Can't Judge a Powder B

[sciolympian]

i'm going to change the quadruple post. okay????

[sciolympian]

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?

[sciolympian]

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 Because i think my rules might have been outdated.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.

[zyzzyva980]

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.

[gneissisnice]

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 Because i think my rules might have been outdated.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.

[Draylon Fogg]

Any tips on things that should be focused on??

[dholdgreve]

Red Cabbage juice is another natural reagent that seems like it ALWAYS stumps at least half of the teams!

[4science]

With the red cabbage juice--do you just add drops of it to the aqueous solution and see if there are changes?

[Draylon Fogg]

Ok, so how would you go about testing with the Red Cabbage?

[sciolyandmathcounts]

I assume it would be the same:
pH
Temperature
Conductivity
etc.