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Anyone have any tips for how to differentiate from Sodium Acetate and Sodium Chloride?

I start with a flame test then test HCl for carbonate. After this, how can I reliably tell these two apart? I know NaOH is a possibility (NaCl dissolves slowly?), but I want something that isn't completely subjective....

C8H10N4O2! wrote:Anyone have any tips for how to differentiate from Sodium Acetate and Sodium Chloride?

I start with a flame test then test HCl for carbonate. After this, how can I reliably tell these two apart? I know NaOH is a possibility (NaCl dissolves slowly?), but I want something that isn't completely subjective....

Try testing pH.

Any tips for differentiating horse and cow hair? They look the same to me under a microscope... both appear to have thick and black medulla.

random-username wrote:Any tips for differentiating horse and cow hair? They look the same to me under a microscope... both appear to have thick and black medulla.

I think horse hair generally has a thicker medulla and cattle hair has ovoid bodies

Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

c21k wrote:Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

Guessing you went to the Solon Invitational?

c21k wrote:Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

I have notes on how transparent the plastics are but that's about it. It's hard to differentiate between the opaque plastics because they all look the same, so I have no clue how the testmakers intended for it to be done.

LostInTheSauce wrote:

c21k wrote:Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

Guessing you went to the Solon Invitational?

Haha, yep! I was so lost on the plastics...

jimmy-bond wrote: I have notes on how transparent the plastics are but that's about it. It's hard to differentiate between the opaque plastics because they all look the same, so I have no clue how the testmakers intended for it to be done.

hmmm yeah, that's what I'm trying to figure out right now

LostInTheSauce wrote:

c21k wrote:Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

Guessing you went to the Solon Invitational?

The Solon Invitational forensics was absolutely insane. My partner's first time doing it, so I had her literally just read and make lists of the suspects/what would implicate them. That alone took her 10 minutes (but she did find a bonus at the end of the instructions). We were lost at what to do with the plastics so I just put them in water and guessed from there... yikes... At least we got the person right. Any tips for how to divide/conquer better at regionals?

olhs4n6 wrote:

LostInTheSauce wrote:

c21k wrote:Does anyone have some advice on how to identify a given plastic sample?

(no burn tests permitted, no solutions of different densities or indices provided)

Guessing you went to the Solon Invitational?

The Solon Invitational forensics was absolutely insane. My partner's first time doing it, so I had her literally just read and make lists of the suspects/what would implicate them. That alone took her 10 minutes (but she did find a bonus at the end of the instructions). We were lost at what to do with the plastics so I just put them in water and guessed from there... yikes... At least we got the person right. Any tips for how to divide/conquer better at regionals?

Wow, what a way to start! Props to your partner for surviving it and living to tell the tale For the division of material, my partner and I split the qualitative analysis. Then we assign other material based on our strengths. The leftovers we both study so that whoever finishes their section of the test can just do those parts. I also find that allotting time for specific areas of the test can be helpful for pacing purposes.