Six unknown organic compounds

Question

Hi!

I need help with a chemistry question:

Question: You have six organic compounds in different test tubes. They are:

1. Stearic acid
2. 1-Cyclohexene
3. 1-propanol
4. Sodium acetate
5. Heptane
6. Benzoic acid

You do not know exactly which organic compound is in which test tube. Suggest one / several methods to be able to find out which organic compound is in which test tube

My thoughts:

I think I should firsly measure pH-value because sodium acetate is the only base here, so I'll know that from the high pH value since it is a strong base. And benzoic acid should be pretty acidic here. So I'll get those covered. But are there any other ways? From there I can try to check the solubility of the compounds in the remaining test tubes. Heptane and 1-cyclohexene will not be so soluble in water, but propanol should be more soluble?? Ahh I feel so confused here and I would really appreciate help!

Thanks,

Answer 1

Stearic acid, sodium acetate and benzoic acid are solids.

Cyclohexene, propanol and heptane are liquids.

Propanol will be miscible with water. Might be able to differentiate cyclohexane and heptane by boiling points if they differ enough.

For the solids, you are correct that sodium acetate solution should be alkaline. Then to differentiate stearic acid and benzoic acid, benzoic acid is soluble in water and stearic acid is not. You could also use melting points to differentiate them.