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Phenylethylamine wrote:

ribonucleicacid621 wrote:Sometimes you can have problems doing iodine test with cornstarch. Make sure the concentration of cornstarch in the test tube is high enough, otherwise it may not change color. This happened to my partner during invitationals.

If you drip Lugol's solution (KI) onto cornstarch- straight onto the powder, in a well plate or something like that, not in solution- you should definitely see it change color.

PHENYL! Congrats to you and your team. =]
I don't know if you did powders or not, but do you remember what powders there were? I'm just really curious if I actually got them right or was just falsely confident.

personasaurus rex wrote:

Phenylethylamine wrote:

ribonucleicacid621 wrote:Sometimes you can have problems doing iodine test with cornstarch. Make sure the concentration of cornstarch in the test tube is high enough, otherwise it may not change color. This happened to my partner during invitationals.

If you drip Lugol's solution (KI) onto cornstarch- straight onto the powder, in a well plate or something like that, not in solution- you should definitely see it change color.

PHENYL! Congrats to you and your team. =]
I don't know if you did powders or not, but do you remember what powders there were? I'm just really curious if I actually got them right or was just falsely confident.

Thanks! I did powders, but not especially well (I've done Forensics at only one competition prior to States, and the fact that I used to do Science Crime Busters is pretty unhelpful since nearly all the powders/reagents are different). All I know for sure (at least, fairly sure) is that there was a glucose (Benedict's turned red), a potassium chloride (violet flame test) and probably at least one sodium chloride (crystalline + yellow flame test- less conclusive than the other two, though). I mostly guessed on the others.

oh haha well you did well anyways so doesn't even matter =P
I was just reaaaly curious because one of the questions was like "which given powder is used for Silly Putty" and its H3BO3 but i didn't get H3BO3 in the powders... I even checked them all over three times! It's been gnawing at me lol

personasaurus rex wrote:I was just reaaaly curious because one of the questions was like "which given powder is used for Silly Putty" and its H3BO3 but i didn't get H3BO3 in the powders... I even checked them all over three times! It's been gnawing at me lol

I wrote boric acid for one of them (the first one, if I recall correctly), although it was more or less a guess. Got the question wrong, though; I had a bunch of uses for the powders on my notes sheet, but Silly Putty wasn't one of them.

Just curious. Does anyone else's regionals give hardly enough time to do the event? We only identified 4/8 powders and no fibers or polymers. I went through and did as much as I could in the last 15 minutes to figure it out.

You had to have 50 min to do it because that's the time limit, it may have been that you were so concentrated on the event that the time just seemed like 20 instead of 50, that's what happened to me last year and I didn't finish the test.

It just seemed like there was way too much on my test to finish it all in the time period.

Sae wrote:It just seemed like there was way too much on my test to finish it all in the time period.

Some event writers will intentionally make the event a bit too long to finish, because that way it's easier to tell which teams really knew their stuff. If the event is easily finishable within the time, multiple teams might finish the whole thing and have very similar scores, so they make it more difficult and longer to separate out the scores of those top places.

Phenylethylamine wrote:

Sae wrote:It just seemed like there was way too much on my test to finish it all in the time period.

Some event writers will intentionally make the event a bit too long to finish, because that way it's easier to tell which teams really knew their stuff. If the event is easily finishable within the time, multiple teams might finish the whole thing and have very similar scores, so they make it more difficult and longer to separate out the scores of those top places.

Our proctor, is absolutely ridiculous haha. He's the same proctor that does my regionals, but I never actually took one of his tests until last weekend. I heard so many stories about him, how he tries to outdo himself every year and make the test harder. 40 minutes was all we got, and me and my partner barely finished =/

personasaurus rex wrote:

Phenylethylamine wrote:

Sae wrote:It just seemed like there was way too much on my test to finish it all in the time period.

Some event writers will intentionally make the event a bit too long to finish, because that way it's easier to tell which teams really knew their stuff. If the event is easily finishable within the time, multiple teams might finish the whole thing and have very similar scores, so they make it more difficult and longer to separate out the scores of those top places.

Our proctor, is absolutely ridiculous haha. He's the same proctor that does my regionals, but I never actually took one of his tests until last weekend. I heard so many stories about him, how he tries to outdo himself every year and make the test harder. 40 minutes was all we got, and me and my partner barely finished =/

I love the NY Forensics supervisor. He's also the national supervisor, and yes, his tests are hard, but they're well run and well thought out.