Search found 623 matches

by Robb
29 May 2009, 14:36
Forum: Forum Support Desk
Topic: Copper Sulphate Seed Crystals
Replies: 3
Views: 8676

Re: Copper Sulphate Seed Crystals

Hi All, The slower the rate of cooling the larger the crystals will grow, placing a seed crystal in with the solution will entice the crystal/s to begin growth. Fast cooling rapidly forms small crystals (Just use granite as an example... as the ignious rock cools quickly the smaller crystals form). ...
by Robb
22 May 2009, 23:54
Forum: Announcements
Topic: Off to Uni Again
Replies: 39
Views: 12029

Re: Off to Uni Again

Hi All, I thought I would put this post here as I think this is the most appropriate place. I am still continuing with studies at the moment so I do hope that you understand that there could be a little time between posts, I will however endeavour to respond ASAP but in sone instances this may not b...
by Robb
08 May 2009, 12:53
Forum: Sourcing Materials & Eq Repairs
Topic: Stannous Nitrate
Replies: 13
Views: 4328

Re: Stannous Nitrate

Hi all,

Hmmmmm.......

Cheers,

Robb.....
by Robb
01 May 2009, 09:48
Forum: Chemistry and Labware - General
Topic: Back to the grind stone
Replies: 39
Views: 9573

Re: Back to the grind stone

Hi All,

I am back from Uni now and I have added to the Astronomy post for this week night sky viewing. Had a great time, very busy though but I have returned with 9 assessment tasks due on the 25th may and 3 assignments due on 5 June. Apart from that its all smooth sailing.

Cheers,

Robb.....
by Robb
08 Apr 2009, 13:08
Forum: Announcements
Topic: Hi All
Replies: 3
Views: 1375

Re: Hi All

Hi All,

I Forgot to mention that I will available after 29th of this month.

Cheers,

Robb.....
by Robb
05 Apr 2009, 20:14
Forum: Announcements
Topic: Hi All
Replies: 3
Views: 1375

Hi All

Hi All, Just letting you know during my University studies I will be available to continue with Chemtalk during infrequent visits until the end of June. I understand that there will be times where I may need to be contacted and these would be best forwarded to my Corporate E-mail address: robert.cro...
by Robb
23 Mar 2009, 20:53
Forum: Chemistry and Labware - General
Topic: Bromothymol Blue
Replies: 5
Views: 1405

Re: Bromothymol Blue

Hi rae, Just bear with me as I try to eliminate the possibilities.........I'm trying to justify any changes if any...... If the colour of the original soloution is not the problem take a look at THYMOL BLUE the difference between Bromothymol Blue and THYMOL blue is a colour change from Blue is to Ye...
by Robb
23 Mar 2009, 11:51
Forum: Chemistry and Labware - General
Topic: Bromothymol Blue
Replies: 5
Views: 1405

Re: Bromothymol Blue

Hi All, Bromothymol blue is called the latter because the dye itself is blue, have you tried to neutralise it to a green solution first as this is the correct colour for this indicator. Try it and see what happens. Just set it to green with some NaOH (0.1M) until the green colour persists.. Alot of ...
by Robb
13 Mar 2009, 07:09
Forum: Chemistry and Labware - General
Topic: making up Universal indicator
Replies: 37
Views: 11764

Re: making up Universal indicator

Hi All,

If you find yourself with the same problem, simply add dilute HCl until you can drive the Universal Indicator back to the green colouration.

This will not affect the solution in anyway when it is needed.

Cheers,

Robb.....
by Robb
06 Mar 2009, 06:57
Forum: Chemistry and Labware - General
Topic: Tin II Chloride
Replies: 6
Views: 2525

Re: Tin II Chloride

Hi All, Just to make things a little easier, as acidifying solutions give the Metal Salts, (And, I don't know if you have noticed but it is metal salts only that you acidify), keeps the ionic separation rather than allowing the oxidation of these solutions of interest. This also accounts for keeping...
by Robb
28 Feb 2009, 21:58
Forum: Announcements
Topic: MSDS Sorry
Replies: 35
Views: 10792

Re: MSDS Sorry

C

Could I raise an important issue with this,

What happens when the computer network is down or there is/are power outages. Etc.


