated to be corrosive. Don't try this at home (or should I say, the lab)!

    By Blogger elb, at Sunday, May 28, 2006 10:43:00 pm  

  • wtf...

    NaOH dissociates violently in water...

    And you had the gutts to put a tablet in the water :D, or was it the other way round?

    Kudos to you, in the name of science.

    By Blogger KEF, at Sunday, May 28, 2006 11:31:00 pm  

  • kef: Yes I know. I added the NaOH 'tablets' into the volumetric flask with a funnel and squirted a bit of DI water whenever it got stuck.

    When it was all inside, I added a bit of water and waited. Nothing. Shook it a bit. Nothing. So I added more water and shook it a bit. Nothing.

    So I added in a magnetic stirrer and got it going at a healthy pace while heating it gently. As I mentioned in my post, all it did was to melt into an immiscible second phase which emulsified when stirred and cooled back into the solid phase at any opportunity. It did not dissociate with the water to form my NaOH solution -_-

    By Blogger elb, at Sunday, May 28, 2006 11:57:00 pm  

  • Hmm...

    You make me want to go check NaOH t vs solubility right now but I'm just like you, too tired and busy working.

    So, this has to wait, cutie!

    By Blogger KEF, at Monday, May 29, 2006 12:48:00 am  

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