Australia's Science Forum

OK So this is a thread from a very long time ago, so I doubt the original contributors are still labbies, but I found it when looking for other information. I just read about this conservation of mass experiment the other day so thought I'd add my 2 cents worth in case anyone else comes across this ...

Merilyn1 wrote: ↑07 May 2021, 12:09 So, the stage was set - all teachers were on class. I snuck in with my bottle, zapped it a few times for one minute on 50% and voila! I have liquid agar. I did have to air out the staffroom before they got back

Great!!! I'm glad it worked out for you! haha they'll never know!

It's for conservation of mass though, not just precipitation. They must be weighing it before and after. Love the table on OHP sheets though!

OK so after clarifying with the teacher he will need 100ml for the 2 classes! Not each group. All good!

I've been asked for "at least 100ml per group" of lead nitrate and potassium iodide. I will make up 0.001M lead nitrate but that is a lot, right? I will talk to the teacher to see if they can reduce it to 10ml per group (or ask if it was a typo?) and get the same outcome (conservation of m...

Can you use a stirring rod to smoosh it up a bit? Do you have a magnetic stirrer hotplate? Maybe put it in a large beaker/small saucepan (if you have one) in a waterbath on that? Then once it's melted enough to transfer to a conical flask, pop the magnetic bean in and stir straight on the hotplate. ...

Hi Emma, It doesn't really last long. I do remember when I needed to keep some for later that if you keep putting phenolphthalein on top it helps to keep the colour and stops it drying out but I don't remember how long you can continue this. I don't remember keeping it for more than a few days to a ...

Thanks Merilyn! Would you consider the disinfectants and hand sanitisers to also be consumer products? I would think that they shouldn't need to have SDS unless there is a large quantity stored on site. This will sound odd, but this was advice direct from Safework NSW a couple of years ago: If the ...

Thanks Merilyn! Would you consider the disinfectants and hand sanitisers to also be consumer products? I would think that they shouldn't need to have SDS unless there is a large quantity stored on site.

Copied from: https://www.safeworkaustralia.gov.au/doc/hazardous-chemicals-register-fact-sheet "Consumer products are those that are packed primarily for use by a household consumer and are used in a manner consistent with normal household use. For example, laundry detergent packed in a 1 kg con...

Copied From https://www.safeworkaustralia.gov.au/sds#chemicals-that-need-safety-data "Keeping copies of safety data sheets Businesses must keep copies of SDS for chemicals they use and they must be readily accessible for all workers involved in using, handling or storing the chemical at the wor...

I do the chemical registers for the whole school. We have a company trying to persuade us to purchase their software for this (not going to happen) however they are saying there is a $3000 fine for any SDS missing and that things like toner cartridges need to be included. I have never thought about...

Thanks everyone, Yeah wants to relate to solar system, but I've said no, she just wants to do a prac I think. So as a demo only, these kids are still having trouble lighting bunsens. They are never going to understand what, why or how to do the prac., but anyway. Teacher didn't want it referred to ...

Yeah, I'd be pointing out to the year 7 teacher that if they do it now, they won't want to do it in yr 9. Maybe a demonstration of two compounds to show there's a difference would be ok, but not the full "flame test" prac. Is she an approachable teacher? Can you find out what point she is ...

That's a very good article, agregory. Thank you for sharing. Yes, I agree that science support staff should not be in the same classification as admin staff. There is a very different set of skills and knowledge required, as well as the increased responsibility of the health and safety of ourselves ...

Thanks bigmack, I think it's different as the cyanopaper one you just rinse with water (but same idea).

I don't recall having to clean cuvettes in the past, but my go-to (thanks to this forum) is napisan for glassware that won't come clean. Dissolve the napisan in warm water, then leave the glassware in it overnight (or weekend, as would be the case today). Hopefully a rinse in warm water and it will ...

PS - I would love to have the time to do multiple experiments. If I had the time, I would compare a meat sample and a fruit sample. I still stand by my suspicion that the tenderiser has just carried over in some recipes from when they used to do cheek cells.

I have written up a quick summary with photos in a word document. It's pretty rough and I would never submit it for an assessment!! :cheesy: It's too big to attach as a file and I don't have the ability to convert to PDF on this computer. If anyone wants the 'full' version I can try to PM or email i...

Oh sorry Merilyn, I didn't read your comment properly! The second class is doing the prac today so I will have a play when all the equipment comes back. I should go and make the extraction buffer solution up now without the meat tenderiser so I can do the comparison!