Australia's Science Forum

STOP PRESS Bubbling away most of yesterday, (not me, the CO2!!) and had a good result. Lots of powdery stuff that looks like sodium bicarb if you use your imagination. For those giving this prac a try, I used 3M HCL, lots of. Kept replenishing the marble chips . The ammonia soln was 7% . I'll keep t...

Solvay process is a method of producing Sodium Carbonate . You begin by bubbling CO2 through an ammonia/NaCl solution. I do this by adding HCl to Calcium carbonate, and bubbling the gas through ammonia soln sat'd with salt. As the reaction proceeds, sodium bicarb precipitates (supposedly!) So you fi...

Hi all,
This is coming up, and I wondered if anyone had some clues to a successful prac. It's the first part, the formation of Sodium Bicarb that gives me grief. This year, I am going to try a lower concentration of ammonia (7% instead of 28%)
Any ideas would be appreciated.
Ellice.

Hi all,
We have 650 students 7-12. Six labs, which run pretty much full time. I work a 6.5 hour day.I also do a bit with our Junior School (K-6), and even the Preps! They're my favourite, as they actually applaud the demos! Nothing like an appreciative audience.
Good luck Sassi.

Hi all,
I am trying to find U tubes/drying tubes, that are 100mm in length. I find the carbon rods sit perfectly in them. I have some here that were purchased some time ago, but the shortest ones from suppliers are 150 mm. Any help would be appreciated.
Regards, Ellice.

Hi all,
I printed out my MSDS's on white paper for non hazardous, and red for hazardous. I didn't think there was any stipulation for appropriate colour.
Cheers, Ellice.

Hi all, Had a lok over the Cation and Anion Testing prac, and according to my notes, I have Ba++ forming a ppte with Sodium Sulfate, but Ca++ doesn't. And Ca++ forms ppte with Sodium Hydroxide, but Ba++ doesn't. I did fiddle with concentrations until I got the "right" result! For the IronI...

Hi all,
Just reading all the agar plate fiascos, and thought I'd pass on this tip. I only leave the plates in the incubator until a bit of stuff starts growing (2-3 days), then put them in the fridge, (I have one for Science stuff), and tell them whatever they want to hear! E.

Hi Rainbow sky, Just catching up on Chemwatch, so hope this reply isn't too late. We used Pot nitrate pH 7 5%w/w salt Amm chloride 5-6 Sodium sulfate 7 Magnesium sulfate 7 Sodium chloride 7 Magnesium chloride 7 Calcium acetate 9 Sodium carbonate 10 Sodium H sulfate 3 Sodium acetate 9 I just adjust w...

Hi all, We've been doing this experiment for a few years now, and using some funny looking things that I made ages ago. But when I read about the plastic air locks (which we've been using in Chem for Fermentation), I suggested to the Bio teacher we give these a go. I love it when they think I'm a ge...

Hi Ross,
In the past, we have had clear rings around the antibiotic areas, but the last few years have been a bit of a non event. Don't know whether it's the kid's technique or what. I'm going to try the suggestion of adding nutrient agar. Thanks for that tip.
Ellice.

Hi all, We are doing Disease with Yr 12 Bio at the moment, and doing lots of pracs with agar plates. One of our pracs involves E Coli and Staph Albus, and the antibiotic mastrings, which we have done every year with mixed success. I use the standard agar (peptone, salt, sugar, vegie, agar), and was ...

Hi Estelle,
Could you please add me to the list for Risk Assessments. Much appreciated.
Regards, Ellice.

ebrown@tigs.nsw.edu.au

Hi all, Had an incident yesterday while heating solder during a prac, where a girl had a slight asthma attack and needed to use her puffer because of fumes!!!! There was a bit of burning of sugar and salt going on at the same time, with the accompanying smoke, so who knows. Anyway, the parent is hou...

Hi All, It's really interesting reading how everyone does it. (preparing pracs I mean!) I have a large diary, with a page for each day, and teachers write in what's required. As we use the Heineman textbooks for 7-10, I know whats coming up, and usually I just get an Expt name with page number, room...

I always thought faecal was faecal, no matter where it was!!!

To people using Streamwatch,
Can the kit be used for testing sea water? I have some kids who want to test faecal levels at different beaches, and I had an idea the Streamwatch kit was only for freshwater. Any help would be appreciated.
Ellice.

Hi all, I've been looking back at comments on radioactive sources, and noticed someone mentioned that one of the sources had a short life. Could that be Alpha, as we haven't had much luck with it this year. Are people in the habit of replacing their sources? It's something that comes up once a year,...

Thanks for all the help gang. I was able to give the boss some info, and he was impressed. I didn't let on about the 'Chemtalk connection'. Do you mind if I take all the credit? I like the people here thinking they can't do without me!!

Thanks again, Ellice.

Hi everyone,
I have been asked to source and get prices for new lab stools. Any ideas?
Regards, Ellice.