Australia's Science Forum

We use the soluble starch, so I know that one works. I am not sure about the potato one, but I would imagine, that it too, should work.
Lada

We have made up our own:
1cup of plaster of Pares
1cup of copper carbonate
1cup of sand
Mix with water and let it set overnight.
Break into pieces and crush in mortar and pestle
Lada

Be careful using unknow chemicals. Our kids are testing local water ways and the nitrate(or nitrite) test was scrapped because it was not safe for students. They are still doing the phos test.

The concentration in salt water might be lower, but the test will still show up if the faecal coliform is present.

Dear Ellice,
Our group is testing Dee Why creek near a lagoon and the salinity at hight tide is very high. I think the coliform can be tested by streamwatch kit. It will, at least, give them a good indication.
Happy testing
lada

It is a problem. You know, our theachers have to count the number of boxes going out and number of boxes collected back. We too, have those lighters, but teachers complain, that KIDS cannot use them, I wonder, who cannot use them.
lada

Hi Ross, that is cool. Our chem teacher did it and beaker froze to the mat.
Also the safe one is very distinctive, about 5-6oC drop in temp.
Just for that, karma is coming your way

Our teachers are sticklers for safety and sodium thiosulfate with HCL gives off supfur smell, so they will only do it in fumecupboard, so I only give it to senior students now. But you are right, it is an excelent example.

We just did some with yr9. Dilute HCl and Mg ribbon and dissolution of following substances in water: anhydrous CaCl2 KCl, NaCl,NaOH and KNO3 Let them do it in styroform cups with lids on them and insert thermometer throught the lid. make sure they take initial temp then completely dissolve the subs...

Good one,Ian :cheesy: just for that I give you extra karma. But I have a similar story. My young nephew had tropical fish, some expensive. He had a barra, tiny little thing, some tropical colourful fish and one day he caught a yabbie. next day there was few fish less and the rest as they say is hist...

Hi Lorrae, if all else fail, let me know and I can fax you the instructions(8pages)
lada

Yeh, same with our guy. He is pricey, but I am not sure what going rate is.
Good luck, Lada
Just for your troubles, I will give you extra karma

I just tried and have no problem.
Must use capital letters where indicated. i thought you can use lower case and it did not work.

Hi Lisa,
we got our fume cupboard from LABTEC and now they are coming here to service it.
Their ph number is 02 9488 8924.
Give them a call see what they say about Central Coast
Good luck Lada

MicroS/cm is a measurement of conductivity. To convert this to TDS in ppm, multiply microS by 0.64 to get ppm of total dissolved solids.
eg 25microS/cm is 16ppm(or mg/L) of TDS
Is thaT what you are after??
Lada

We have a Permutit deioniser and it does not waste any water. One hose in and out comes the clean water in the same amount. It works on ion exchange resin and about every 2-3 years needs its cartridge changed.
Water is still slightly acidic, but it was never an issue.
Lada

Ofcourse they speak English, media said so.
And they also catch a bus. There was a picture of some rock formation on mars and looked like a person waiting at a bus stop. Camera does not lie.
Ha Ha

Same here and iodine is tested only in fumecupboard. Good to see, the teachers are on the same topic.
lada

Hi, we have had ours for 8 years .We selected Data harvest, as this was the best option then. Must agree with Sassi, the teacher that uses them all the time has no problems but a few of the others always want me to help out. It is easy to use with or without computer. One technical support at Serrat...

Just for that I gave you extra Karma. Can you feel it???