Glass spotting/precipitation plates.

[fibreweb]

My chemistry teachers like the glass spotting/precipitation/dropper trays ( or whatever they are called) rather than the white ones as in them it is easier to see a white precipation.

These trays last time I bought one, several years ago were $ 27 odd each. We have broken 3 more over the last year and I have been asked to replace them but I can't remember where we purchased them from. I have searched through several catalogues with out sucess. It doesn't help that nearly each one calls them a different thing!

Does anyone else have these and could tell me where they came from?

Thanks,

Wendy

[sunray18]

We don't use those any more. We have purchased plastic ones from a supplier - they look like they are made from the same stuff as overhead transparencies. They are A4 size and have 4 rows of 17 indentations. They are sold in packets of 20 and cost about $20 for the pack - it may be a little more now.
As they are clear you can put black paper under them to see white precipitates.
I also use them when the Yr 10's do household chemicals. I have prepared a printed sheet that sits under the spot 'plate' so they can track the chemical and the indicator they are using. Lots less use of chemicals and indicators and reasonably easy to wash up.AND no breakages!
I am told you can make your own from overhead transparencies by heating the m with hot water and using a suitably indented base to make the mould - eg an egg carton.
I am a little lazy - - and I can't see the point of me wasting a couple of hours trying to make something which cost less to buy than my meagre wages for that item!

[lada]

We use those plastic spotting plates as well. I still have a large number of glass plates, but I cannot remember where we bought them from. The plastic sheets work well, you can put white paper under for dark precipitates, or black backround for coloured once.
There are so cheap, I would not waste my time by trying to make them.
lada

[bindi]

Can I suggest acetate sheets/ the old overhead transparency sheets, A4 size or cut them in half, much cheaper.
I also have some labelled in a grid/table format which tells students what to add. We also use black paper behind them like Lada suggested.
Some precepitates can be washed or wiped off with paper towel, when they get to marked just chuck em!
Easy

[lizzieb]

We use OHP transparencies too, marked with a large grid. Laid straight on the bench, kids move plain paper underneath so some show up better (our benches are grey). Easy to wash afterwards, throw 'em away when they've had it, and CHEAP!!

[noona]

We use the same a Liz but I laminated the white paper and they are easy to clean just wipe over with a damp cloth
We also have the plastic ones that come with 7 x 14 per row but the laminated sheets work better so the Teachers say
Noona

[Whspa]

We use laminated white paper as well. The paper is marked with a table with the cations and anions listed and a large _* in the centre of each cell.