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Re: Can't Judge A Powder B

Posted: February 19th, 2014, 11:39 am
by hippolover
Yes, computergeek3, please PM me--thanks !

Re: Can't Judge A Powder B

Posted: February 24th, 2014, 12:47 pm
by sandhya_326
I have simple digital conductivity meter; Hydrophonic aquarium EC conductivity tester meter (us/cm) bought from Amazon. It gives some number when you put it in distilled water or aqueous solution of any powder. Is it good for this event or I need to get a conductivity meter with LED light etc. Which one is best? Any suggestion is appreciated. My kids went for invitational and they did not have any question on conductivity, so wonder whether I need to buy with LED or just work with what I have. Please suggest me. Thanks

Re: Can't Judge A Powder B

Posted: February 24th, 2014, 1:15 pm
by sandhya_326
I have a question about observation. Do kids need to write how much powder they took for test? For Example. Do they need to write 1 gm of powder is taken in 5 ml of water? Also, if event supervisor does not provide scale then how do they measure the powder and write about it? I am assuming that to get five points they need to write everything like how much powder and how many ml etc. Can someone clarify this point?

Re: Can't Judge A Powder B

Posted: February 24th, 2014, 8:00 pm
by mitchell40
aljones wrote:What is the cleavage of a powder and how do your test for it, what would you write for observations? Thanks
Cleavage is nothing you need to know for this event. It is used to describe rocks and minerals.

Hope this solves some of your worries!

Re: Can't Judge A Powder B

Posted: February 25th, 2014, 11:51 am
by dholdgreve
sandhya_326 wrote:I have a question about observation. Do kids need to write how much powder they took for test? For Example. Do they need to write 1 gm of powder is taken in 5 ml of water? Also, if event supervisor does not provide scale then how do they measure the powder and write about it? I am assuming that to get five points they need to write everything like how much powder and how many ml etc. Can someone clarify this point?
Yes, this event deals with both the qualitative as well as the quantitative aspects... and BTW, don't ever substitute the word "substance" for the word "Sample," as there are certain E/Cs that will not give any credit for substance, but full credit for sample... I don't understand it, but that's the way it is... Then again, you may be better off sticking with the word "powder" since it is in the title, but you will probably find an E/C that will take off for that as well if they provide you with a crystal.

Re: Can't Judge A Powder B

Posted: March 12th, 2014, 6:49 pm
by pandy3843
I'm just wondering, but do any of you know what hygroscopic means because it appeared at the invitationals and regionals but I never figured it out. Thanks!

Re: Can't Judge A Powder B

Posted: March 12th, 2014, 7:41 pm
by Schrodingerscat
pandy3843 wrote:I'm just wondering, but do any of you know what hygroscopic means because it appeared at the invitationals and regionals but I never figured it out. Thanks!
Basically it means that the powder will absorb moisture from its surroundings. Hygroscopic powders tend to clump as a result.

Re: Can't Judge A Powder B

Posted: March 12th, 2014, 9:17 pm
by pandy3843
Schrodingerscat wrote:
pandy3843 wrote:I'm just wondering, but do any of you know what hygroscopic means because it appeared at the invitationals and regionals but I never figured it out. Thanks!
Basically it means that the powder will absorb moisture from its surroundings. Hygroscopic powders tend to clump as a result.
Thank you soooo much! Can you give me an example of a hygroscopic powder?

Re: Can't Judge A Powder B

Posted: March 13th, 2014, 3:39 pm
by Alisa
hi, i was wondering how to find volume for this event. thanks

Re: Can't Judge A Powder B

Posted: March 13th, 2014, 5:10 pm
by pandy3843
Alisa wrote:hi, i was wondering how to find volume for this event. thanks
To find the volume, you would take the powder sample they give you and put it in a container that has ml measurements. Then you can see the volume after you make it level. I hope this helps and can someone else give some extra insight because I am still rather new to this.