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Re: Crime Busters B

Posted: January 24th, 2018, 7:00 am
by Tailsfan101
Also, zinc has a higher density and fizzes with HCl.

Re: Crime Busters B

Posted: January 31st, 2018, 8:34 am
by Benewcomb
Would we have to know the difference between types of plastic? Because I haven’t gotten to check if we have that information in our binder.

Re: Crime Busters B

Posted: January 31st, 2018, 2:04 pm
by Tailsfan101
Benewcomb wrote:Would we have to know the difference between types of plastic? Because I haven’t gotten to check if we have that information in our binder.
Plastics you need to differentiate:
PETE
HDPE
PVC
LDPE
PP
PS
PMMA

Re: Crime Busters B

Posted: January 31st, 2018, 3:28 pm
by Benewcomb
Tailsfan101 wrote:
Benewcomb wrote:Would we have to know the difference between types of plastic? Because I haven’t gotten to check if we have that information in our binder.
Plastics you need to differentiate:
PETE
HDPE
PVC
LDPE
PP
PS
PMMA
K thanks. I’m on it.

Re: Crime Busters B

Posted: February 4th, 2018, 2:07 pm
by pandascienceolympiad
Birdmusic wrote:Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?
1) Try to not mix the flour or cornstarch in water first. Also, your solutes and solvents might be old, try using newer ones.
2) Try looking at the mixture under a microscope first, and try and come up with possible powders it could be based on your results

Re: Crime Busters B

Posted: February 6th, 2018, 6:48 pm
by Birdmusic
pandascienceolympiad wrote:
Birdmusic wrote:Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?
1) Try to not mix the flour or cornstarch in water first. Also, your solutes and solvents might be old, try using newer ones.
2) Try looking at the mixture under a microscope first, and try and come up with possible powders it could be based on your results
Thank you! We got a new KI, and it seems to work much better.

Re: Crime Busters B

Posted: February 7th, 2018, 1:09 pm
by lamppost
I'm also new to this event and I'd like to know-are we allowed to put charts on our sheets? Or should we not waste pages on that and fill it with other useful info?

Re: Crime Busters B

Posted: February 7th, 2018, 1:53 pm
by shrewdPanther46
There is nothing saying you cannot have charts on your cheat sheet. You can put whatever you want...

Re: Crime Busters B

Posted: February 7th, 2018, 3:02 pm
by Tailsfan101
lamppost wrote:I'm also new to this event and I'd like to know-are we allowed to put charts on our sheets? Or should we not waste pages on that and fill it with other useful info?
2018 Crime Busters rules wrote:...Teams may bring five double-sided 8.5" x 11" sheets of paper with information from any source.

Re: Crime Busters B

Posted: February 14th, 2018, 6:53 am
by Polarrr
lamppost wrote:I'm also new to this event and I'd like to know-are we allowed to put charts on our sheets? Or should we not waste pages on that and fill it with other useful info?
I think that putting charts for helping with powder and fiber identification would be useful... you do have five sheets front and back and you'd be surprised how much you can fit on there.