Magnesium powder for yr 12 Chemistry: Riskasses

[amandag]

Hello,
Magnesium powder is required for a Yr 12 Chemistry experiment, when putting this on Riskassess, it would not allow me to proceed. What is it rated in the NSW CSIS book ? Please. It is for the
Enthalpy changes in chemical reactions, Heinmann book 2.

[lurra]

In CSIC it is teachers use only so a red dot

[dime]

Hi
In the CSIS book it is rated for Teacher Only use. I don't have any of the chemical as we don't use it. Cheers

[RosalieM]

I have never had it requested. I would be checking if the ribbon can be used instead.

[nickyw]

If we need to use magnesium powder I just cut up the ribbon really really small. No complaints so far in fact it was the chem teachers idea.

[Judy R]

I would recommend the magnesium ribbon as metal powders are very risky ie can explode

[bigmack]

Just discovered this . Needless to say I'm a bit nervous dealing with it . obviously it has slowly absorbed moisture as our Chem store is cold and damp and has expanded and cracked the jar . There is now a split about 1-2mm wide that is exposing more air and moisture .
I'm going to keep a small amount as we use maybe a gram a year and dispose of the rest .
according to risk assess I can react up to 100gm with a dilute HCl and dispose of down drain with lots of water . Should be gone in three days . Quicker than getting a disposal mob out .

Magnesium Powder.jpg

Cracked Jar.jpg

See the Date on the container 1980 .42 years old
Just a suggestion that anyone that still has this , could experience a similar problem .

[Labbie]

WOW Bigmack, the things you so find.

[bigmack]

WOW Bigmack, the things you so find.

Yup ....this is what happens when you inherit someone's job that liked to keep everything

So the I discovered the practicalities of disposing of 100gms of this powder . Firstly , its this much .

100gm Magnesium Powder.jpg

I started with about 300mls of 2M HCl and added about a teaspoon to see what would happen .
It fizzes and foams up about a few cm and the beaker does get warm . So I setup a few beakers and just kept adding powder bit by bit to each .

spatular full.jpg

Hubble bubble.jpg

The reaction takes longer and longer and eventually the beakers start to go grey looking as the powder runs out of acid .

need more acid.jpg

At this point I just added a splash of some older jars of 5,6,8M HCl we had in the storeroom until eventually I had reacted all the Powder .
So now I have about 5 litres of Magnesium Chloride to pour down the drain with lots and lots of water .

ready for disposal.jpg

Definitely a lot more bother than I thought , but a lot cheaper and quicker than getting it removed .
And much to my relief , it did not spontaneously combust

[Labbie]

Well done you, it's the right thing to do.

[melsid]

Well done bigmack.

When I started here I had a similar problem - lots of waste in the storeroom and nothing in the budget to pay for disposal. So I did my research and bit by bit disposed of what I could. By the time I was done, I could afford to pay a contractor to dispose of what was left.

My biggest problem was a full Winchester of sulfuric acid that had turned black!

[mtg]

It becomes less explosive as it ages and absorbs moisture. I bet if I got rid of it a teacher would ask for it next week.