Page 8 of 9

Re: Forensics?

Posted: March 27th, 2009, 3:11 pm
by cyanoacrylateismybff
dholdgreve wrote:pH paper can be purchased as "Broad Spectrum" (i.e. 1-14), but can also be purchased as narrow range (i.e. 5-7 or 8-10, etc). In this event, with a half of pH point being critical, I'd make sure that you have narrow range acidic, narrow range alkali, and broad range to see which narrow range to use... The more narrow range will give you much greater color variation and should really help zoom in on the exact pH of the solution

The rules do not indicate quantity of student supplied material, so having three boxes of it should not be an issue, although it may be questioned. :ugeek:
Thanks, I hadn't really thought about that before. My team is good except for plastics pH paper and writeups. We still need to order it... Eek! I should probably do that...

My team is a bunch of procrastinators, including me. I just now finished the logo for our shirts and we're getting them made soon... Also, my bro and his partner built their ballista for trajectory 2 nights before the comp and still got 4th. LOL :lol:

Re: Forensics?

Posted: March 29th, 2009, 4:44 pm
by wattsworder
Hey does anyone know if it is possible to find a past forensics nationals or state test online? I've looked everywhere but can't find one.

Re: Forensics?

Posted: April 3rd, 2009, 1:06 pm
by wexs883198215
Oops just realized that someone had asked this question earlier :oops:

Re: Forensics?

Posted: April 3rd, 2009, 7:53 pm
by wexs883198215
Hey, watts,

You can go to http://www.scioly.org/wiki/2009_Test_Exchange for some tests. You can buy old nationals tests since they sell all of them together, I think.

By the way, has everyone been getting Lugol's and Benedict's solutions at their competitions? The rules say that they are supposed to provide them, but I didn't get them at an invitational AND state, which really screwed us up.

How would you tell sucrose from glucose without the Benedict's?

Re: Forensics?

Posted: April 3rd, 2009, 9:31 pm
by dudeincolorado
eww... that's mean I'm not sure about this but when I tested it glucose caramelizes a light amber while sucrose caramelizes a dark brown. But don't take my word for it.

Re: Forensics?

Posted: April 3rd, 2009, 11:40 pm
by chzlover3
wexs883198215 wrote:Hey, watts,

You can go to http://www.scioly.org/wiki/2009_Test_Exchange for some tests. You can buy old nationals tests since they sell all of them together, I think.

By the way, has everyone been getting Lugol's and Benedict's solutions at their competitions? The rules say that they are supposed to provide them, but I didn't get them at an invitational AND state, which really screwed us up.

How would you tell sucrose from glucose without the Benedict's?
Indiana state gave us Benedict's; not sure about Lugol's. [My partner did powders while i was doing fibers]
But yeah, that's really lame that they didn't give you those, especially lame that you didn't get them at state!!


I'm not sure how you'd tell them apart without Benedict's...you just...NEED Benedict's!! :lol:

Re: Forensics?

Posted: April 4th, 2009, 5:18 am
by adam124218
Lugol's is Iodine. We had it at Indiana State.

Re: Forensics?

Posted: April 4th, 2009, 8:35 am
by dholdgreve
wexs883198215 wrote:Hey, watts,

You can go to http://www.scioly.org/wiki/2009_Test_Exchange for some tests. You can buy old nationals tests since they sell all of them together, I think.

By the way, has everyone been getting Lugol's and Benedict's solutions at their competitions? The rules say that they are supposed to provide them, but I didn't get them at an invitational AND state, which really screwed us up.

How would you tell sucrose from glucose without the Benedict's?
Check the Yahoo Coaches Group for many past invitational tests as well:
http://groups.yahoo.com/group/science-o ... 20test.pdf

A few other misc comments based on previous posts:

I believe the purpose of the cobalt blue glass is to mitigate (i.e. filter out) the blue flame of the bunsen burner, so you can see the true color of what is burning.

Lugol's Solution is actually a mix of Potassium Iodide (aq) and Iodide crystals, and can easily be mixed in the lab... No reason that an Event Coordinator should not provide this as well as Benedict's... I'd file a formal protest, or the same Event Supervisor will be back next year doing it to you again.

FYI, I2KI(Lugol's) can only be sold in quantities up to 1 ounce due to it's secondary use in the production of meth, so it really needs to be developed in the lab, and put in your dropper bottles. See wikipedia for more info.

Re: Forensics?

Posted: April 5th, 2009, 8:15 pm
by wexs883198215
Ok, thanks. They can expect a protest from me if they pull this at state again :D

Re: Forensics?

Posted: April 7th, 2009, 11:35 am
by dyt
Umm i was just wondering when you are doing the temperature tests, is are there any that dont change?? That info would be greatly appreciated. Or if u could just seperate them, endo. exo. so i can check my info with urs thanks :] :geek: