Australia's Science Forum

What strength NaOH would you recommend? I have several evaporating basins with charred remains from a jelly crystal prac which no amount of scrubbing is moving.

White cosmetic clay is Kaolin which you should be able to source from your nearest pottery or ceramics supplier in the quantities that you are talking about. Lyn.

I usually air dry the cobalt chloride paper to a certain point and then place in a jar with a screw top lid and about a half inch or more of silica gel in bottom of container. The silica gel must be a blue colour as I have found once it becomes pink it is no longer effective for removing moisture. I...

Hi Rhonda, Yes your numbering system would have been done quite some time back, probably from some obscure and now defunct textbook. Either keep the numbers as they already are or renumber for your own convenience. If you have a copy of a rocks and minerals identification book perhaps use the number...

Sue, I have never used more than a 2M H2SO4 solution for the voltameter. The use of 1M H2SO4 is also suitable. The amount of reaction depends on the setting of the power pack. I have never had a problem getting results. Personally I would never use Conc H2SO4 with this equipment. I think that is way...

Hi Lindy,

6M Naoh is 240grams per litre of distilled water. There is a lot of heat generated so try and keep your mixing container in cold water in the sink perhaps.

Lyn.

Apart from checking ceramic supply places for black iron oxide, try Mitre 10 or Bunnings. Just ask where the oxides are. (Might be handy to mention cement as well.) I have bought black iron oxide and made a solution with powdered cement to paint over the concrete between the rocks in my garden. I do...

Rosalie, Have looked up info on using Canada Balsam. "Balsam is applied to slide using glass rod. If it is too thick it can be diluted with a little xylene. Slides can be handled once balsam has hardened. Speed hardening by placing ....slide on warm hotplate, in a low oven or other warm place.&...

Hi Lindy, Doesn't your school have a maintenance man? There must be maintenance request sheets available in the admin office which you can fill out and your school should have a budget for maintenance issues. Or put in a written request to get brackets for your shelving and to have your tool board f...

I get virtually all my glassware from Omega Scientific in South Australia. The supplier is only a phone call away if there are any problems. He has replaced broken glassware (without me having to send back the broken bits) and if feedback from lab techs indicates that there is a problem with the qua...

I wear a lab apron on a daily basis and have one for each prep room. I don't wear them to the staff rooms - I'd melt before I reached the sanctuary of the airconditioning. Besides, after cleaning up after dissections I look like I've come from the abbatoirs. Not a good look at morning tea or lunch. ...

Hi Carol, If all else fails contact Workcover NSW for advice and perhaps check with your local fire department. Some years ago I had to remove a filing cabinet, which held teacher reference materials, as it was considered a fire hazard because of its close proximity to a chemical storage cabinet in ...

Hi Di,
I revitalise the blue litmus by holding the booklets over an open bottle of conc. ammonia in the fume cupboard. Just fan them a little to let the fumes have an effect. Blue litmus turns from pink to blue again.
Lyn.

Hi Lisa,
I would really appreciate it if you could email me the pdf for "Getting it to Work". Instructions on how to use some of our Physics equipment have disappeared. (Or maybe fell apart with age.)
My email address is lynda.ayr@ntschools.net.au
Thanks, Lyn.

Did this prac only once using beakers to crystallise copper sulfate/alum solution. Told teachers afterwards that they would be using disposable plastic petri dishes to recrystallise the solutions. Students let their solutions cool a little before pouring liquid into the petri dishes. The results are...

Hi Sue, Once upon a time I used to try and recycle dead rubber stoppers. Packaging tape wraparound, shaving thin slices off using single edge blades, etc. The realisation eventually set in that I was flogging a very dead horse and that the commonsense thing to do was to bin them. Show no mercy. Lyn....

Here in Darwin I source dry ice from BOC at Winnellie. Type in "BOC locations" and google Australia and you will find info on the closest BOC depot to yourself. Give them a ring, it is worth a try. If you pick the dry ice up yourself, don't forget to take the esky.

Lyn.

Just dirty the shiny zinc metal with a solution of copper sulfate first. The solution doesn't have to be strong. Have just tested a 0.2M CuSO4 solution and got blackening of the metal. Rinse the metal to get rid of the copper sulfate, dry and then add the acid. Dirty zinc reacts much quicker than sh...

Hi Robyn,

What's the prac you are using this stuff for?

Lyn.

Thanks ladies, Will have to initiate some action on getting access to the Chemwatch site. Until then it's a matter of trawling the internet trying to find appropriate MSDS sheets for my chemicals. Right now they all need replacing. Pommy: The website you mentioned keeps coming up as "network - ...