Cheers,

Robb.....
by Robb
28 Feb 2009, 21:21
Forum: Chemistry and Labware - General
Topic: distilled water
Replies: 52
Views: 22617

Re: Distilled Water

:D Im very glad this subject has come up cos Im just about to order 40 L of distilled water at a cost of ninety dollars because our distilled water (previously bought) has a pH of 5.5. The chem teacher doesnt want me to use it to make up senior chemicals, is it really a problem???? Also I bought pH...
by Robb
26 Feb 2009, 12:56
Forum: Chemistry and Labware - General
Topic: Rinse aid for glassware??
Replies: 8
Views: 2801

Re: Rinse aid for glassware??

Hi All, be careful as rinse aid is alkaline and will defeat the purpose of Titrimetric Analysis.

Just out of pure curiosity.

Cheers,

Robb.....
by Robb
26 Feb 2009, 12:32
Forum: Biology, Physics...
Topic: Viscous Liquids
Replies: 12
Views: 3685

Re: Viscous Liquids

Hi all,

Another solution for consideration is Tomato Sauce nice and viscous.

Cheers,

Robb.....
by Robb
26 Feb 2009, 12:28
Forum: Chemistry and Labware - General
Topic: standardized NaOH
Replies: 20
Views: 12847

Re: Standardised NaOH

Hi All, For standarisation of NaOH we need to make sure you have the primary standard KHP or Potassium Hydrogen Phthalate. This is then measured against the prepared NaOH. If you need the calcs let me know, this could benefit most people. I don't have a problem with sharing this information... Good ...
by Robb
23 Feb 2009, 23:50
Forum: Chemistry and Labware - General
Topic: Silica Gel
Replies: 2
Views: 1290

Re: Silica Gel

Hi Maria, It is fine to wash the Silica Gel, Although it will probably smell, it will smell anyway when you place it in the oven.. Natural phenomena for Silica. Make sure when you clean it that you have the appropriate PPE donned and Redehydrate and move on.. This won't be an issue for you at all. C...
by Robb
21 Feb 2009, 18:48
Forum: Chemistry and Labware - General
Topic: sodium metal
Replies: 31
Views: 11898

Re: sodium metal

Hi All, We need to consider the schools outside NSW when we suggest that certain chemicals are banned as this can be missleading, to others and missleading information can be used and ordered in a Court of Law. Just be careful with that one...... Sodium metal when purchased from reputable Chemical s...
by Robb
09 Feb 2009, 12:21
Forum: Announcements
Topic: Change in School Times
Replies: 2
Views: 1390

Change in School Times

Hi All, Our school here at lake Munmorah H.S. has changed it times for the day structure. We now begin rollcall at 8:00am and finish the last period at 2:00pm. This will not affect my performance here on Chemtalk, but if there are any requests that need replies then I can certainly get back to you s...
by Robb
26 Jan 2009, 00:49
Forum: Chemistry and Labware - General
Topic: Chemistry RA's
Replies: 13
Views: 4398

Re: Chemistry RA's

Hi All, Have all RA's on computer and therefore any adjustments can be saved as a new file and you can continue from there. Online RA's are few and far between. I don't really trust them because I have not tried expts that they are binded to and RA's will differ from person to another as there could...
by Robb
26 Jan 2009, 00:44
Forum: Chemistry and Labware - General
Topic: And just like that, it is all over...
Replies: 35
Views: 11052

Re: And just like that, it is all over...

Hi All,

First day back for us here in NSW is Tuesday 27th Jan.

I have been away from home now for two weeks and I am looking at updating the Astronomy Thread. Be Warned! There have been some interesting things happening so watch carefully...

Cheers,

Robb.....