Can't Judge A Powder B

[lwalko]

We know that checking pH, temperature, and conductivity of the substance with distilled water is a good idea. And we're guessing that checking pH with HCl and NaOH is a appropriate, but should temperature and conductivity of the substance in HCl and NaOH be checked as well? In some places this seems to be recommended, but in other places it says to only do these tests with the water.

[knightmoves]

We know that checking pH, temperature, and conductivity of the substance with distilled water is a good idea. And we're guessing that checking pH with HCl and NaOH is a appropriate, but should temperature and conductivity of the substance in HCl and NaOH be checked as well? In some places this seems to be recommended, but in other places it says to only do these tests with the water.

What do you think you're accomplishing by "checking pH with HCl"?

You're not controlling either the quantity of acid or the quantity of powder that you have. Are you trying to determine that an acid-base reaction has occurred by comparing the pH of the HCl with the pH after you combine the HCl and powder? What question would this observation help you answer?

As far as the conductivity tests go, I have two answers for you.

The first answer is that I can't see any plausible way that a random quantity of either HCl or NaOH solution mixed with a spatula full of some powder or other wouldn't be conductive, so it seems like this test is completely worthless.

The second answer is that I have seen tests that ask precisely this question - if the sample is soluble in NaOH, is the solution conductive?

So despite the fact that it's a really stupid question, I think you ought to be prepared to answer it.

[zl-mi]

Is it necessary to test powder aqueous solution with HCl, NaOH, etc? Thank you.

[randomdogonapc]

In my opinion, yes. Me and my partner just try to make as many thorough observations about anything. I believe there is more info on the wiki page about what to test.