[naclh2oquestion]

I'm trying to get my cousin interested in chemistry so I want to show him HCl + NaOH H₂O + NaCl. I then want to make the resulting NaCl precipitate out of the solution to show that's what happened. I want to do this because it is a really simple equation with products that are easy to understand and she's only in 4th grade.

In preliminary testing I have tried adding 91% isopropyl alcohol but there wasn't really a precipitation as much as there was a milky-white brine layer at the bottom of the solution. I've looked up substances that NaCl isn't soluble in and from what I've found it's most weakly soluble in ethanol. This would be okay if I could buy a pint of the stuff but I'd have to buy a gallon of denatured alcohol from Lowe's and I don't want or need that much.

Obviously the suggested liquid shouldn't react with NaOH or HCl in case there is any residual left in the solution.

Do you have any better suggestions? Thanks.

[Babcock_Hall]

It sounds as if a precipitate formed too quickly, as opposed to crystals forming (I am assuming that you were hoping to see crystals).  It might be possible to add an alcohol drop-by-drop with swirling, but I have never tried it.

[AWK]

I advise against using even very diluted NaOH in the presence of children. The use of dilute acid and base solutions gives solutions that will not precipitate salt even by the addition of large amounts of alcohol or acetone. It is better to demonstrate the chemical reaction by mixing acetic acid with sodium carbonate or bicarbonate.

[naclh2oquestion]

I advise against using even very diluted NaOH in the presence of children. The use of dilute acid and base solutions gives solutions that will not precipitate salt even by the addition of large amounts of alcohol or acetone. It is better to demonstrate the chemical reaction by mixing acetic acid with sodium carbonate or bicarbonate.

May I ask why specifically the NaOH? Proper chemical handling precautions will be taken, i.e. goggles, nitrile gloves, appropriate attire, high ventilation area (outside), and he will not touch any of the reactants. And we've already done the baking soda and vinegar reaction, the appeal of this one is combining two very reactive things to produce an extremely benign product.