Can't Judge a Powder B

[bubblebrian]

lol solon didn't do that well in can't judge a powder in state this year- 6th place

[melody2k6]

Are there any tests to tell if a powder is hygroscopic?

[melody2k6]

lol solon didn't do that well in can't judge a powder in state this year- 6th place

Why do you care about how Solon did at State? FYI, Solon might get gold at Nationals, because, as you can see, they're studying!!!!!!!!!! Even though your school got first for Can't Judge A Powder, it doesn't mean that you guys will do as well for Nationals.

[haven chuck]

Are there any tests to tell if a powder is hygroscopic?

A) Look in the 2007 test packet (2006 tests). There is an excellent description of the experiment that they were looking for testing for hygroscopic-ness on the CJAP test answer key.

[melody2k6]

We don't have the test packet.

[haven chuck]

We don't have the test packet.

This wasn't on the test this year, but here is what they wanted in '06-
Put a set amount of the powder in a beaker and weigh it. Leave it alone for at least 15 minutes and then weigh it again. If there is a change is weight, then it is likely hygroscopic; if not, then it isn't. However, this process can take a fair amount of time if you have a shared triple beam balance (when you have so little time to start with), so it is probably worth considering just writing down something to the effect of "The powder clumps". This simple would receive AT LEAST 3-4 points anywhere, though most Invitational/Regional/State supervisors would probably give it 5, and would take far less time.

[ichaelm]

Hmm. We just did clumping as an observation, and then we would test to see if it was hydrophobic by seeing if water made it wet when a drop was put on it. We would write "the powder does/does not adsorb to water." Note that "adsorb" is not a typo!

[2win]

Please tell me I don't have to police you on the boards, Brian.

I think there's a rule against using real names on Scioly. Give Brian a break! Meanwhile, you should realize that it's very coincidental that Solon asked a question about hygroscopic-ness...

Um, not to be mean or anything, but please refrain from posting non-related comments on study/building threads. You could always use PM's.

[melody2k6]

Please tell me I don't have to police you on the boards, Brian.

I think there's a rule against using real names on Scioly. Give Brian a break! Meanwhile, you should realize that it's very coincidental that Solon asked a question about hygroscopic-ness...

Um, not to be mean or anything, but please refrain from posting non-related comments on study/building threads. You could always use PM's.

Sorry. I have terrible judgement of simple things like that. Did anyone understand the question about the rotten egg odor? My partner and I had no idea what it meant.

[robotman]

Sorry. Did anyone understand the question about the rotten egg odor? My partner and I had no idea what it meant.

I think My partner and I did.
It was the Feric something (brownish color) that had the rotten egg odor