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Can't Judge A Powder B

Posted: September 5th, 2022, 6:53 pm
by bernard

Re: Can't Judge A Powder B

Posted: October 25th, 2022, 11:00 am
by bozodo44
Hi - How do we find a specific gravity of a sample? I went online but wasn't sure if I fully understood the concept as seems like it's just the measure of density. I don't have a scientific background so thanks in advance. Other than this formula that I picked up: SG: density of object\density of water.

Re: Can't Judge A Powder B

Posted: October 30th, 2022, 2:37 pm
by drcubbin
Easy peasy. Here is a video that gives a very simple explanation for measuring the Specific Gravity of a solid. Once you understand this, look at other videos on YouTube (your very best SciOly friend!) to find how to measure other substances. https://youtu.be/yGnNE-MWDV4

Re: Can't Judge A Powder B

Posted: October 30th, 2022, 6:42 pm
by Peiyinglovesscience
Hello, what does “visible gas” mean?, it is stated in the “adding powder to liquid section”? Also for measurements, will points still be awarded if the measurement written down is close to exact, but not exactly exact?

Re: Can't Judge A Powder B

Posted: November 4th, 2022, 11:32 am
by EllaYu
For this event how much powder will be given? Will hot water be given during the event too?

Re: Can't Judge A Powder B

Posted: November 5th, 2022, 2:34 pm
by Chemical-Reactions
How do the types of ions affect a solution's conductivity? - Travis Y

Re: Can't Judge A Powder B

Posted: November 7th, 2022, 6:23 pm
by knightmoves
EllaYu wrote: November 4th, 2022, 11:32 am For this event how much powder will be given?
That's up to the event supervisor. Each team will be provided with the same quantity of the powder, and you can reasonably assume an adequate quantity to conduct multiple tests, but it would make sense to plan on being economical with the powder you are given.
EllaYu wrote: November 4th, 2022, 11:32 am Will hot water be given during the event too?
Read rule 2d and 2e. You are guaranteed to get NaOH, HCl, and distilled water (room temp!) in a wash bottle. You may get almost anything else the ES decides to give you, which might include a hot plate, or hot water, or might not.

Re: Can't Judge A Powder B

Posted: November 16th, 2022, 12:47 pm
by g-gills
How could the size of individual particles be measured?

Re: Can't Judge A Powder B

Posted: November 17th, 2022, 4:33 am
by drcubbin
Peiyinglovesscience wrote: October 30th, 2022, 6:42 pm Hello, what does “visible gas” mean?, it is stated in the “adding powder to liquid section”? Also for measurements, will points still be awarded if the measurement written down is close to exact, but not exactly exact?
I don't think they really mean "visible gas", such as nitrogen dioxide or chlorine gas (neither of which you will see unless you - hopefully - take organic chemistry later on). I think they are simply referring to smoke or "steam", such as what you would see when adding HCl to various compounds. Make sure you document all of these reaction observations.

Re: Can't Judge A Powder B

Posted: November 17th, 2022, 4:38 am
by drcubbin
knightmoves wrote: November 7th, 2022, 6:23 pm
EllaYu wrote: November 4th, 2022, 11:32 am For this event how much powder will be given?
That's up to the event supervisor. Each team will be provided with the same quantity of the powder, and you can reasonably assume an adequate quantity to conduct multiple tests, but it would make sense to plan on being economical with the powder you are given.
EllaYu wrote: November 4th, 2022, 11:32 am Will hot water be given during the event too?
Read rule 2d and 2e. You are guaranteed to get NaOH, HCl, and distilled water (room temp!) in a wash bottle. You may get almost anything else the ES decides to give you, which might include a hot plate, or hot water, or might not.
Yes, be as "economical" as possible! When running this event, we often see students who have not practiced the hands-on parts chemistry events using the materials as if they are baking a cake! I always make a point of letting teams know that powders and liquids will NOT be replenished, but we still get a few who think this is baking class and use too much - especially powder.