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Re: Can't Judge a Powder B
Posted: March 31st, 2010, 1:23 pm
by sciolympian
i'm going to change the quadruple post. okay????
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 1:24 pm
by sciolympian
EASTstroudsburg13 wrote:You could just edit your previous posts or something like that. And only one of them is a question, so it didn't sound like you wanted an answer for the three ones that came previously. So I agree with zyzzyva in that you could have posted that in at most 2 posts, preferably one.
chill.... i changed them now.... happy?
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 1:30 pm
by sciolympian
acanoli wrote:sciolyandmathcounts, how do you do hygrocscopy with a balance? Usually we just put a little of the powder on a spot plate and add a drop of water, and see if its absorbed/adsorbed by the powder. Are we doing it wrong?
Also when you say "the 4 reagents," do you mean all of those are required? Because i think my rules might have been outdated. Ours say only H2O and HCl are required, but they can give you anything else if they want, if i'm remembering correctly. Was it just a coincidence that you got all 4 of those at both competitions?
they also give you NaoH.... well in delaware they do.
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 2:44 pm
by zyzzyva980
sciolympian wrote:how do i delete this post?
You can only delete posts in the General Chat forum, and only if it hasn't been replied to. For in the future, try to fit all the information in one post. Now, back to Can't Judge a Powder stuff.
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 2:48 pm
by gneissisnice
sciolympian wrote:acanoli wrote:sciolyandmathcounts, how do you do hygrocscopy with a balance? Usually we just put a little of the powder on a spot plate and add a drop of water, and see if its absorbed/adsorbed by the powder. Are we doing it wrong?
Also when you say "the 4 reagents," do you mean all of those are required? Because i think my rules might have been outdated. Ours say only H2O and HCl are required, but they can give you anything else if they want, if i'm remembering correctly. Was it just a coincidence that you got all 4 of those at both competitions?
they also give you NaoH.... well in delaware they do.
HCl, NaOH, and H2O are the three reagents you will always see. Additional reagents can include Iodine (Lugol's solution), phenolphthalein, bromothymol blue, silver nitrate, and Benedict's solution (only if they give you a hot water bath). I don't recall seeing any others, but be prepared for them.
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 3:18 pm
by Draylon Fogg
Any tips on things that should be focused on??
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 4:15 pm
by dholdgreve
Red Cabbage juice is another natural reagent that seems like it ALWAYS stumps at least half of the teams!
Re: Can't Judge a Powder B
Posted: March 31st, 2010, 5:42 pm
by 4science
With the red cabbage juice--do you just add drops of it to the aqueous solution and see if there are changes?
Re: Can't Judge a Powder B
Posted: April 1st, 2010, 8:10 am
by Draylon Fogg
Ok, so how would you go about testing with the Red Cabbage?
Re: Can't Judge a Powder B
Posted: April 2nd, 2010, 9:12 am
by sciolyandmathcounts
I assume it would be the same:
pH
Temperature
Conductivity
etc.