Montessori Elementary Homeschool Blog - with documentation of our infant Montessori, toddler Montessori, and primary Montessori experiences; as well as preparation for the upcoming adolescent Montessori homeschool years.

Friday, January 25, 2013

Geography Album and Potassium Chromate

Oh wow. Am I scared. We almost made a HUGE blunder.
(ok maybe not that huge, but it sure made me sick to my stomach)

We have these chemicals we use according to album pages in the geography album (forms of matter, chemical interactions) and the biology album (needs of the plant).

I have had supplies on hand to use with my son and have had the *correct* items. Tiny amounts purchased from a Montessori school that also used the same chemicals. We labeled each smaller container very carefully and everything was FULLY accurate. Still is. I'm just running low.

To do the presentations, I reviewed the album pages beforehand, used all proper safety procedures, and all has been *wonderful.* We don't use chemicals with similar names, so it is easy to keep them organized; and we only get out the chemicals we need when we need them.

The problem showed itself when I went to replace these chemicals the other night. I used the supply lists I created for my geography and biology albums, added stuff to my cart, but came up with two items that were not available at the top-notch science supply company I have come to love the absolute most because they are so homeschool-focused: Home Science Tools.

I e-mailed a Montessori comrade to ask where she got her supplies for potassium dichromate (geography album) and calcium nitrate (biology album).

Did you catch what I just wrote? 

Some background: 
In AMI training, the presentation is given to the trainees. The trainees furiously take notes by hand or on their laptops, while also trying to watch what is going on. Monday of each week of elementary training (primary was a bit different), all album pages from Monday through Friday of the past week are printed out, page-numbered, tucked into a large envelope and handed in. Album readers stop by the training center after-hours (so we can't know who they are and follow them home! ;) ), to drop off what they reviewed from last week and pick up the new week's set. The envelopes are THICK - anywhere from 80-200 pages each week.

A "lucky" few were then read by the trainers as well, before being returned sometime later in the week.

Changes are made based on the comments. Album pages can be required for re-submission or not, based on the trainer's thoughts; then final album-checks/reads are done at the end of the course.

But SO many typos slip through, grammatical errors... but the accuracy of the album page is supposed to be there.

I was one of those lucky ones that always had my album pages double-checked (probably to make sure I wasn't inserting Catholicism and homeschooling into a Catholic woman's work).

Yes, I just said that, and yes you probably read my voice tone accurately. I am extremely disappointed and disillusioned with AMI elementary training as it is - as far as the personalities and agendas of the people involved today (the content is fantastic!) - but through that many readers (and even my own use! but then, I had the material on hand and skimmed the page, there isn't another chemical with a similar name, and we're not supposed to be reading from the album pages as it is - they are supposed to be used for skimming/reviewing - I was using them properly! They were supposed to be error-free!).... and well, I just don't know what the chemical reaction would have been.

The fact is potassium dichromate is a vivid red-orange color; potassium chromate is yellow-gold. And I know that you are supposed to use just enough to make a brilliant gold color in the water - when a bit of lead nitrate is mixed in, a sediment precipitates down (you'll have to research that one to find out what is happening ;) ). So I would NOT have actually used the orange-red material, had I purchased it, opened it and saw a different color like that.

But the fact that it COULD have happened... scares me.

I am SO glad that Home Science Tools doesn't carry it.

Potassium chromate is a yellow chemical 
indicator used for identifying concentrations
of chloride ions in a salt solution with 
silver nitrate. It is a class two carcinogen 
and can cause cancer on inhalation. 
Potassium dichromate, K2Cr2O7, 
is a common inorganic chemical reagent, 
most commonly used as an oxidizing agent
in various laboratory and industrial applications. 
Molar mass294.185 g/mol
IUPAC IDPotassium dichromate(VI)
Boiling point932°F (500°C)
Density2.68 g/cm³

I spent the next 4 hours combing through my albums to make sure every other indication was absolutely correct. That is the only such potential safety error. Whew. A few more grammatical errors; a few missing commas or periods. Ok.

Home Science Tools does carry the potassium chromate, so in the cart it went. Geography - CHECK.

Now for Biology: 

But in doing further research on the calcium nitrate, I wonder if I should be adapting that presentation to use a more natural substance. This one is man-made and people going for organic don't typically use it from what I read.
****Does anyone have a suggestion for replacement? The Biology presentation here is to set up an experiment with plants growing in several different glass jars of water - one is just water; one is calcium nitrate in water; one is magnesium sulfate in water; one is potassium phosphate in water; one is ferric chloride in water; the last jar is all those items in the water for a fully healthy plant.
(NOTE: magnesium sulfate can be bought very cheap in the pharmacy section - it is simply "Epsom Salts")
Ideas for the calcium nitrate?

UPDATE: I am still looking for a replacement for the calcium nitrate - something natural, organic....

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