[eleon]

Hello!

I work as a lab assistant at an educational facility and my professor has noticed that our yields for MgCl2 resulting from Mg + HCl are consistently too low. I've run and re-run the experiment looking for what may be causing the trouble, but have so far found nothing. We use 25 ml of 3.0 or 3.5 M HCl and masses of Mg ranging from .2 - .9 grams. This is a pretty standard reaction lot's of first year students will do. Anyone with experience with these reaction aware of what might be causing lower than expected yields?

[Arkcon]

How are you determining the reaction goes to completion, is some Mg possibly left?  How are you determining the amount of magnesium chloride, are you losing some in that assay.

[Borek]

Stoichiometry looks more or less OK, although 25 mL of 3 M is barely enough for 0.9 g of Mg, so I would use slightly higher excess.

How do you collect MgCl₂? Just by drying out?